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OILS AND FATS IN NUTRITION AND HEALTH: 2. CHEMISTRY, DIGESTION AND METABOLISM

S.H. GohForest Research Institute of Malaysia

Abstract: Nutrition and dietary recommendations have been reviewed and it is now known that in general most individuals have independent requirements. Generally nutritional requirements need to present trends of comfortable living, lack of physical activity, easy availability of convenience and fast foods and mass production of high glycaemic carbohydrates and sugars. And together with the over-consumption of readily available and subsidised soybean and canola oils (including their hydrogenation products) particularly in N. America and many developed countries, the apparent lack nutritional measures has led to problems of obesity, insulin resistance, type II diabetes, CVD, macular degeneration, undesirable effects to foetuses and possibly cancer. Natural oils and fats as macronutrients are now considered with low glycaemic carhohydrates together with vegetables/fruits to be at the base of the food pyramid. Fats are recognised to provide balance of saturation, monounsaturation and polyunsaturation with the consideration for adequate amounts of n-3 by limiting the n-6 linoleic acids which are in overabundance. Fatty acids cause chemical and nutritional consequences from their chain length and their attachment to the 1-, 2- and 3-positions of glycerol in triglyceride fat molecules. Natural vegetable oils and fats usually have unsaturated fatty acids at the sn-2 position and are readily absorbed. Having long-chain saturated fatty acids at the glycerides cause reduced digestion by the lipase enzymes and reduced or slow absorption as well. Natural or processed glycerides can be made to suit the particular needs for food and nutrition. Palm Oils. The oils from oil palm fruit (major) and kernel (minor) provide an excellent choice for food manufacturers because of their versatility and nutritional benefits. Palm oil and many other fats (cottonseed, peanut, cocoa butter and shea/illipe butter) are naturally structured to contain predominantly monounsaturated oleic acid (major) and polyunsaturated linoleic acids at the sn-2 position in the major triacylglycerol molecules to account for the beneficial effects described in numerous nutritional studies showing that palm oil is typically representative of a monounsaturated oil. For example, palmolein provides as good as or better blood lipid profiles than extra virgin olive oil in human studies, very much due to the oil molecules being naturally structured to have predominantly oleic and linoleic acids at the sn2 position which are more readily absorbed by the body than the palmitic acid moieties which are mainly at the 1,3-positions of the glyceride molecules. Mild solvent-free oil extraction of the palm fruit and fractionation of the extracted oil provides a major liquid oil ( palmolein; excellent for cooking and deep frying), semi-solid fats (for chocolate and confectionery) and solid stearin fats for margarines, bakery needs and shortenings. Oil quality and nutritional benefits have been assured for the variety of foods that can be manufactured from palmolein and other palm oil fractions directly or as blends (physical or interesterified) with other types of oils while remaining free of trans fatty acids. Thermal and oxidative stability is ensured by the presence of high amounts of the antioxidant vitamin E and the chemical constitution of moderately high mono-unsaturation. Palm nut kernels are another useful oil resource, providing liquid and solid oil fractions for specialized applications such as medium chain triglyceride (MCT) oils, as solid confectionery fats and for improving organoleptic properties after interesterification, apart from well known uses as oleochemicals. 2-Positional unsaturation in oils and fats. As a naturally structured oil, palm oil provides the 2-positional fatty acids that are mainly mono-unsaturated (65%), partly polyunsaturated (22%) but only 13% saturated. The major marketed palm oil fraction, palmolein, has about 66% mono- and 30% poly-unsaturates but only 4% saturated acids at the 2-position in the glyceride molecules. Furthermore, the saturated fatty acids consist of palmitic and stearic acids that are shown to have relatively weak effects in blood cholesterol elevation. It is now recognized that dietary contribution to nutrition and health is the outcome of various foods; the contribution of fats depends not only on the nature of fatty acids but also the fat source (glyceride structure and other components). In digestion, enzymatic hydrolysis of palm oil glycerides containing predominantly oleic acid at the 2-position and palmitic and stearic acids at the 1- and 3-positions allows for the ready absorption of the 2-monoacylglycerols containing unsaturated fatty acids while the saturated free fatty acids are absorbed less readily. Due to the nature of lipase 1,3-specificity of action in digestion and metabolism, several lipidaemic consequences may be observed. Thus, in human studies palmolein provides similar or better blood lipid profiles in terms of TG (triglyceride), LDL and HDL when compared to canola, extra virgin olive oil and high oleic sunflower. Various other effects of a variety of oils and fats can also be clarified - anti-obesity effects of diglyceride oils, low cholesterolemic effect from milk fat consumption, effects of low and high sn-2 palmitic oils in infant formula, slightly elevated calcium excretion from sn-1 & -3 long chain saturated fatty acids, behaviour of structured fats and MCT and postprandial TG observations on natural and interesterified stearic-rich fats. The anti-thrombotic property of palm oil is related to the structuredness of the triglycerides as well as the presence of micronutrients such as tocotrienols. The digestion and absorption of glycerides are influenced by the blending of

Malaysian Oil Science and Technology 2006 Vol. 15 No. 2 43

Oils and Fats in Nutrition and Health: 2. Chemistry, Digestion and Metabolism

different oils and other food matrices so that the kinetics of the action of lipases can be altered or that acyl-migration can occur with subsequent changes in nutritional effects.

General IntroductionGeneral dietary considerations have been covered previously in Part 1 [Goh, 2006]. There is now a better understanding about diet particularly the relationship of various diets, lifestyle and other environmental factors to major health problems such as obesity, diabetes, cardiovascular diseases (atherosclerosis, stroke, heart diseases), and possibly other diseases (cancer, cystic fibrosis, diabetes, inflammatory diseases, macular degeneration, Parkinson’s and Alzheimer’s disease). Although many questions on nutrition remain unanswered, there is the consensus view that there should be moderate intake of proteins to include all essential amino acids, sufficient intake of minerals, essential fatty acids, micronutrients (vitamins, etc) and fibre, and a balanced (not excess) intake of macronutrient energy foods such as carbohydrates, oils and fats [Weinberg, 2004; Willett, 2000, 2001]. The world faces a situation of an easy availability of high caloric, processed food and it becomes important to have a balance not only of intake of types of foods, rate of intake and expenditure of energy foods but also of adequate amounts of other essential nutrients. Central to general dietary recommendations is the adequate provision of essential nutrients (protein, carbohydrate, essential fatty acids, vitamins and micronutrients) where a balance (not excess) can be optimally achieved while attention is paid to the enjoyment of glorious food [Willett, 2001; Noakes & Clifton, 2005]. In the quest to achieve satiety and also health from the numerous categories of food available, preferences have to be made and have been summarized [Goh & Tang, 2005; Goh, 2006; Weigle et al, 2005]. Considerations of practical choices of dietary components, healthy cooking and moderation of portions have also been described. On the basis of the presently easy availability of foods, moderate consumption of preferred proteins could be from fish, fresh white meat and from vegetable sources (legumes, beans and nuts). Carbohydrates are the most readily available food but low glycaemic varieties are specially preferred, e.g. unprocessed whole grain foods, in contrast to the widely available processed varieties. Low or negative-calorie vegetables and fruits are recommended in high portions for their vitamins, micronutrients, minerals and fibre. As to oils and fats these will be treated in more detail below but the major problem has now been recognised as due to the overwhelming availability of major polyunsaturated oils which have caused an imbalance of nutritional requirements. In particular, widespread hydrogenation has given rise unhealthy trans and other unnatural fats. Recommendations are for dietary fats which require no hydrogenation and having a balanced fatty acid composition, with particular provision for sufficient 3 fatty acids [Mohd et al, 1996; Salmi, 2004].

Dietary Oils and Fats

Nutrition is a complex issue and in relation to oils and fats, dietary recommendations over the years have been controversial as most have been biased due to socio-economic, cultural and geopolitical reasons. Presently much more is known of dietary oils and fats and the decades-old controversy on heart-diet-cholesterol hypothesis has also dissipated in the light of new findings [Hu & Willett, 2002; Kotte, 2003; Weinberg, 2004; Ordovas, 2005; Lefevre et al, 2005]. Central to the misconception is the idea that lowering blood total cholesterol by dietary polyunsaturated acids such as linoleic acid (18:2) and/or by a low cholesterol/low saturated fat diet will be the end-all of the prevention of cardiovascular diseases [Tholstrop et al, 2003; Thijssen & Mensink, 2005; . Unfortunately this idea is based more on socio-economic (e.g. to support a major edible oil industry) and cultural reasons rather than proper science. Excessive linoleic acid consumption is now not favoured as the polyunsaturated acid is proinflammatory and competes with beneficial 3 (or n-3) oils which are normally in short supply from available foods [Felton et al, 1994; . Further, as the majority of prepared foods need semi-solid oils and fats which cannot use polyunsaturated oils directly, there has been the unfortunate popularisation of hydrogenating the oils leading to the subsequently proven detrimental health effects of trans fatty acids and possibly other unnatural glycerides [Ascherio & Willett, 1997; Federal Register, 2003; Fallon et al, 2005; Estruch et al, 2006; Stender & Dyerberg, 2003].

Oils and fats are energy-dense macronutrients required by the body for energy, cellular construction, brain/nervous tissue, conveyer of lipid soluble micronutrients and cellular communication. It is the general consensus view that to meet these needs a variety of fatty acid types from available food sources of oils and fats are required. These come from monounsaturated (e.g. oleic acid or 18:1), saturated (e.g. palmitic or 16:0), polyunsaturated (-linoleic acid, 18:3 n-3) or long chain polyunsaturated acid (e.g. DHA or 22:6 n-3). Added to these are the needed small amounts of antioxidant vitamins, notably vitamin E and/or its analogues [Gee & Goh, 2006].

Figure 1. Shapes of fatty acid molecules: trans “opposite” and cis “same side”

Monounsaturation refers to the presence of one double bond in the fatty acid molecule to which hydrogen can be added to, hence processing by hydrogenation can be used to obtain a saturated fatty acid. In the process of partial hydrogenation



unfortunately the normal geometrically cis (“same side” or Z) chemical structure can be transformed to the trans (“opposite side” or E) with an accompanying change in physical and biological properties (Fig. 1). While the need is to be more like saturated fats which have no double bonds but have many desirable organoleptic and processing properties for numerous foods, e.g. palatability, flavour, plasticity, controllable melting points and rheology, the changed trans fats turn out to have the most undesirable biological properties of all fats such as raising bad LDL cholesterol, lowering good HDL cholesterol, raising Lp(a) levels, raising triglyceride (TG) levels and interfering with many cellular signalling pathways.

Many of the detrimental effects of trans fats are related to CVD, chronic diseases, cancer and various disease states, the unborn foetus and others as more new findings emerge. Cholesterol, long known to be needed for human health, biosynthesis of sex hormones and intelligence, is now a cause of concern if levels in blood are too low (<160 mg/dL or 4.1 mmol/L) or too high (>240 mg/dL or 6.2 mmol/L) as the latter may be due to a genetic condition (familial hypercholesterolemia) or unhealthy living conditions (low physical activity or stress), especially when compounded by other unhealthy dietary and lifestyles. Relatively high blood cholesterol per se, even as caused by diet, may not be the cause of CVD as shown by the example of the French paradox and for some Mediterranean countries where positive influences of marine food intake, high intakes of micronutrients from vegetables/fruits and a low-stress lifestyle including the consumption of moderate amounts of red wine. Further, overall considerations of non-genetic factors causing CVD mortality surprisingly seem to favour those with moderate to slightly high levels of cholesterol, especially for the elderly and women.

For a long time oils and fats have been assumed to be just fatty acids and simplistically classified as saturated, monounsaturated and polyunsaturated and this has caused many discrepancies as other details such as chain length, nature of the unsaturation and glyceride structure were omitted. Fig. 2 shows the fatty acid compositions of some oils and fats, including those produced by man/woman. When once the overemphasis is on saturation and polyunsaturation, it is now noted that the desired types of dietary fatty acids should be close at those produced by the body, even as this has seldom been considered except for infant formula. It may be noted that among the major oils, it is palmolein that most closely resembles the fatty acid profile of human fat.

Recent recommendations also consider the importance of good HDL cholesterol and the ratio total cholesterol/HDL becomes a useful index. This indicates that lowering total cholesterol should be accompanied by raising (or not lowering) the HDL cholesterol. The cholesterol lowering effect of linoleic acid (18:2, a polyunsaturated acid) is well known but is accompanied by lowering the good HDL cholesterol, and also

compounded by increasing inflammatory and oxidative stress factors [Sulzle et al, 2004; Kang et al, 2005]. On the other hand, the saturated myristic acid (14:0) is known to have the highest cholesterol-raising effect but this is balanced by the elevation of HDL cholesterol and endothelial nitric oxide [Zhu & Smart, 2005]. Lesser HDL cholesterol-raising effects are shown by other saturated fatty acids such as lauric (12:0) and palmitic acids while oleic acid is relatively neutral or slightly elevating. Based on these considerations high consumption of oleic acid relative to the other two major fatty acids is usually recommended. While the polyunsaturated linoleic acid is well known to lower total cholesterol, there remain many important concerns, e.g. decreasing the good HDL-cholesterol, its pro-inflammatory properties, its competition with the more scarce but essential LC polyunsaturated n-3 (or 3) fatty acids and also the increase of oxidative stress. Therefore, a limit has now been recommended for the consumption of linoleic acid (18:2 n-6), particularly by ISSFAL (Fig. 3) [Gunstone, 2005].

Figure 2. Fatty acid compositions of biosynthesised human fat and milk and comparison with some major oils [range for humans indicate range observed due to influence of dietary fat even when determined for low fat diets]

Apart from the cholesterolemic effects of the different fatty acids, it is now known that the digestion, absorption and metabolism of the different fats are in many cases



more important than just considering the chemical nature of the individual fatty acids. Fats are triglycerides or triacylglycerols and not just fatty acids and natural triglycerides can be structured or stereo-structured. The digestion and absorption of fat foods then become very important as these determine the uptake of the fatty acids, their reconstitution in the body and their storage or conversion to energy and other metabolic effects

Furthermore, oils and fats as triglycerides need to be broken down enzymatically when consumed to be absorbed by the alimentary tract and reconstituted to triglyceride oil molecules again as chylomicrons in the circulatory system. In this process of digestion and absorption, important differences are also shown in the intrinsic nature of different oils and fats. The structures and consequences of their digestion and absorption are shown in scheme (Fig. 3). It is therefore important to consider not just the nature of fatty acids but also the positions they occupy in the triglyceride or triacylglycerol structures. Important consequences have been known from empirical data. Notably, for example, palm oil contains saturated acids at the 1- and 3-positions of the glycerol moiety while the mainly unsaturated acids that are well absorbed in the major 2-monoacyglycerol pathway, are those at the 2-position.

Figure 3. Structures of the oil or fat molecule as triacylglycerol with 1,2,3-positional fatty acids

The nutritional value of oils and fats is much dependent on the chemistry (or nature) of the fatty acids and the structural effects of the glyceride molecule, especially the positioning of the fatty acid molecules. The nature of the fatty acids can be seen from the chemical compositions, some of these being given in Fig. 2. The world’s supplies of fatty acids are now dominated by a few major crops and these are given in Fig. 4. It is noted that no major oil crop can provide the total fatty acid profile of human fat or milk; palmolein seems to provide a composition which is close. However, nowadays conventional wisdom takes into account of the balance of saturated, monounsaturated and polyunsaturated as well as the 3 fats. Cholesterolemic effects put some limits to saturated and polyunsaturated fats while monounsaturated fats are favoured as they are considered neutral. Higher limits are placed on the polyunsaturated linoleic acid (a 6 acid) because of concerns of proinflammatory and oxidizability effects as well as its competitive effect against beneficial 3 fatty acids [Burdge, 2004]. The ISSFAL recommendation is also given and compared to the world’s supply of fatty acids [Gunstone, 2005].

Since many of the commercial oils and fats cannot be compatible with the ISSFAL recommendations, suitable blending can be attempted. Palmolein and canola both provide the greatest sources of oleic acid with the former providing palmitic acid while the latter providing adequate amounts of 3 acid needed by the body. Ideally 3 should be long chain polyunsaturated oils (of marine origin) but the normal chains can usually be of some benefit, more especially for women. Considering fatty acids blends, without the effect of positional fatty acids, a 50% blend of palmolein and canola can provide for the ISSFAL recommendation. However, if the positional effects due to enzymatic digestion and absorption are factored in, palmolein is optimal considering the Truswell’s data (below) and 20-50% canola blends are suitable (Fig. 5) [Truswell, 2004].



0%

20%

40%

60%

80%

100%

% F

atty

Aci

d Ty

peMajor Oils and Fats, Total Supply & ISSFAL Recommendation

18:3n-318:2n-6oleicstearicpalmiticmyristiclauric

Figure 4. Comparison of the fatty acid compositions of major oils, the overall world supply and ISSFAL recommendation [*Gunstone, 2005]

0%

20%

40%

60%

80%

100%

ISSFAL Recommendation & Suitable Oil Blends

Linolenic 18:3 n-3Linoleic 18:2 n-6MonounsaturatedSat. 12:0 to 18:0

Figure 5. Comparison of the world’s supply of fatty acids, ISSFAL recommendation and palmolein blends. [Palmolein-sn2 refers to 70% preferential absorption of sn-2 fatty acids; palmolein-sn2+canola20% refers to the previous consideration plus a blend with 20% canola oil; palmolein+canola50% considers the fatty acids as randomly distributed in an equal mixture of palmolein and canola and without positional effects]



Triglyceride Structure and Enzymatic DigestionThe nutritional effects of dietary oils and fats are influenced by several factors as tabulated in Appendix 1. Of particular concern are the cholesterolemic effects (e.g. LDL-c, HDL-c, Lp(a), TG levels, etc) exerted by the nature of oils and fats. The effects of saturation, unsaturation, polyunsaturation, chain length and trans structures of the fatty acids have been well researched on. Oils and fats being glycerol esters of fatty acids need to be acted on by digestive enzymes before they can be absorbed. The absorbed 2-monoglyceride and fatty acids are reconstituted to oils and fats again to be conveyed by the circulatory system. Digestive enzymes are very selective or stereoselective, i.e. they can distinguish as right-handedness or left-handedness to 1,3-positional distributions of the fatty acids in the glyceride molecule. As fatty acids are usually long chain and not overly different in the usual oils and fats, the 1- and 3-positions are more or less similar so that the digestive enzymes are mainly 1,3-specific, i.e. 1,3-positional fatty acids are cleaved preferentially in comparison to those of the 2-position. After cleavage, fatty acids and 2-monoglycerides are obtained which are absorbed if there

is no other interference. After the action of pancreatic lipase the intestinal medium allows the formation of fatty acid soaps of calcium and magnesium which are insoluble if the fatty acids have saturated long chains. Such soaps are consequently poorly absorbed. Fig. 6 shows diagrammatically the digestion of oils and fats, absorption of 2-monoglycerides and fatty acids and further reconstitution back as oils and fats [Goh, 1999, 2001; Goh et al, 2004].

The literature records numerous studies on fatty acids, cholesterol, commonly encountered fatty acids, trans fatty acids, essential 3 fatty acids, conjugated fatty acids and their effects on health. Selected data given in Table 1 below summarises a large number of data related to the observed dietary outcomes from positioning of fatty acids in the glyceride molecules, saturated/unsaturated fats, naturally structured fats such as palm and cocoa butter, diglyceride oils and structured fats of commercial interest. Digestion and absorption of various oils and fats are governed by the lipase enzymatic activity within the digestive juice matrices of the stomach and the small intestine where the structure and positioning of the fatty acids play important roles.



Figure 6. Enzymatic digestion of glycerides and absorption of 2-monoacylglycerol/fatty acids

Consequences of this scheme are well supported and in fact provide explanations of many controversial observations, as may be outlined below:-

Palm oil is not hypercholesterolemic in contradiction to its relatively higher saturation while other related fats such as lard which is known to be cholesterolemic due to the differently attached position (sn-2) of the majority of saturated palmitic acid in the glycerides.

Palmolein provides a better blood cholesterol profile as compared to virgin olive oil (Fig 7). The major pathway in the digestion/absorption scheme provides for ready absorption of monounsaturated and polyunsaturated fatty acids while direct absorption of saturated palmitic acid

directly or via the phosphatidic pathway is estimated to account for only as much as 30% of the total present.

While adults may not need too much dietary fat due to ready availability of other caloric foods, infants and farm animals need lots of fats for growth especially the saturated palmitic acid. To allow this acid to be readily absorbed slight processing by interesterification may be needed to provide incorporation of more 2-positional palmitic acid. It is also well known that infant formula needs to incorporate essential long chain 3 fatty acids at the 2-position for ready absorption.

Intrinsic in the scheme of digestion and absorption is that long chain saturated fatty acids may have delayed absorption and that calcium



and saturated long chain fatty acids may form soaps and are probably excreted or less absorbed. Also of note, is that digestion by enzymes can be slowed down by long chain saturated fats at the 1,3-positions as evidenced in cocoa butter and substitute fats for such use.

Also as observed from postprandial (after eating) lipid profiles, the 2-positional fatty acids are much conserved in the chylomicrons (initial circulating fat particles) after absorption and postprandial profiles also indicate delayed absorption for structured fats like cocoa butter, palm oil fractions and fats structured intentionally or unintentionally with long or very long chain fatty acids at the 1,3-positions.

The selective digestion-absorption scheme explains well the rationale for diglyceride oils introduced as “anti-obesity” oils. It is clear then that with only about 30% of fatty acids in the 2-position means less fat is absorbed while a delayed absorption by the minor phosphatidic pathway of the other 1,3-positional fatty acids may allow for more fat thermolysis (burning) rather than accumulation in tissues.

Previous postprandial observations of ready digestion and absorption as well as possible ready interesterification due to short chain fatty acids, notably present in milk fats, have important implications in designing structured fats and the need to factor this in studies of fat nutrition. Newer studies have taken this into account and also explained the observation that milk fats are not hypercholesterolemic despite their high saturation due to lauric, myristic and palmitic acids. The ready enzymatic digestion of the short

chain fatty acyl esters which occur at the 3-position and in an acidic gastric medium, allows for equilibration of the initially formed 1,2-diglyceride to the predominantly stable 1,3-positions and can then lead to an equivalent of “anti-obesity” diglyceride oil. High postprandial TG lipaemia is a risk factor for CHD especially from the widespread use of stearic rich fats from hydrogenation which give rise to glycerides which are slow to digest and lipoproteins which have slow clearance.

Short and medium chain fatty acid triglycerides being readily hydrolysed by gastric lipase can influence the digestion of long chain fatty acid triglycerides due to interesterification and hydrolysis at the 1,3-positions.

Long chain saturated fatty acids at the 1,3-positions are less absorbed due to formation of calcium and magnesium soaps; possible preferential excretion of calcium is expected with such structured fats. Long chain saturated fatty acids also at the 3- and 1- positions can inhibit lipase enzyme reaction directly or indirectly due to low solubility

Structured fats have now been designed low- calorie, cocoa butter replacers using 2:0 at the sn-2 position, and 18:0 or 20:0 acids at the 1,3-positions so that easy absorption of the short chain 2:0 provides minimal energy intake while the long chain saturated acids remain poorly absorbed. Conversely use of medium chain fatty acids at the 1,3-positions and desirable or essential fatty acids at the 2-position optimizes easy digestion and fat absorption for new-borns or patients suffering from malabsorption of fats.

Table 1. Dietary and nutrition outcomes from chemical positioning of fatty acids and other aspects of fats

Study Conditions Positive outcomes Negative outcomes



Fats with sn-2 palmitic acid most beneficial in infant formula [Lien et al, 1997; Schmelzle et al, 2003]

Greater weight and head circumference in infants; better absorption in rats and avoids Ca excretion

High saturation at sn-2 position means high absorption of cholesterol-raising saturated fatty acids, which may be undesirable for some people.

Structured glyceride containing palmitic acid at the sn-2 or 1- or 3-positions for preterm infants [Carnielli et al, 1996; Lucas et al 1997; Innis et al, 1997; Rings et al, 2002; Linderborg & Kallio, 2005]

TAGs with sn-2 palmitate (similar to breast milk) beneficial for absorption, less loss as calcium soaps in stools; useful formula for preterm infants

Structured lipids now well known and long chain saturated fats at 1,3- positions are less digested and also cause some Ca excretion. MCTs are readily digested and influence the digestion of other fats.

Factor VII (coagulation): Palmitic, oleic and linoleic acids [Sanders et al 1999; Sanders et al, 2003; Tholstrup et al, 2003]

sn-2 oleic acid in cocoa butter is easily absorbed but interesterified cocoa butter causes activation of factor VII

Oleic and linoleic acids appear to have adverse effects on the endothelium function. Totally unsaturated TAGs increase FVIIa more than totally saturated ones.

Milk fat intake[ Lucas et al, 1997; Warensjo et al, 2004]

Negative correlation with CVD despite high saturation

Palmolein is less atherogenic than sunflower oil and lard in vervet monkeys with moderate fat diet [van Jaarsveld et al, 2002]

Less atherosclerosis was found with palmolein diet relative to lard and sunflower oil diets.

Palmolein not cholesterolemic [Truswell et al, 1992; Choudhury et al, 1995; Sundram, 1997; Choudhury et al, 1997]

Palmolein is comparable or better than extra virgin olive oil, canola and high-oleic sunflower oils

Glyceride structure, animal feed, atherosclerosis in rabbit [Neoh & Goh, 2003; Kritchevsky et al, 1996; Kritchevsky, 2000]

Palm oil not atherogenic despite overall relative saturation at 50%; saturation mainly at 1,3-positions

Lard and randomised palm oil glycerides more atherogenic than natural palm oil; naturally structured glycerides leads to lower absorption by poultry and swine.

2-Positional unsaturation in palm oil [Goh, 1999, 2001; Ong & Goh, 2002; Goh et al, 2004]

High unsaturation at sn-2 and saturation at 1,3-positions provide good cholesterolemic effects

Postprandial effects and structured glycerides [Aoe et al, 1997]; lipaemia from stearic acid-rich fats [Berry & Sanders, 2005]

OPO glycerides were absorbed and transported more effectively than OOP glycerides

Stearic acid, cocoa, blood pressure, CVD mortality [Hu et al 1999; Hu et al, 2001; Berry & Sanders, 2005; Buijsse et al, 2006;]

cocoa butter intake inversely correlated with blood pressure and CVD mortality

Increased intake showed exaggerated postprandial lipemia, may increase risk of CHD; increase platelet aggregation; stearic acid classified with other 12:0 to 16:0 acids

DELTA study (Ginsberg et al, 1998). Reduction of total and saturated fat from 37% to 30% and 26%.

Reduction of LDL cholesterol Reduction of HDL cholesterol.Total-c/HDL did not show improved benefit; Lp(a) rose.

LDL-cholesterol lowering is mainly from statin drugs, to a lesser extent by controlled fat diets and moderately by a strict overall diet [Jenkins et al, 2005]

Up to a total of 30% reduction can be from combined controlled fat intake and plant-foods, additional intakes of sterols, fibre, soy protein and nuts. Exercise increases HDL.

Statins can lower LDL up to 30%, sometimes with side effects; low saturated fat diet can only achieve 4.7% reduction; similar reductions can be from plant-based diet

Oxidative stress from polyunsaturated fats [Kang et al, 2005; Pamploma et al, 1998]]

Polyunsaturated:saturated oils ratio to be less than 1-1.5 for optimal oxidative stress

Life span of mammals inversely related to the peroxidizability index of mitochondrial membrane

continued Table 1. Dietary and nutrition outcomes from chemical positioning of fatty acids ….Use of long chain fatty acids (DHA Protective of sudden death and



& EPA but not 18:3 n-3) [von Schacky 2004; Wheland & Rust, 2006; Garg et al, 2006]

cardiovascular catastrophes; also of cystic fibrosis, inflammatory diseases, dyslexia and depression

Effect of -linolenic acid (18:3 n-3) conversion to long chain n-3 acid [Giltay et al, 2004; Burdge & Calder, 2005]

Women can benefit possibly because of “evolved” potential for meeting demands of the foetus

Limited conversion to long chain n-3 acids for man

Flaxseed oil chemopreventive on colon cancer development [Chandradhar et al, 2005]

18:3 n-3 chemopreventive against colon cancer

Long chain n-3 fatty acids in food and animal feed [Christon, 2003]

Cardiovascular health could be enhanced with n-3 oils intake; long chain n-3 fatty acids regulate endothelial dysfunction

Linoleic and saturated acids do not inhibit endothelial activation

High 6/3(fish) ratio of 11-30 in N American and Israeli diets [Vos, 2005]

Possible contribution to heart disease, cancer, asthma, arthritis and depression and possibly increasing risk to infectious diseases; Israeli paradox

Israeli paradox: high 6 polyunsaturated and low saturated fat intake [Pierce & Dayton, 1971; Dubnov and Berry, 2003; Kark et al, 2003]

High linoleic acid (~12%) in Jewish diets; high CVD, hyperinsulinemia, metabolic syndrome X, obesity, and cancer; increase in cancer incidence in the Veterans Trial

6/3 Ratios in diets and CVD mortality [Vos & Cunnane, 2003; Wolfram 2003; Bulk et al, 2004]

High 3 and low CVD mortality, e.g. Greenland, Japan

High 6 cause of high CVD mortalitye.g. US, Northern Europe, Israel; risk of asthma, arthritis, depression and increased infection

Linoleic acid and DHA [Kalmijin et al, 1997; Demar et al, 2005]

3 fish oils protective unless polluted by mercury or other heavy metal

Linoleic acid prevents absorption of DHA in infants and is associated with cognitive impairment; risk of cataracts and dementia for adults.

Linoleic acid (18:2 n-6) versus DHA (22:6 n-3) [Buchner et al, 2002; Larsson, 2004; Hooper et al, 2006]

DHA may be associated with suppression of cancer; 3 fatty acids more effective in reducing mortality than statins.

Linoleic acid closely associated with mammary tumours and frequently associated with cancer but may protect (40% less) against prostate cancer.

Linoleic acid, 6 versus 3 fats [Kalmijin et al, 1997; Simopoulos & Cleland, 2003 ; Johnson & Schaefer, 2006; Arterburn et al, 2006]

3 marine fats provide cardiovascular, mental and visual health benefits

6 High linoleic acid intake associated with high risk of macular degeneration (a major cause of blindness), cognitive impairment and breast cancer

Polyunsaturated acids 18:2 and 18:3 [Lu et al 2005]

Risk of age-related lens opacity

Conjugated linoleic acid [Smedman et al 2005]

In vitro cytotoxicity and possible ‘anti-obesity’ action

Increased C-reactive protein

Risks from trans fats [Ascherio & Willett,1997; Lichtenstein et al, 1999; Mozaffarian et al, 2006]

Except for CLA, trans fats are among the worst in lipidemic behaviour

Possible link to the 93% rise in CVD; reduction of 2% trans fats with 18:2 can reduce CVD by 53%; possible cause of high incidences of macular degeneration

trans fats versus saturated fat [Fed Register, 2003]; similar effects of stearic acid diet compared to trans-fat diet [Turpeinen et al, 1998]

Labelling of trans fats required by 2006

trans fats lower the good HDL and interferes with cellular signalling pathways; trans fat associated with a 10-fold higher risk for CVD and possible detrimental effects to foetus/newborns

Myristic acid stimulate nitric oxide (NO) production [Zhu & Smart, 2005]

NO considered anti-atherogenic; palmitic is slightly less stimulatory

Myristic acid (14:0)-induced increase of plasma cholesterol may be offset by effects of NO



3

3.5

4

4.5

5

5.5

6

Tota

l-c, m

mol

/L

Lipid Profiles: Comparison of Palmolein with other Monounsaturated and Coconut Oils

Ratio Total-c/HDLTotal-c, mmol/L

Figure 7. Comparison of the lipidemic effects of palmolein, canola, extra virgin olive and coconut oils [Ng et al, 1991; Truswell et al, 1992; Truswell, 2004]

Palmolein and Other Major OilsIt may be pointed out that palmolein is probably the only widely available oil that provides the fatty acids required by the human body in terms of the fatty acid composition (Fig. 2). Studies on the lipidemic effects of palmolein and palm oil further consistently demonstrate that they have physical, chemical and nutritional properties much more like monounsaturated oils, the monounsaturated oleic acid being its major constituent fatty acid. In comparative studies of three monounsaturated oils (Fig. 7) it has been clearly demonstrated that the composition of sn-2 fatty acids will manifest their lipidemic properties, notably explaining why palmolein can be similar to (total-c) or better than (ratio of total-c/HDL) extra virgin olive oil [Choudhury et al, 1995; Sundram, 1997; Truswell et al, 1992; Truswell, 2004]. Total-c lowering is much more due to the effect of presence of linoleic acid (18:2) in the sn-2 position as can be seen in the comparison of palmolein with coconut oil which is almost devoid of 18:2 but has an excess of HDL-raising saturated fatty acids (Fig. 7).

Fig. 8 shows the expected blood lipid cholesterol-lowering effects with respect to 18:2 polyunsaturation [Ahrens et al, 1957; Hayes & Khosla, 1992; Truswell, 2004]. Noteworthy is the somewhat variable results obtained by various groups on same oils probably as a result of the complexity of dietary regimes where digestion/absorption can be affected by intakes of combination of fat types and other nutrients. Cocoa butter is also outstanding as a neutral cholesterolemic fat as it is naturally structured to have unsaturation at the sn-2 position in contrast to animal fats which are well known as hypercholesterolemic fats [Sanders et al 1999; Sanders et al, 2003; Tholstrup et al, 2003]. Apart

from this, stearic acid is known to be poorly absorbed compared to lauric and myristic acids, especially as calcium soaps. Fig. 9 is a chart which allows the comparison of a number of oils and fats for the sn-2 positional fatty acids. Apart from cocoa butter natural vegetable-based oils and fats can be highly structured as in palm, peanut and cocoa butter. Olive, palm, peanut and canola oil provide little of saturated fatty acids at the 2-position of the glycerides; they are in fact predominantly mononunsaturated and slight to moderately polyunsaturated. Fig. 10 which depicts antithrombotic effects of various oils and fats also provides complementary evidence that positional unsaturation of oils and fats is important [Hornstra and Kester, 1997]. As palmolein and palm oil provide glycerides of which the major oleic fatty acid and minor polyunsaturated acids are preferentially well absorbed, the spread of results for palm oil is suggestive of the presence of more anti-thrombotic minor components, presumably tocotrienols which may be somewhat variable as some may be lost in oxidation or during transport.

It is obvious that palmolein and oils from the oil palm have been emphasized because of their versatility in providing nutritional fats, heat stable fats, semi-solid fats without hydrogenation and trans-free fats [Juttelstad, 2004; deMan, 2000; Timms, 2005; Kita et al, 2005]. Modern processing methods of fractionation, blending, interesterification and enzymatic interesterification can provide the whole range of manufacturing fats, e.g. frying oils, margarines, bakery shortenings, puff-pastry fats, confectionery and specialty fats, and structured glycerides [Goh & Tang, 2005; Ong & Goh 2002; Warner & Gupta, 2005; Timms, 2005]. It is clear other oils such as extra virgin



olive, canola and high oleic sunflower oils can fill special culinary needs while the latter two oils can well have blends with various palm oils and fractions to provide the needs of the food processor [deMan, 2000; deMan & deMan, 2001; Braipson-Danthine et al, 2005].

Many high linoleic and linolenic oils will now need to blend with semisolid fats from palm, cottonseed and other minor sources or they will have to resort to total hydrogenation to avoid having trans fats [Petrauskaite et al, 1998]. The resulting solid stearic-rich fats will

need to be interesterified with liquid oils to provide for food processing needs. However the new unnatural glycerides that result from such treatments can give rise to potential problems not unlike the decades’ old problem of trans fats. Early studies have cautioned that stearic-rich fats can cause postprandial (immediately-after-eating) lipaemia which is a risk factor for CVD and indeed such fats are similar to trans fats in terms of platelet activation and endothelial PGI2 production (measures of thrombogenic properties) [Berry & Sanders, 2005; Buijsse et al, 2006].

Cholesterol and Polyunsaturation

1

10

100

-20 0 20 40 60 80

% Increase of Total Cholesterol

% P

olyu

nsat

urat

ion

SafflowerCornCottonseedPeanut

Canola

PalmoleinLardPalm High Oleic SunflowerOliveBeef

ButterCocoa butter

Coconut

POLYUNSATURATED

MONOUNSATURATED

S A T U R A T E D

Figure 8. Cholesterolemic effects and polyunsaturation (increase in total-c is relative to safflower oil) [Ahrens et al, 1957; Truswell, 2004]



Lins

eed

Soya

bean

Cor

n

Cot

tons

eed

Rap

esee

d

Can

ola

Pean

ut

Palm

Oil

Palm

olei

n

Oliv

e

Coc

oa b

utte

r

Shee

p (d

epot

)

Cat

tle (d

epot

)

Hyd

roge

nate

d So

ya*

Hum

an m

ilk

Cow

's m

ilk

Pig

(out

er b

ack)

Coc

onut

2-Saturated2-Monounsaturated

2-Polyunsaturated

0

10

20

30

40

50

60

70

80

90

100

%

2-Positional Fatty Acids

2-Saturated2-Monounsaturated2-Polyunsaturated

Figure 9. Distribution of 2-positional fatty acids in oils and fats [Goh et al, 2001; Ong & Goh, 2002]

RAT THROMBOSIS: 2-Positional Polyunsaturation (18:2)

versus Artery Occlusion Time[From data of Hornstra and Kester (1997)]

CB=cocoa butter, HSB=hydrogenated soy oil sample

1

10

100

10 100 1000

Artery Occlusion Time / hours

% 2

-Pos

ition

al P

olyu

nsat

urat

ion .

Olive

Palmolein

Palm Oil

Sunflower& Soya oils

Coconut & Hydrogenated Fats

Lard HSBCB

Figure 10. Rat thrombosis: effect of 2-positional polyunsaturation (CB=cocoa butter; HSB=hydrogenated soybean oil) [Hornstra and Kester, 1997]



Overview of Diet and FatsDietary recommendations have been controversial over the years but fortunately science and reason are slowly taking centre-stage [Goh, 2006; Table 1; Appendix 1]. For a long time the food pyramid has almost been a sacred cow but many changes have now been introduced. While it is accepted that no fixed diet is suitable for everybody, new recommendations have to take cognisance of on one hand the overwhelming successes in land-based agricultural foods and on the other hand the prevalence of obesity and diabetes/insulin resistance (“diabesity”). Previously oils and fats were restricted to the top of the food pyramid, they (nutritional fats) are now of equal value with low-glycaemic carbohydrates to provide for macronutrient energy [Reaven, 1995; Willet, 2001; Tarvani et al, 2003; Volek et al, 2004; McMillan-Price et al, 2006]. Present-day carbohydrate productions are as much a success story of modern agro-industry which effortlessly provides inexpensive processed and convenience foods, most of which tend to be easily digestible high-glycaemic carbohydrates and sugars. Other problems are in modern lifestyles (comfortable, sedentary, modern labour-saving facilities and little need for physical activity) and the widespread acceptance of convenience and fast-foods. Many N. American dietary recommendations have the potential of causing obesity because of the high carbohydrate recommendation while mistakenly just targeting for fat reduction. Before trans-fats were recommended for elimination, saturated fats have been savagely targeted for reduction. And for a long time CVD and obesity had been blamed on fat intake and measures such as fat reduction and switch to low-fat foods had not been effective. Apart from giving rise to the problems of obesity, insulin resistance and type II diabetes, there were also urgent problems such as CHD, cancer, macular degeneration and foetal damage that needed to be addressed, much of which are now attributed to over-consumption of trans and n-6 polyunsaturated fats.

Presently much more is also known of dietary oils and fats as the decades-old controversy on heart-diet-cholesterol hypothesis dissipated in the light of new findings. It is now clear that natural oils and fats (palm, cottonseed and peanut) with relatively more saturation than the traditional temperate oils (canola and soybean) are acceptable and are even preferred because their triglycerides, which are structured with high sn-2 unsaturation, render them more like monounsaturated oils (in the class of extra virgin oil). Further, trans fats from processing are to be eliminated while total hydrogenation has been cautioned as providing unnatural stearic-rich glycerides with questionable nutritional quality. As most oils and fats cannot fulfil the present hypothetical needs of high monounsaturation, moderate saturation, limited n-6 polyunsaturation and adequate amounts of essential n-3 fatty acids, use have to be made of the presently available oils of which the oil palm can provide a substantial proportion. Nutritional optimisation as well as food-processing requirements can thereby be fulfilled. This also takes into cognisance that other dietary components such as marine foods and vegetables and fruits also provide other much needed essential nutrients.

AbbreviationsCVD = cardiovascular disease; CHD = coronary heart disease, HDL-c = “good” high density lipoprotein cholesterol; ISSFAL = International Society for the Study of Fatty acids and Lipids; LDL-c = “bad” low density lipoprotein cholesterol; Lp(a) = a lipoprotein, high levels undesirable; MCT = medium chain triglycerides, containing mostly saturated C8-10 fatty acids; NO = nitric oxide, artery relaxing signalling molecule, lowers blood pressure; 3 or n-3 essential polyunsaturated fatty acid required by the body; RDI = recommended daily intake; TG = triglyceride or triacylglycerol, TG levels measure circulating neutral fat, an independent CVD risk factor; total-c = total cholesterol.



Appendix 1. Influence of dietary and environmental factors on health

Condition/environmental factors

Positive outcomes Negative outcomes

Smoking, stress and high blood pressure [worldheart.org]

Increase in cardiovascular disease (CVD) risk

Caloric excess and restriction [Heilbronn et al, 2006)

Caloric restriction increases longevity in animals; increases weight loss

Obesity and increase in associated risks (diabetes, hypertension and CVD) from excess food intake

Moderate (<33% energy) or low (<20% energy) fat diets but of similar caloric intake [McManus et al, 2001]

No discernable difference on mortality: caloric intake, not fat alone, is the cause of weight gain

Extreme fat restriction may be deleterious to cardiovascular health. Moderate fat diet shows lower risks to CVD than low fat diet.

Change from high to low fat (<20% energy) intake for women 50-79 years [Howard et al, 2006]

Statistically insignificant reduction in risk of breast cancer over the 8-year study

No significant change in obesity, diabetes, stroke, metabolic syndrome or colon cancer

Diets low (<20% energy) or very low (<9% energy) in fat and high in simple carbohydrate intake

High carbohydrate/low fat diet need to specify unprocessed whole grains and be coupled with intensive exercise

Increased risks of insulin resistance, type II diabetes, and CVD [Reaven, 1995; Willet, 2000; Noakes et al, 2006].

Low fat/low cholesterol diet ineffective [Corr and Oliver, 1997; Young, 2005]

Treatment necessary for vascular inflammation and to raise HDL-c

Reduction in fat and saturated fat and cholesterol intake is ineffective in reducing coronary events or total mortality.

Natural oils and fats are favoured in the new food pyramid [Willett, 2001]

Whole grains, natural vegetable oils and vegetables/fruits are favoured.

Excessive calories from processed grains of high glycaemic index not natural oils and fats are new dietary problems.

American heart association diet [Chahoud et al, 2004]

High fruit and vegetable diet favourable against CVD and cancer

High carbohydrate diet unsuitable for high-TG subjects and favours obesity

High fat or high saturated fat for healthy men [Poppit et al, 2006]

Saturated fat has no effect on ghrelin and leptin hormones which control food intake and adiposity

High fat diet may adversely affect leptin

Moderate and regular exercise [Thrall & Lip, 2005]

Reduced risk of CHD, stroke, diabetes, hip fracture and some kinds of cancer; increase in good HDL-c

Familial (genetic) hypercholesterolemia [Sijbrands et al, 2001]

Treatment available by statin drugs with anti-inflammatory properties

High risk of CVD mortality

Plant-based diet (high in fruits, vegetables, whole grains, nuts and legumes) rather than replacing saturated fats important [Gardner et al, 2005]

Lowered LDL-c, decreased risk of CVD and cancer; lower blood pressure; cholesterol lowering despite saturated fat and cholesterol diet; enhance effect of low fat diet

Diet with moderate and high (unpolluted) fish intake

Decreased risk of CVD A worldwide shortage in supply of fish and LC 3 polyunsaturated oils

Diet high in red meat [Wu et al, 2006]

Increased risk of CVD and colon/prostate cancer (from the food or its preparation)

Fast food diet (large portions, high fat of >40 % energy including trans fats and high glycaemic food and drinks)

Convenience foods encourage undesirable rapid eating habit and overeating

Increase risk of CVD, obesity and certain types of cancer; little concern to health of consumers until exposed



… continued Appendix 1. Influence of dietary and environmental factors on health

Condition/environmental factors

Positive outcomes Negative outcomes

Commercial monopolies of foods and processed foods

Need introduction of more difficultly digestible (or low glycaemic index) foods for the general population

Foods are inexpensive or tasty but may be of questionable nutritional quality and of limited variety; lesser availability and choice of nutritional foods

Low carbohydrate diet versus low fat but energy-matched diet [Tavani et al, 2003]

Satiety-induced calorie restriction occurred in low carbohydrate diet; low glycaemic index rather than low carbohydrate preferable

No significant difference in weight loss over the long term. Low carbohydrate diet may be unsuitable for people with coronary heart disease, gout or kidney disease.

High protein (Banting-Atkins) and low carbohydrate diet [Arora & McFarlane, 2004]

Low glycaemic index rather than low carbohydrate diet required; increased satiety and weight loss

Concerns of possible long term damage to kidneys and osteoporosis in high protein diet

Replacing high fat (45% to 25%) and saturated fat with carbohydrate (40% to 60%), [Abbasi et al, 2000]

82% increase in fasting TG, 133% increase in remnant lipoprotein, 250% increase in remnant TG and 11% lowering of good HDL-c

Comparison of hypo-energetic and isocaloric diets of very low carbohydrate (~10% energy)/high fat (60%) and high carbohydrate (55% energy; 25% fat)

More weight and fat loss in the very low carbohydrate diet; but over the longer term effects tend towards equality; high protein effective with anorexic effect [Wiegle et al, 2005]

Palm oil is antithrombotic [Hornstra and Kester , 1997]

Reduce atherosclerosis in animals; palmolein has structured glycerides with cholesterolemic effects similar to virgin olive oil

Palmitic acid in animal fats slightly cholesterol-raising compared to monounsaturated and polyunsaturated acids

Lowering saturated fat in average American diet from 15 to 6.1%, Ginsberg et al (1998) Delta 1 study

Reduced bad LDL-c by 11% Good HDL-c fell by 12% and bad Lp(a) rose by 17%

Low fat (15% energy) diet versus moderate fat for athletes [Horvath et al, 2000]

MCT with carbohydrates optimal for endurance

Low fat diet reduced endurance in tests

Serum cholesterol and mortality [Stemmermann et al 1991]

Lowest mortality found in men with moderately high cholesterol 4.65-6.18 mmol/L

Colon and lung cancers strongly correlate with low serum cholesterol

Nuts in diets [Albert et al, 2002; Kris-Etherton et al, 1999]

Arginine (precursor to NO) is recognised to be important blood vessel relaxing factor; other benefits are from Mg and 3 polyunsaturated acids

DisclaimerInformation provided is from authoritative sources but this is not intended to substitute advice from medical and health care professionals. Problems related to health, diet and ailments should normally be referred to medical authorities as body weight or lack of it can be symptoms of problems which may need urgent medical attention.

ReferencesAbbasi F, McLaughlin T, Lamendola C, Kim HS,

Tanaka A, Wang T, Nakajima K, and Reaven GM (2000) High-carbohydrate diets, triglyceride-rich lipoproteins and coronary heart disease risk. Amer Jour Cardiol 85(1): 45-8.

Ahrens EH, Hirsh J, Insull W, Tsaltas TF, Blomstrand R, Peterson ML (1957) The influence of dietary fats on serum lipid levels in man. Lancet May, 943-53.



Albert CM, Gaziano JM, Willett WC, Manson JE (2002) Nut consumption and decreased risk of sudden cardiac death in the Physicians’ Health Study. Arch Intern Med 162(12): 1382-87.

Aoe S, Yamamura J, Matsuyama H, Hase M, Shiota M, Miura S (1997) The positional distribution of dioleoyl-plamitoyl glycerol influences lymph chylomicron transport, composition and size in rats. J Nutr 127(7): 1269-73.

Arora S and McFarlane SI (2004) Review on "Atkins Diabetes Revolution: The Groundbreaking Approach to Preventing and Controlling Type 2 Diabetes" by Vernon MC and Eberstein JA. Nutr Metab 1: 14.

Arterburn LM, Hall EB, Oken H (2006) Distribution, interconversion, and dose response of n-3 fatty acids in humans. Am J Clin Nutr 83(6): S1467-76

Ascherio A, Willett WC (1997) Health effects of trans fatty acids. Am J Clin Nutr 66: 1006S-1010S.

Berry SEE and Sanders TAB (2005) Influence of triacylglycerol structure of stearic acid-rich fats on postprandial lipaemia. Proc Nutr Soc 64: 205-12.

Braipson-Danthine S, Gibon V and Deroanne C (2005) Physicochemical characteristics of ternary fat blends involving low-erucic rapeseed oil. Eur J Lipid Sci Technol 107: 627-33.

Buchner HC, Hengstler P, Schindler C, Meier G (2002) n-3 Polyunsaturated fatty acids in coronary heart disease: a meta-analysis of randomized controlled trials. Am J Med 112: 298-304.

Bulk E, Chung M, Lichtenstein A, Chew P, Kupelnick B, Lawrence A, De Vine D, Lau J (2004) Effects of omega-3 fatty acids on cardiovascular risk factors and intermediate markers of cardiovascular disease. AHR Q Publication No. 04-E010-2, Agency for Healthcare Research and Quality, US Department of Health and Human Services, Rockville, MD.

Buijsse B, Feskens EJM, Kok FJ, Kromhout D (2006) Cocoa intake, blood pressure, and cardiovascular mortality. The Zutphen elderly study. Arch Intern Med 166(4): 411-17.

Burdge G (2004) -Linolenic acid metabolism in men and women: nutritional and biological implications, Curr Opin Clin Nutr & Metabol Care 7(2): 137-44.

Burdge GC and Calder PC (2005) Conversion of -linolenic acid to longer-chain polyunsaturated fatty acids in human adults. Reprod Nutr Dev 45: 581-97.

Carnielli VP, Luijendijk IHT, van Goudoever JB, Sulkers EJ, Boeriage AA, Degenhart HJ, Sauer PJJ (1996) Structural position and amount of palmitic acid in infant formulas: effects on fat, fatty acid, and mineral balance. Jour Pediatric Gastroent & Nutr 23(5): 553-60.

Chahoud G, Aude YW, Mehta JL (2004) Dietary recommendations in the prevention and treatment of coronary artery disease: Do we have the ideal diet yet? Am J Cardiol 94: 1260-67.

Chandradhar D, Natarajan K, Matthees DP (2005) Chemopreventive effects of dietary flaxseed oil on

colon tumor development. Nutrition and Cancer 51(1): 52-58.

Christon RA (2003) Mechanisms of action of dietary fatty acids in regulating the activation of vascular endothelial cells during atherogenesis. Nutr Rev 61(8): 272-79.

Choudhury N, Tan L, Truswell AS (1995) Comparison of palmolein and olive oil: effects on plasma lipids and vitamin E in young adults. Am J Clin Nutr 61: 1043-51.

Choudhury N, Truswell AS, McNeil Y (1997) Comparison of plasma lipids and vitamin E in young and middle aged subjects on potato crisps fried in palm olein and highly oleic sunflower oil. Ann Nutr & Metab 41: 137-48.

Corr LA, Oliver MF (1997) The low fat/low cholesterol diet is ineffective. Eur Heart Jour 18: 18-22.

deMan JM (2000) Use of palm stearin as a component of interesterified blends. SCI Lecture Papers Series, SCI. www.soci.org

deMan JM and deMan L (2001) Polymorphism and texture of fats. In: Widlak N, Hartel R and Narine S (eds), Crystallization and Solidification properties of Lipids, AOCS Press, Champaign, IL, pp 225-35.

Demar JC jr, Ma K, Chang L, Bell JM, Rapoport SI (2005) -Linolenic acid does not contribute appreciably to docosahexaenoic acid within brain phospholipids of adult rats fed a diet enriched in docosahexaenoic acid. Jour Neurochem 94 (4): 1063-76

Dubnov G, Berry EM (2003) Omega-6/omega-3 essential fatty acid ratio: the Israeli paradox. In: Simopoulos AP, Cleland LG (eds): Omega-6/omega-3 essential fatty acid ratio: the scientific evidence. World Rev Nutr Diet, Basel, Karger; vol 92, pp 81-91

Estruch R, Martinez-Gonzalez MA, Corella D, Salas-Salvado J, Ruiz-Gutierrez V, Covas MI, Fiol M, Gomez-Gracia E, Lopez-Sabater MC, Vinyoles E, Aros F, Conde M, Lahoz C, Lapetra J, Saez G, Ros E, and PREDIMED Study Investigators (2006) Effects of a Mediterranean-style diet on cardiovascular risk factors: A randomized trial. Ann Inern Med 145(1): 1-11.

Fallon S, Enig M and Sanda B (2005) Comments to the 2005 Dietary Guidelines Advisory Committee Report, Weston A Price Foundation, Washington DC, 57pp.

Federal Register (2003) Food labelling: trans fatty acids in nutrition labelings; consumer research to consider nutrient content and health claims. Federal Register 68(133): 41433-506.

Felton CV, Crook D, Davies MJ, Oliver MF (1994) Dietary polyunsaturated fatty acids and composition of human aortic plaques. Lancet 344: 1195–6.

Gardner CD, Coulston A, Chatterjee MS, Rigby A, Spiller G, farquhar JW (2005) The effect of a plant-based diet on plasma lipids in hypercholesterolemic


http://www.soci.org/


adults. A randomized trial. Ann Intern Med 142(9): 725-33.

Garg ML, Wood LG, Singh H, Moughan PJ (2006) Means of delivering recommended levels of long chain n-3 polyunsaturated fatty acids in human diets. Jour Food Sci 71(5): R66.

Gee PT and Goh SH (2006) Functional minor components in oils and fats: update 2006. Malaysian Oil Science and Technology 15(1): 7-14.

Giltay EJ, Gooren LJ, Toorians AW, Katan MB, Zock PL (2004) Docosahexaenoic acid concentrations are higher in women than in men because of estrogenic effects. Am J Clin Nutr 80(5); 1167-74.

Ginsberg HN, Kris-Etherton P, Dennis B, Elmer PJ, Ershow A, Lefevre M, Pearson T, Roheim P, Ramakrishnan R, Reed R, Stewart K, Stewart P, Phillips K, Anderson N (1998) Effects of reducing saturated fatty acids on plasma lipids and lipoproteins in healthy subjects: the DELTA study, protocol 1. Arterioscler Throm Vasc Biol 18:441-49.

Goh SH (1999) Cholesterol. Malaysian Oil Science and Technology 8(2): 58-59.

Goh SH (2001) Cholesterol Update 2001. Malaysian Oil Science and Technology 10(2): 133-41.

Goh SH, Hew NF, Khor HT (2004) Cholesterol and beyond. Malaysian Oil Science and Technology 13(1): 58-64.

Goh SH, Tang TS (2005) Healthy oils and fats sans-trans for the present millennium. Malaysian Oil Science & Technology 14(2): 33-39.

Goh SH (2006) Oils and fats in nutrition and health: 1. General considerations. Malaysian Oil Science & Technology 15(1): 15-21.

Gunstone F (2005) Fatty acid production for human consumption. INFORM 16(12): 736-7.

Hayes KC, Khosla P (1992). Dietary fatty acid thresholds and cholesterolemia. FASEB J 6: 2600-07.

Heilbronn LK, de Jonge L, Frisard MI, DeLany JP, Larson-Meyer DE, Rood J, Nguyen T, Martin CK, Volaufova J, Most MM, Greenway FL, Smith SR, Deutsch WA, Williamson DA, Ravussin E (2006). Effect of 6-month calorie restriction biomarkers of longevity, metabolic adaptation, and oxidative stress in overweight individuals. JAMA 295(13): 1539-48

Hornstra G and Kester AND (1997) Effect of the dietary fat type on arterial thrombosis tendency: systematic studies with a rat model. Atherosclerosis 131: 25-33.

Horvath PJ, Eagen CK, Ryer-Calvin SD, Pendergast DR (2000) The effects of varying dietary fat on the nutrient intake in male and female runners. J Amer Coll Nutr 19(1): 42-51.

Hooper L, Thompson RL, Harrison RA, Summerbell CD, Ness AR, Moore HJ, Worthington HV, Durrington PN, Higgins JP, Capps NE, Riemersma RA, Ebrahim SB, Smithe GD (2006) Risks and benefits of omega 3 fats for mortality, cardiovascular

disease, and cancer: systematic review. BMJ 332: 752-60.

Howard BV, van Horn L, Hsia J, Manson JE, Stefanick ML, Wassertheil-Smoller S, Kuller LH, LaCroix AZ, Langer RD, Lasser NL, Lewis CE, Limacher MC, Margolis KL, Mysiw WJ, Ockene JK, Parker LM, Perri MG, Phillips L, Prentice RL, Robbins J, Rossouw JE, Sarto GE, Schatz IJ, Snetselaar LG, Stevens VJ, Tinker LF, Trevisan M, Vitolins MZ, Anderson GL, Assaf AR, Bassford T, Beresford SAA, Black HR, Brunner RL, Bryski RG, Caan B, Chlebowski RT, Gass M, Granek I, Greenland P, Hays J, Heber D, Heiss G, Hendrix SL, Hubbel FA, Johnson KC, Kotchen JM (2006) Low-fat dietary pattern and risk of cardiovascular disease. JAMA 295(6): 655-66.

Hu FB, Stampfer MJ, Manson JE, Ascherio A, Colditz GA, Speizer FE, Hennekens CH, Willett WC (1999) Dietary saturated fats and their food sources in relation to the risk of coronary heart disease in women. Am J Clin Nut 70(6): 1001-8.

Hu FB, Manson JE and Willett WC (2001) Types of dietary fat and risk of coronary heart disease: a critical review. Jour Amer Coll Nutr 20(1): 5-19.

Hu FB, Willett WC (2002). Optimal diets for prevention of coronary heart disease JAMA 288: 2569-78

Innis SM, Dyer RA, Lien EL (1997) Formula containing randomized fats with palmitic acid (16:0) in the 2-position increases 16:0 in the 2-position of plasma and chylomicron triglycerides in formula-fed piglets to levels approaching those of piglets fed sow’s milk. Jour Nutr 127(7): 1362-70

Jenkins DJA, Kendall CWC, Marchie A (2005) Diet and cholesterol reduction. Ann Intern Med 142:793-4.

Johnson EJ and Schaefer EJ (2006) Potential role of dietary n-3 fatty acids in the prevention of dementia and macular degeneration. Am J Clin Nutr 83(6): S1494-98.

Juttelstad A (2004). trans Fats: Status and solutions, the marketing of trans fat-free foods, Food Tech 58(1): 20-31

Kalmijin S, Feskins EJM, Launer LJ, Kromhout D (1997). Polyunsaturated fatty acids, antioxidants and cognitive function in very old men. Am J Epidemiol 145: 33-41.

Kang MJ, Shin MS, Park JN, Lee SS (2005) The effects of polyunsaturated:saturated fatty acids ratios and peroxidisability index values of dietary fats on serum lipid profiles and hepatic enzyme activities in rats. Br J Nutr 94(4): 526-32.

Kark JD, Kaufmann NA, Binka F, Goldberger N, Berry EM (2003). Adipose tissue n-6 fatty acids and acute myocardial infarction in a population consuming a diet high in polyunsaturated fatty acids. Am J Clin Nutr 77: 796-802.

Kita A, Lisiska G and Powolny M (2005) The influence of frying medium degradation on fat



uptake and texture of French fries, Jour Sci Food & Agric 85(7): 1113-18

Kotte TE (2003) What is the optimal diet for cardiovascular health? BMJ 327: E31-E33

Kris-Etherton PM, Yu-Poth S, Sabate J, Ratcliffe HE, Zhao G, Etherton TD (1999) Nuts and their bioactive constituents: Effects on serum lipids and other factors that affect disease risk. Amer J Clin Nutr 70(3S): 504S-511S.

Kritchevsky D, Tepper SA, Chen SC, Meijer GW (1996) Influence of triglyceride structure on experimental atherosclerosis in rabbits. FASEB J 10: A187.

Kritchevsky D (2000) Impact of natural carotene and tocotrienol-rich red palm oil on human nutrition and health. Food and Nutr Bull 21(2): 182-88.

Larsson SC, Kumlin M, Ingelman-Sundberg M, Wolk A (2004). Dietary long-chain n-3 fatty acids for the prevention of cancer: a review of potential mechanisms. Am J Clin Nutr 79(6): 935-45.

Lefevre M, Champagne CM, Tulley RT, Rood JC and Most MM (2005). Individual variability in cardiovascular disease risk factor responses to low-fat and low-saturated-fat diets in men: body mass index, adiposity, and insulin resistance predict changes in LDL cholesterol, Amer Jour Clin Nutr 82(5): 957-63.

Lichtenstein AH, Ausman LM, Jalbert SM, Schafer EJ (1999). Effects of different forms of dietary hydrogenated fats on serum lipoprotein cholesterol levels. N Engl J Med 340: 1933-40.

Lien EL, Boyle FG, Yuhas R, Tomarelli RM, Quinlan P (1997). Fatty acid absorption in rats. J Pediatr Gastroent & Nutr 25(2): 167-74.

Linderborg KM and Kallio HPT (2005). Triacylglycerol fatty acid positional distribution and postprandial lipid metabolism. Food Rev Internat 21(3): 331-55.

Lu M, Taylor A, Lee TC jr, Rogers G, Hankinson SE, Willett WC, Jacques PF (2005). Dietary fat intake and early age-related lens opacities. Am J Clin Nutr 81(4): 773-79.

Lucas A, Quinlan P, Abrams S, Ryan S, Meah S, Lucas PJ (1997). Randomised controlled trial of a synthetic triglyceride milk formula for preterm infants. Arch Dis Child Fetal Neonatal Ed 77: F178-184.

McMillan-Price J, Petocz P, Atkinson F, O’neill K, Samman S, Steinbeck K, Caterson I and Brand-Miller J (2006) A randomized controlled trial of a moderate-fat, low-energy diet for weight loss in overweight adults: One-year follow-up of a randomized trial. Arch Intern Med 166: 1466-75.

McManus K, Antinoro L, Sacks F (2001) A randomized controlled trial of a moderate-fat, low-energy diet for weight loss in overweight adults. Int J Obes Relat Metab Disord 25(10): 1503-11.

Mohd Suria Affandi Y, Noor Uda Habi MD, Kamal Azmi H and Rozi MP (1996) Trans-free margarine

formulation, PORIM Technical Information Series 55, May 1996.

Mozaffarian D, Katan MB, Ascherio A, Stampfer MJ, Willett WC (2006) trans Fatty acids and cardiovascular disease. N Engl J Med 354(15): 1601-13.

Neoh SB and Goh SH (2003) A review of the digestion and absorption of oils and fats in feeds for poultry and swine. Malaysian Oil Science and Technology 12(1): 60-63.

Ng TK, Hassan K, Lim JB, Lye MS, Ishak R (1991) Nonhypercholesterolemic effects of a palm-oil diet in Malaysian volunteers. Am J Clin Nutr 53: 1015S-1020S.

Noakes M, Clifton P (2005) The CSIRO total wellbeing diet. CSIRO, 212 pp.

Noakes M, Foster PR, Keogh JB, James AP, Mamo JC, Clifton PM (2006) Comparison of isocaloric very low carbohydrate/high saturated fat and high carbohydrate/low saturated fat diets on body compostion and cardiovascular risk. Nutr & Metab 3: 7.

Ong ASH and Goh SH (2002). Palm oil: a healthful and cost-effective dietary component. Food and Nutr Bull 23: 11-22.

Ordovas JM (2005). Diet-Heart hypothesis: will diversity bring reconciliation? Amer Jour Clin Nutr 82(5): 919-20.

Pamploma R, Portero-Otin M, riba D, Ruiz C, Prat J, Bellmuni MJ, Barja G (1998). Mitochondiral membrane peroxidizability index is inversely related to maximum life span in mammals. Jour Lipid Res 39:1989-94.

Petrauskaite V, de Greyt W, Kellens M, Huyghebaert A (1998) Physical and chemical properties of trans-free fats produced by chemical interesterification of vegetable oil blends. J Am Oil Chem 75: 489-93.

Pierce ML and Dayton S (1971). Incidence of cancer in men on a diet high in polyunsaturated fat. The Veterans Trial. Lancet Mar 6: 464-7.

Poppitt SD, Leahy1 FE, Keogh1 GF, Wang Y, Mulvey TB, Stojkovic M, Chan YK, Choong YS, McArdle BH and Cooper GJS (2006). Effect of high-fat meals and fatty acid saturation on postprandial levels of the hormones ghrelin and leptin. European Journal of Clinical Nutrition 60: 77–84.

Reaven GM (1995) Pathophysiology of insulin resistance in human disease. Physiol Rev 75: 473-86.

Rings EHHM, Minnich DM, Vonk RJ, Stellaard F, Fetter WPF, Verkade HJ (2002) Functional development of fat absorption in term and preterm neonates strongly correlates with ability to absorb long-chain fatty acids from intestinal lumen. Pediatric Research 51: 57-63.

Salmi YS (2004). Trans-free palm-based chocolate spread, MPOB Information Series 253, June 2004.

Sanders TA, de Grassi T, Miller GJ, Humphries SE (1999) Dietary oleic and palmitic acids and



postprandial factor VII in middle-aged men heterozygous and homozygous for factor VII R353Q polymorphism. Am J Clin Nutr 69: 220-25.

Sanders TA (2003). High- versus low-fat diets in human diseases. Curr Opin Clin Nutr Metab Care 6: 151-6.

Sanders TAB, Berry SEE, Miller GJ (2003) Influence of triacylglycerol structure on the postrandial response to factor VII to stearic acid-rich fats. Am J Clin Nutr 77(4): 777-82.

Schmelzle H, Wirth S, Skopnik H, Radke M, Knol J (2003) Randomized double-blind study of the nutritional efficacy and bifidogenicity of a new infant formula containing partially hydrolysed protein, a high [beta]-plamitic acid level, and nondigestible oligosaccharides. J Pediatr Gastroent & Nutr 36(3): 342-51.

Sijbrands EJG, Westendorp RGJ, Defesche JC, de Meier PHEM, Smelt AHM, Kastelein JJP (2001) Mortality over two centuries in large pedigree with familial hypercholesterolaemia: family tree mortality study. BMJ 322: 1019-23.

Simopoulos AP, Cleland LG (eds) (2003) Omega-5/omega-3 essential fatty acid ratio: the scientific evidence. World Review of Nutrition and Dietetics.

Smedman A, Basu S, Jovinge S, Fredrikson GN, Vessby B (2005) Conjugated linoleic acid increased C-reactive protein in human subjects. Br J Nutr 94: 791-5.

Stemmermann GN, Chyou PH, Kagan A, Nomura AM, Yano K (1991) Serum cholesterol and mortality among Japanese-American men. The Honolulu (Hawaii) Heart Program. Arch Intern Med 151(5).

Stender S and Dyerberg J (2003) The influence of trans fatty acids on health. The Danish Nutrition Council Publ. no. 34, 4th ed.

Sulzle AHirche F, and Eder K (2004) Thermally Oxidized Dietary Fat Upregulates the Expression of Target Genes of PPAR{alpha} in Rat Liver, Jour Nutr 134(6): 1375 - 1383.

Sundram K (1997) Modulation of human lipids and lipoproteins by dietary palm oil and palm olein: a review Asia Pacific J Clin Nutr 6(1): 12-16.

Tavani A, Bosetti C, Negri E, Augustin LS, Jenkins DJA, La Vecchia C (2003). Carbohydrates, dietary glycaemic load and glycaemic index, and risk of acute myocardial infarction. Heart 89: 722-28.

Tavani A, Bosetti C, Negri E, Augustin LS, Jenkins DJA, La Vecchia C (2003) Carbohydrates, dietary glycaemic load and glycaemic index, and risk of acute myocardial infarction. Heart 89: 722-28.

Thijssen MA and Mensink RP (2005) Amer Jour Clin Nutr 82(3): 510-16].

Thrall G and Lip GYH (2005) Exercise and the prothrombotic state. Arterioscl Throm Vasc Biol 25: 265

Timms RE (2005) Fractional crystallisation: The fat modification process of the 21st century. Malaysian Oil Sci & Tech 14(1): 1-8.

Truswell AS, Cuddly N, Roberts DCK (1992) Double blind comparison of plasma lipids in healthy subjects eating potato crisps fried in palmolein or canola oil. Nutr Res 12: S43-S42.

Truswell AS (2004) Palm oil: The Cholesterol Dimension, Malaysian Oil Sci & Tech 13(1): 1-10.

Turpeinen AM, Wubert J, Aro A, Lorenz R, Mutanen M (1998) Similar effects of diets rich in stearic acid or trans-fatty acids on platelet function and endothelial prostacyclin production in humans. Arter, Throm, & Vasc Biol 18:316-22.

van Jaarsveld PJ, Smuts CM and Benade AJS (2002) Effect of palmolein oil in a moderate-fat diet on plasma lipoprotein profile and aortic atherosclerosis in non-human primates, Asia Pac Jour Clin Nutr 11: S424.

Volek JS, Sharman MJ, Gómez AL, Judelson DA, Rubin MR, Watson G, SokmenB, Silvestre R, French DN and Kraemer WJ (2004) Comparison of energy-restricted very low-carbohydrate and low-fat diets on weight loss and body composition in overweight men and women. Nutr Metab (Lond) 1(1): 1-13.

von Schacky C (2004) Omega-3 fatty acids and cardiovascular disease. Curr Opin Clin Nutr Metab Care 7: 131-36.

Vos E and Cunane SC (2003) -Linolenic acid, linoleic acid, coronary artery disease, and overall mortality. Am J Clin Nutr 77(2): 521-22.

Vos E (2005). Modified Mediterranean diet and survival. Key confounder was missed. BMJ 330: 1329.

Warensjo E, Jansson JH, Berglund L, Boman K, Ahren B, Weinehall L, Lindahl B, Hallmans G, Vessby B (2004) Estimated intake of mild fat is negatively associated with cardiovascular risk factors and does not increase the risk of a first acute myocardial infarction. A prospective case-control study. Br J Nutr 91(4): 635-42.

Warner KA and Gupta M (2005). Potato chip quality and frying oil stability of high oleic acid soybean oil, Jour Food Sci 70(6): 395-400.

Weinberg SL (2004). The diet-heart hypothesis: a critique, Jour Amer Coll Cardiol 43: 731-3.

Wheland J and Rust C (2006) Innovative dietary sources of n-3 fatty acids. Ann Rev Nutr 26: 75-103.

Wiegle DS, Breen PA, Matthys CC, Callahan HS, Meeuws KE, Burden VR, Purnell JQ (2005) A high-protein diet induces sustained reductions in appetite, ad libitum caloric intake, and body weight despite compensatory changes in diurnal plasma leptin and ghrelin concentrations Amer Jour Clin Nutr 82(1): 41-48.

Willett WC (2000) Will high-carbohydrate/low-fat diets reduce the risk of coronary heart disease? Proc Soc Exp Biol Med 225: 187-90.



Willett WC (2001) Eat, Drink and Be Healthy. The Harvard School of Public Health.

Wolfram G (2003) Dietary fatty acids and coronary heart disease. Eur J Med Res 8(8): 321-4.

Wu K, Giovannucci E, Byrne C, Platz EA, Fuchs C, Willett WC, Sinha R (2006) Meat mutagens and risk of distal colon adenoma in a cohort US men. Cancer Epidemiology Biomarkers and Prevention 15: 1221-35

www.religion-cults.com/diet/calories.htm USDA data.

www.worldheart.org World Heart Federation: CVD facts and risk factors [accessed July 2006]

Young IS (2005) Lipids for psychiatrists – an overview. Jour Psychopharm 19(6): 55-75.

Zhu W, Smart EJ (2005) Myristic acid stimulates endothelial nitric-oxide synthase in a CD36- and an AMP Kinase-dependent Manner. J Biol Chem 280 (33): 29543-50.

[Received and edited in Nov. 2006]


http://www.worldheart.org/

http://www.religion-cults.com/diet/calories.htm

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