OMEGA-3 FATTY ACIDS AND METABOLIC

SYNDROME Josh Nooner, BS, CSCS

NSCI – 69604/6/16

OBJECTIVES1. Review the definition, diagnostic criteria, and prevalence of

metabolic syndrome2. Explore n-3 PUFAs and how they relate to metabolic syndrome

(MetS)3. Discuss the findings from early studies 4. Summarize the results, strengths and weaknesses, and

recommendations of the supporting and main articles5. Give recommendations for future research 6. Provide a take home message

Family with Mets

Me Mom Dad

GrandMother Grand

Father

Uncle

GrandMother

Great Uncle

Aunt Uncle

Great Aunt

Cousin

• 6 on my mother’s side • 5 on my father’s side

11 total family members with MetS

10% of children have MetS

34% of American adults have MetS according to the AHA

50% of adults >50 yrs old have MetS

Individuals with MetS are 5x more likely to develop diabetes and 2x more likely to develop CVD

WHAT IS METABOLIC SYNDROME? Definition: A cluster of biochemical and physiological

abnormalities associated with the development of cardiovascular disease and type 2 diabetes

Diagnostic Criteria: The patient must present with 3 of the 5 biochemical/physiological complicationso Waist circumference and HDL differ between genders

ROLE OF N-3 PUFASN-3 PUFAs shown to modulate- Inflammation- Oxidative stress- Obesity- Endothelial dysfunction- Hypertriglyceridemia

Exert slight effects on- Hypertension- LDL size - Insulin sensitivity

OMEGA-3 FATTY ACIDS ALA, EPA, & DHA

ALA food sources: Vegetable oils, nuts, seeds

EPA/DHA food sources: marine fish, fish oil

Interconversion is very limited

ESSENTIALITY AND N-6/N-3 RATIO N-3 PUFAs are essential nutrients

Humans lack desaturase enzymes needed to synthesize N-3’s de novo

N-3 needs depend on N-6 intake

N-3 and N-6 share a similar metabolic pathway and compete for desaturase and elongase enzymes

The higher the n-6 intake, the more n-3 will be required to see positive effects of intervention

Baseline levels vary by geographical location

DOSAGE AND SIDE EFFECTS N-3 recommendations depend on disease progression

Most interventional studies use between 1-2g/day

The AI has been set at 1.6g/day for men and 1.1g/day for women

Very few and minimal negative effects: fishy taste, fish burps, GI disturbance, steatorrhea, slight LDL-C increase, potential for increased bleeding risk, potential for decreased immunity, possible environmental contamination

FDA ruled that intakes up to 3 g/day are Generally Recognized As Safe (GRAS) and are unlikely to result in bleeding

EARLY STUDIES ON METS ABNORMALITIES

1978: Dyerberg reported that higher EPA levels are protective against thrombosis and atherosclerosis

1979: Dyerberg reported Greenland Eskimos have lower incidence of thrombotic disorders and heart attack due to substitution of arachidonic acid with EPA

1980: Hirai reported higher EPA/AA ratio in a Japanese fishing village with lower incidence of cardiovascular and inflammatory diseases

1980: Kromann reported lower incidence of inflammatory disorders in Greenland Eskimos with high fish intake

1983: Prickett reported EPA protected mice from autoimmune nephritis by reducing inflammation

1985: Kromhout et al reported an inverse relation between fish consumption and 20-year mortality from coronary heart disease

EARLY STUDIES CONT.1987: Joel reported that fish oil supplementation resulted in alleviation of active rheumatoid arthritis

1991: Dolecek reported an inverse relation between dietary PUFA intake and all cardiovascular diseases

1991: Stenson reported fish oil supplementation results in significant improvements in ulcerative colitis

1997: Daviglus et al reported an inverse relation to fish consumption and death from myocardial infarction

2002: Hu et al reported higher consumption of fish and N-3 PUFAs is associated with a lower risk of CHD death

N-3/N-6 METABOLISM AND INFLAMMATION

N-6 fatty acids N-3 fatty acids

Arachidonic Acid Eicosapentaenoic Acid

Series 2 Prostaglandins Series 3 ProstaglandinsSeries 2 Thromboxanes Series 3 ThromboxanesSeries 4 Leukotrienes Series 5 Leukotrienes

Pro-inflammatory Anti-inflammatory

• Mechanism to reduce inflammation/oxidative stress/endothelial dysfunction

PUFA REGULATION OF GENE EXPRESSION• Mechanism to reduce hypertriglyceridemia & obesity / increase HDL

Protein Effect of n-3 PUFA

SREBP1 (sterol regulatory element binding protein)

Inhibition(Decreases lipogenic genes)

Sp1(Stimulatory protein 1)

Inhibition(Decreases lipogenic genes)

NF-Y (Nuclear factor Y)

Inhibition(Decreases lipogenic genes)

PPAR (Peroxisome proliferator-activated receptor response element)

Activation(Increases lipolytic genes)

CETP (Cholesterol ester transfer protein)

Inhibition(Increases HDL cholesterol)

Supporting Article 1

Metabolic Syndrome: Effects of n-3 PUFAs on a Model of Dyslipidemia, Insulin Resistance, and Adiposity

Lombardo, Y. B., Hein, G., & Chicco, A. (2007). Metabolic Syndrome: Effects of n-3 PUFAs on a Model of Dyslipidemia, Insulin Resistance, and Adiposity Lipids, 42, 427-437.

SUPPORTING ARTICLE 1: LOMBARDO ET AL

Purpose: Investigate the effectiveness of fish oil to reverse dyslipidemia, insulin resistance, and adiposity induced by long term feeding of a sucrose-rich diet

Methods1. Wistar rats randomly divided into a control group(N=12) or experimental group (N=12)o Experimental: Sucrose rich diet (62.5% sucrose, 17% casein, 8% corn oil, 7.5% cellulose, 3.5% salt mixture, 1.5% vitamin

mixture) o Control (CD): Isocaloric diet except sucrose was replaced by starch

2. After 6 months, the experimental group randomly divided into two subgroups. o Subgroup 1(SRD): Continued the sucrose rick diet up to 8 monthso Subgroup 2 (SRD + FO): Source of fat was replaced with fish oil for the remaining two months o Control Diet (CD): maintained control diet throughout the 8 month period- Diets were isoenergetic and provided ad libitum

3. Blood samples were taken to test for FFA and glucose concentrationsLiver, pancreas, gastrocnemius, and adipocyte tissues were assayed for lipogenic and glycogenic enzyme activity

Statistical Analysis: 1-way ANOVA and Newman Keul’s test

RESULTS

• Fish oil significantly reduced plasma triglyceride, FFA, and glucose concentrations

• Lipogenic enzymes are significantly reduced in the FO group

• Lipolytic enzymes are significantly increased in the FO group

• Triglycerides and triglyceride secretion rate significantly reduced in the FO group

• Insulin sensitivity restored in FO group

• FO significantly reduced fat concentration, cell volume, and relative weight in both epididymal and retroperitoneal areas

• LPL levels significantly higher in SRD group

• FO completely normalized glucose stimulated insulin secretion in SRD fed rats

• In pancreatic islet cells, triglyceride levels were significantly lower in the FO group which allowed for a normalization of PDHc activity

STRENGTHS/WEAKNESSES

Strengths• Long study period (8 months)• Multiple analytical methods (blood samples,

tissue assays from multiple sites, different stimulators for insulin secretion response)

• Randomization • Confounding variables tightly controlled for

Weaknesses• Small sample size (N=12)• Animal study can’t be generalized to humans

Supporting article 2

Omega-3 fatty acid supplements improve the cardiovascular risk profile of subjects with metabolic syndrome, including markers of inflammation and auto-immunity

Ebrahimi, M., Ghayour-Mobarhan, M., Rezaiean, S., Hoseini, M., Parizade, S.M., Farhoudi, F., & Hosseininezhad, S.J. (2009). Omega-3 fatty acid supplements improve the cardiovascular risk profile of subjects with metabolic syndrome, including markers of inflammation and auto-immunity Acta Cardiologica, 64(3), 321-327.

SUPPORTING ARTICLE 2: EBRAHIMI ET AL Purpose: To investigate the effect of n-3 PUFAs on established cardiovascular

risk factors including anthropometric and biochemical parameters and heat shock protein (Hsp) 27 antibody titers in subjects with metabolic syndrome

Methods: Subjects were randomly assigned to either a control group (N=60)or experimental group (N=60) for the 6 month test period

o Control group: Maintained normal diet throughout the 6 monthso Experimental group: Normal diet plus daily fish oil capsules (1g/day)

- Fatty acid capsules contained 180mg EPA + 120mg DHA - Compliance monitored by weekly visits and counting capsules

o Anthropometric and lab data were collected at the end of the trial

Statistical Analysis: Kolmogorov-Smirnov test, ANOVA, Fisher’s exact test, chi square test

RESULTS

• Fish oil significantly reduced weight, BMI, and systolic blood pressure

• The fish oil group significantly lowered total cholesterol, LDL cholesterol, and triglycerides

• Significant reduction of inflammatory markers Hsp 27 and CRP

STRENGTHS/WEAKNESSESStrengths• Length of study (6 months)• Sample size (120)• Compliance was monitored

Weaknesses• Many subjects were taking anti-hypertensive and

anti-diabetic medication• Effects may have been due to other dietary factors • Not double-blind or placebo controlled• Effects in the intervention group may have been

due to the “Hawthorne effect”

Main Article

Omega-3 PUFAs improved endothelial function and arterial stiffness with a parallel anti-inflammatory effect in adults with metabolic syndrome

Tousoulis, D., Plastiras, A., Siasos, G., Oikokomou, E., Verveniotis, A., Kokkou, E., & Maniatis, K. (2014). Omega-3 PUFAs improved endothelial function and arterial stiffness with a parallel antiinflammatory effect inadults with metabolic syndrome. Atherosclerosis, 232, 10-16.

MAIN ARTICLE: TOUSOULIS ET AL • Purpose: Evaluate the effects of n-3 PUFAs on

vascular function and inflammatory processes in subjects with MetS

• Methods: Double-blind, placebo-controlled, crossover design

Subjects randomly assigned to either a control group (N=14) or experimental group (N=15) for 12 weeks

o Experimental: Regular diet + daily N-3 PUFA capsule (2g/day, 46% EPA & 38% DHA)

o Control: Regular diet + daily placebo capsule

Statistical Analysis: ANOVA

- Subjects instructed to avoid changes in diet or exercise patterns

- Compliance monitored by daily physical activity and diet logs

- Those on cardiovascular or inflammatory medications were excluded

RESULTS

• Significant reductions in total cholesterol, triglycerides, and LDL-C at day 28

• Significant improvements in FMD, PWV, lipid profile, glucose, IL-6, and PAI-1 at day 84

• Endothelial function and arterial stiffness significantly improved

• Inflammation significantly reduced

• Normalization of fibrinolysis

STRENGTHS/WEAKNESSES

Strengths• Double-blind, placebo controlled• Crossover design• Strictly controlled for confounding variables

(medications, diet, exercise)• Length of study (3 months)• Multiple measurements to test endothelial function

Weaknesses• Didn’t test other inflammatory markers (CRP, TNF-a,

IL-8)• Small sample size (29)

SUMMARY OF FINDINGS Study Objective ConclusionLombardo et al

- Supporting Article 1

Investigate the effectiveness of fish oil to reverse dyslipidemia, insulin resistance, and adiposity induced by long term feeding of a sucrose-rich diet

Dietary fish oil reverses dyslipidemia and improves insulin action and adiposity in SRD fed rats.

Ebrahimi et al

- Supporting Article 2

To investigate the effect of n-3 PUFAs on established cardiovascular risk factors including anthropometric and biochemical parameters and heat shock protein (Hsp) 27 antibody titres in subjects with metabolic syndrome

Omega-3 supplementation improves the cardiovascular risk profile of subjects with MetS, having positive effects on weight, BMI, systolic blood pressure, lipid profile, and markers of inflammation and immunity.

Tousoulis et al

- Main Article

Evaluate the effects of n-3 PUFAs on vascular function and inflammatory processes in subjects with MetS

Treatment with omega-3 PUFAs may favorably affect endothelial function and the elastic properties of the arterial tree in MetS subjects, with a parallel anti-inflammatory effect.

FUTURE STUDIES

Defining the optimal N-6/N-3 ratio for metabolic syndrome

Further understanding of the underlying cellular mechanisms used by N-3 PUFAs

Studying N-3 effects on subjects with different genotypes

Differentiating the independent effects of EPA vs. DHA vs. ALA

Long term effects of omega-3 PUFA supplementation

TAKE HOME MESSAGE

Reducing the intake of omega-6, and increasing the intake of omega-3 PUFAs, will be beneficial for reversing the aberrations of metabolic syndrome including hypertriglyceridemia, high LDL-C, central obesity, endothelial dysfunction, and inflammation.

THANK YOU!

REFERENCES Carpentier, Y. A., Portois, L., & Malaisse W.J. (2006). n-3 Fatty acids and the metabolic syndrome The American

Journal of Clinical Nutrition, 83, 1499-1504. Clarke, S. D. (2001). Polyunsaturated Fatty Acid Regulation of Gene Transcription: A Molecular Mechanism to

Improve the Metabolic Syndrome. The Journal of Nutrition, 131, 1129-1132. Daviglus, M. L., Stamler, J., Orencia, A. J., Dyer, A. R., Liu, K., Greenland, P., ... & Shekelle, R. B. (1997). Fish

consumption and the 30-year risk of fatal myocardial infarction. New England Journal of Medicine, 336(15), 1046-1053.

Delarue, J., Guen, V.L., Corporeau, C., & Guillerm, S. . (2007). Can Marine Omega 3 Fatty Acids Prevent and/or Treat Metabolic Syndrome? . Current Nutrition & Food Science, 3, 151-156.

Dolecek, T. A., & Grandits, G. (1991). Dietary polyunsaturated fatty acids and mortality in the Multiple Risk Factor Intervention Trial (MRFIT). World review of nutrition and dietetics.

Dyerberg, J., Bang, H. O., Stoffersen, E., Moncada, S., & Vane, J. R. (1978). Eicosapentaenoic acid and prevention of thrombosis and atherosclerosis?. The Lancet, 312(8081), 117-119.

Dyerberg, J., & Bang, H. O. (1979). Haemostatic function and platelet polyunsaturated fatty acids in Eskimos. The Lancet, 314(8140), 433-435.

Ebrahimi, M., Ghayour-Mobarhan, M., Rezaiean, S., Hoseini, M., Parizade, S.M., Farhoudi, F., & Hosseininezhad, S.J. (2009). Omega-3 fatty acid supplements improve the cardiovascular risk profile of subjects with metabolic syndrome, including markers of inflammation and auto-immunity Acta Cardiologica, 64(3), 321-327.

Flachs, P., Rossmeisl, M., & Kopecky, J. . (2014). The Effect of n-3 Fatty Acids on Glucose Homeostasis and Insulin Sensitivity Physiological Research, 63, 93-118.

Friend, A., Craig, L., & Turner, S. (2013). The prevalence of metabolic syndrome in children: a systematic review of the literature. Metabolic syndrome and related disorders, 11(2), 71-80.

REFERENCES CONT. Hirai, A., Hamazaki, T., Terano, T., Nishikawa, T., Tamura, Y., Kumagai, A., & Sajiki, J. (1980). EICOSAPENTAENOIC ACID

AND PLATELET FUNCTION IN TAPANESE. The Lancet, 316(8204), 1132-1133. Hu, F. B., Bronner, L., Willett, W. C., Stampfer, M. J., Rexrode, K. M., Albert, C. M., ... & Manson, J. E. (2002). Fish and

omega-3 fatty acid intake and risk of coronary heart disease in women. Jama, 287(14), 1815-1821. Kremer, J. M., JUBIZ, W., MICHALEK, A., RYNES, R. I., BARTHOLOMEW, L. E., BIGAOUETTE, J., ... & LININGER, L. (1987).

Fish-oil fatty acid supplementation in active rheumatoid arthritis: a double-blinded, controlled, crossover study. Annals of internal medicine, 106(4), 497-503.

Kris-Etherton, P. M., Harris, W.S., & Appel, L.J. (2002). Fish Consumption, Fish Oil, Omega-3 Fatty Acids, and Cardiovascular Disease. Circulation, 106, 2747-2757.

Kromann, N., & Green, A. (1980). Epidemiological studies in the Upernavik district, Greenland. Acta Medica Scandinavica, 208(1‐6), 401-406.

Kromhout, Daan, Edward B. Bosschieter, and Cor de Lezenne Coulander. "The inverse relation between fish consumption and 20-year mortality from coronary heart disease." New England journal of medicine 312.19 (1985): 1205-1209.

Lombardo, Y. B., Hein, G., & Chicco, A. (2007). Metabolic Syndrome: Effects of n-3 PUFAs on a Model of Dyslipidemia, Insulin Resistance, and Adiposity Lipids, 42, 427-437.

Lopez-Huertas, E. (2012). The effect of EPA and DHA on metabolic syndrome patients: a systematic review of randomised controlled trials British Journal of Nutrition, 107, 185-194.

Lorenta-Cebrian, S., Costa, A.G., Navas-Carretero, S., Zabala, M., Martinez, J.A., & Moreno-Aliaga, M.J. (2013). Role of omega-3 fatty acids in obesity, metabolic syndrome, and cardiovascular disease: a review of the evidence Journal of Physiology and Biochemistry, 69, 633-651.

Poudyal, H., Panchal, S.K., Diwan, V., & Brown, L. . (2011). Omega-3 fatty acids and metabolic syndrome: Effects and emerging mechanisms of action. Progress in Lipid Research, 50, 372-387.

REFERENCES CONT. Prickett, J. D., Robinson, D. R., & Steinberg, A. D. (1983). Effects of dietary enrichment with eicosapentaenoic

acid upon autoimmune nephritis in female NZBxNZW/F1 mice. Arthritis & Rheumatism, 26(2), 133-139. Robinson, L. E., Buchholz, A.C., & Mazurak, V.C. (2007). Inflammation, obesity, and fatty acid metabolism:

influence of n-3 polyunsaturated fatty acids on factors contributing to metabolic syndrome Applied Physiology, Nutrition, and Metabolism, 32, 1008-1024.

Robinson, L. E., & Mazurak, V.C. (2013). N-3 Polyunsaturated Fatty Acids: Relationship to Inflammation in Healthy Adults Exhibiting Features of Metabolic Syndrome Lipids, 48, 319-332.

Simopoulos, A. P. (1991). Omega-3 fatty acids in health and disease and in growth and development. The American journal of clinical nutrition, 54(3), 438-463.

Simopoulos, A. P. (2002). Omega-3 fatty acids in inflammation and autoimmune diseases. Journal of the American College of Nutrition, 21(6), 495-505.

Tousoulis, D., Plastiras, A., Siasos, G., Oikokomou, E., Verveniotis, A., Kokkou, E., & Maniatis, K. (2014). Omega-3 PUFAs improved endothelial function and arterial stiffness with a parallel antiinflammatory effect inadults with metabolic syndrome. Atherosclerosis, 232, 10-16.