Nutrition in a nutshell

www.stgeorges.nhs.uk

WelcomeNutrition in a nutshell - how to eat

healthy and live longer Catherine Collins RD FBDA

Principal dietitian, St George’s Hospital


Dietary change is a common New Year resolution

“We have a population in constant state of high alert for foods that will kill them or cure them

– Good foods will not only make us healthy, but also righteous

– Bad foods make us sinful – and will kill us” Tim Byers

Short-term extreme dietary habits often started – and quickly suspended – at this time of year


What is a dietitian?

‘Dietitians translate the science of nutrition into practical information about food. They work with people to promote nutritional well-being, prevent food-related problems and treat disease.’

NHS Careers web page


Dietitians: a profession “uniting food, culture and science to improve human health and quality of life”

Dr Johanna Dwyer; US NIH

What is a dietitian?

Dietitian is a ‘legally protected’ term.It is illegal to use the title unless you are a dietitian.


Anyone can be a nutritionist…

or ‘Leading Clinical Nutritionists’…

or ‘Nutritional Therapists’…

… the term is not ‘protected’ by law

How many of you are nutritionists?


Life expectancy

80% of life is disease free

78 yearsmen

82 yearswomen


Longer old age or longer ill health? Life expectancy has increased for both men and women

Age at which we develop a ‘serious illness’ that will affect our life is static

We have one additional year of ill health before we die, based on current UK statistics

So far, healthy diet and lifestyle appears to optimise health and longevity. The evidence for vitamin supplements is not only in its infancy, but at the moment appears not proven.


Nutrition and healthWhere’s the evidence?Population studies Organ healthIndividuals Cell function

Environment DietLifestyle and activity


The ‘Mediterranean diet’

Where did the idea of the ‘Mediterranean Diet’ originate?

Great Britain – or Greece?


James Lind (1716-1794) Surgeon on HMS Salisbury First nutrition experiment at sea in 1747 identified oranges and lemons to have "most sudden and

good effects" in treating scurvy, a condition responsible for the death of two thirds of sailors on traditional ocean sailing routes

Trading links with British Caribbean lead to limes becoming a standard fruit carried on board. British sailors became known as ‘Limeys’

Lime juice cordial was developed to provide an alternative to the storage of limes in alcohol

The Merchant Shipping Amendment Act of 1867 made it law to carry lemons or limes on seafaring vessels

British nutrition research…The first randomised controlled trial


Sir Jack Drummond (1891-1952) Pioneer of vitamin research in the 1930-40’s Advised the Ministry of Food on suitable food

rations, and the use of vitamin supplements in WWII

Frederick, Lord Woolton (1883-1964) Appointed Minister of Food in 1940 Became infamous for his PR campaigns - particularly the ‘Woolton steak and kidney pie’

(a vegetable pie containing no steak, and no kidney, because these meats were rationed)

British nutrition research…


Public health nutrition (1940-1955)typical weekly ration,1942

540 g of meat (fish, sausages and offal were off ration)

4 oz (113g) of bacon/ham 3 pints of milk 1 oz (28 g) cheese 2 oz (57 g) butter 2 oz (57 g) fat or lard 2 oz (57 g) loose tea 1-4 eggs 2oz jam + 3oz sweets + 3oz

sugar + "points" for tinned/ dried food

Note: less saturated fat and sugar than pre-war diet


‘Dig for Victory’ increased intake of vegetables and fruit

Fortification of food offset rationing:– Calcium added to the ‘National’

bread (continues today)– Vitamins A and D added to

margarine (continues today)

Promotion of vitamin supplements:– ‘welfare vitamins’ – Cod liver oil– Orange juice

Rationing


The ‘Mediterranean Diet’

Dr Ancel Keys (1904-2004)

US Nutritional physiologist, seconded to the UK Ministry of Food during WWII

Noted a higher mortality in US peers compared to UK when he returned to the US

Hypothesis that rationing improved health of society – particularly with respect to saturated fat and cardiovascular disease

Developed the Seven Countries Collaborative Study launched 1958

Monitored 13,000 men aged 40–59 years on diet, health and lifestyle with repeated health assessments after 5 and 10 years


The ‘Mediterranean’ diet blueprint:Cretan diet of the 1950’s

simple food components; regular meals based on wholegrain carbohydrates at least 5 portions of fruit and vegetables daily predominant fat - mono-unsaturated fat in olive oil regular omega-3 fat intake from oily fish modest amounts of lean meat less full fat dairy foods

Confirmed similar finding to that of British Diet during rationing!


Saturated fat raises ‘bad’ cholesterol and increases risk of heart disease and stroke

Saturated fat - when made into cell membranes - boosts inflammation and promotes short term and long term cell damage

It is the proportion of saturates, rather than the amount, that is of concern

Cut fat from meat before cooking, and use vegetable oil if necessary

Choose potato-topped rather than pastry pies

Choose scones and bread rather than pastries and cakes

Swap butter for unsaturated spreads, preferable mono-unsaturated ‘olive’ type spreads. If you must have butter, go for lower fat spreadable versions

Dietary fat: the messages

LESS THAN a third of total fat to come from saturates


Cell communicationhelps organise the body response

Cells ‘talk’ to each other by using lots of different methods, including sending signals from their outer layer, the cell membrane

When a cell becomes inflamed the membrane fat releases chemicals to ‘warn’ other cells

These cells ‘tell’ other cells and the inflammation message continues The type of fat in the diet, and so in our cell membranes, influence this response-

and is noticeable in conditions like arthritis


Membrane response

Saturated fats make cell membranes more reactive, sending out ‘loud’ messages to other cells, making pain and inflammation worse.

Polyunsaturates from corn and sunflower oil (omega-6 polyunsaturates) do exactly the same

Omega-3 polyunsaturates (e.g. rapeseed oil, fish oils) send out weaker signals, lessening inflammation response

Mono-unsaturates (e.g. rapeseed oil and olive oil) send out very weak signals

Having more mono-unsaturates and omega-3, and less omega-6 and saturated fats in the diet, is the optimal choice


Vegetable oils

Rapeseed oil

Sunflower oil

Olive oil

kcals per 100ml 825 825 882

Total fat content 92 92 98

Saturates 6 11 14

Monounsaturates 55 19 74

Polyunsaturates 27 58 11

Olive oil is rich in anti-oxidant polyphenols

Rapeseed oil is a good source of omega-3 fat

Although all are low in saturates, sunflower oil has a high polyunsaturate content so is not the healthiest choice


Eat more fruit and veg 5-a-day is the minimum to provide:

– Vitamins and minerals– Soluble ‘gel’ type fibres for healthy bowel bacteria, and a lower

cholesterol– Plant chemicals - ‘phytochemicals’ – often more powerful than

vitamins: lycopene, lutein, quercetin, polyphenols, anthocyanins– Different colours provide different phytochemicals

A ‘portion’ is a ‘handful’:– 1 tablespoon cooked vegetables– 1 orange/ 2 satsumas– 150ml fruit juice/ fruit smoothie (equal to 1 small carton)

Choose fresh, frozen, canned, dried


How to do it…

1. Have a glass of fruit juice with breakfast

2. Make one of your between-meal snacks a piece of fruit

3. Have a tomato or side salad with lunchtime meal

4. Have two veggies (potatoes DON’T count) with your evening meal

5. Canned or frozen fruits and vegetables are just as good


lycopenecarotenoids

polyphenols

Vitamin C

folic acid

PhytoenePhytoflueneLutein + zeaxanthin

Quercetin KaempferolNaringenin

Dietary anti-oxidants help limit cell damage

Food is more important than focussing on nutrients…

9-oxo-octadecadienoic acid

A tomato has much more functionality than the sum of its vitamin content


Should I choose organic?

More ‘biologically active’ phytochemicals per 100g:– Plant protection from pests e.g. glucosinolates, allicin– Protection from UV light damage e.g. lutein, lycopene– Greater measured anti-oxidant potential in test tube

analysis

BUT - People eat portions, not weight units– We eat a ‘unit’ such as an apple or one tomato – not

‘100g of apple’– Non-organic foods tend to be bigger, so unit-for-unit

both contain similar phytochemical levels per serving


Best cooked - or raw? Cooking destroys some heat-sensitive

vitamins e.g. vitamins B and C Cooking increases your choice of

vegetables (e.g. potato, aubergine, turnip)

Cooking softens the plant cell walls, releasing cell contents more readily such as beta-carotene

Anti-oxidant lycopene in tomatoes is made more soluble by cooking, so is absorbed by the body in greater amounts – especially when in the presence of oil or fat in the diet

Eat both raw and cooked vegetables – both are good in different ways


Superfoods…are just foods with good PR

All fruits and vegetables provide both nutrients and non-nutritive beneficial agents (‘phytochemicals’)

Superfoods are those with research to prove their phytochemical usefulness

A higher level of anti-oxidant potential from phytochemicals in a food does not necessarily mean greater health benefit

If the anti-oxidants are cleared quickly from the blood their usefulness is limited

Using the example of pomegranate juice vs. tea…


Pomegranate juice:Ellagitannins, anthocyanins

Tea: theaflavones, catechins,

phenolic acids

Blood levels of dietary antioxidantsover a 6 hour period

Regular tea consumption sustains anti-oxidant activity over the day


Pomegranate juice boosts blood levels of antioxidants ellagitannins and anthocyanins

BUT how many glasses of pomegranate juice did you drink today? The answer is often ‘none’

Tea also contains antioxidants – particularly EGCG, other catechins, thearubigins and theaflavins

The British drink more tea than pomegranate juice

… so the overall anti-oxidant benefit is similar from both.

Superfoods? It’s just clever marketing


Fruits, vegetables:vitamins, minerals, phytochemicals, fibre, very low in calories

Nutritional blueprint for a healthy diet: the food matrix

‘Lean’ protein foods:Iron, B12, mono- and omega-3 fats

Wholegrain carbs:main energy source for brain; blood sugar control; B group vitamins, fibre

Low fat dairy foods:calcium-rich, variable fat content, probiotic

Fats and oils:Mono-unsaturates and fish oils reduce inflammation; fat-soluble vitamins; better blood sugar control; helps absorb important nutrients


Mediterranean diet helps weight control:kcal per 100g food

African diet: 107 kcal

Healthy diet: 125 kcal

British diet: 160 kcal

Fast food outlet: 262 kcal

The more fruit and veg you eat, the lower your overall calorie intake per day


How reliable is the evidence?

Is it a large study? Small studies often end up with errors that affect the

results. Tossing a coin three times doesn’t give you the correct answer

as to whether 100 coins would land head down if you dropped them –

getting this result is chance

Is it reported in a major health journal? Or is it a small survey or

personal anecdote to promote a product such as a vitamin supplement?

Does it generally conform with what we already know, perhaps

adding a different angle? If it doesn’t, then its likely to be a faulty study


The EPIC study:European Prospective Investigation of Cancera ‘big’ study with little left to ‘chance’

Initial data collected from 1992 – 2000

512,000 healthy people in 10 European countries

Includes 90,000 British men + women

Repeated surveys every 3 years

Followed for 10 years so far….


More dairy foods and calcium reduce bowel cancer High fibre or a high fish intake reduces the risk from

meat intake

Cancer risk factors High intakes of processed meats and red meat High fat diets High alcohol intake Being overweight or obese

EPIC findings so far….


Fruits and vegetables

High fibre intake reduces bowel cancer risk

High intakes of fruit and vegetables lowers all cancer risk

The study does not discriminate organic from non-organic produce

(Lowers risk of heart attack and stroke)


It’s never too late to change!

Cardiac events 35% reduction

All cause mortality 40% reduction

15,792 men and women aged 45 to 64, taking part in an American heart disease risk (ARIC) study

970 (8.4%) newly adopted a healthy lifestyle:– at least 5 portions of fruits and veg daily– at least 2½ hours per week of exercise– maintain BMI between 18.5 – 30– stopped smoking


We should all join Club-Med!

12 research studies addressing ‘Mediterranean Diet’ 1,574,299 subjects followed for 3-18 years

9% reduction in overall death rates 9% less in death from cardiovascular disease 6% less in risk of cancer, or dying from cancer 13% reduction in risk of Parkinson’s disease and Alzheimer’s

disease

Sofi et al: British Medical Journal11th September 2008


Are supplements of use?

Folic acid 400g daily before and for the first three months of pregnancy help prevent spina bifida and similar defects

Vitamin D for everyone – especially if you avoid the sun, and for ALL children under 2 and ALL pregnant women. Adult dose is 10-25g of Vitamin D daily. Take with food.

One-a-day broad spectrum multivitamins and minerals providing 50-100% RDA provides useful ‘health insurance’ if concerned about dietary quality


No effective UVB sunlight of the right wavelength in the UK from November to March

60% of potent UVB sunlight to make Vitamin D occurs between the hours of 11am – 3pm

The amount of Vitamin D made in 25 peak time minutes in the South would take 1-2 hours in the North!

Cloud cover reduces the suns effectiveness by half

New guidelines suggest 10-15 minutes of peak sunlight exposure a couple of times a week is safe.

Darker skinned people need 5-10 minutes longer due to natural skin protection

Vitamin D from sunlight…


“One hundred years after the first vitamin was named, what is known about them has not translated into beneficial, standardised recommendations for public health”

Prof Irwin RosenbergUSDA Human Nutrition

Research on Aging

Are vitamins really a natural extension of a healthy diet?


The expert view…

“Food, not specific nutrients, is the fundamental unit to health in human nutrition”Professor Linda TapsellSmart Foods Centre, University of Woolongong, Australia

“We are confusing ourselves and the public by talking so much about nutrients when we should be talking about foods…”“consumers get the idea that diet and health can be understood in terms of specific nutrients”“It’s not the best approach and may be wrong”Professor David Jacobs, University of Minnesota


To summarise… Eat more fruit and veg - why not try a new one occasionally?

Have at least 1 meat free meal each week Eat regularly, and aim for three meals a

day Choose wholegrain or wholemeal more

often than white for bread, pasta and rice Enjoy a little of what you fancy – be it

alcohol or chocolate! Reduce your saturated fats, choosing

monounsaturated fat in preference Exercise and lifestyle also influences

health

Does this mean me?


“Food is part of a balanced diet”

Enjoy!

Nutrition in a nutshell

Health & Medicine

Transcript of Nutrition in a nutshell