Fruit & Vegetables and the prevention of diseases – the evidence

1. Fruit & Vegetables and the prevention of diseases – the evidence Stephen Atkin Professor of Endocrinology and Metabolism Stephen.atkin@hyms.ac.uk

2. A balanced diet is very important

3. “Five a a day” • Change 4 life

4. The facts • Vitamins, minerals • Trace elements • Obesity • Cancer

5. Vitamins – water soluble or fat soluble Example of water soluble vitamin; Vitamin C • Citrus and soft fruits, green leafy vegetables. • Essential for collagen formation, enzyme co-factor, anti-oxidant prevention of damaging effects of free radicals. Also role in iron absorption. • deficiency – scurvy, more mild gum disease, loosening of teeth, easy bruising and poor wound healing. • infants (6-12 months). • Elderly. • Low income families.

6. Example of fat soluble vitamin; Β-carotene • Yellow, orange and green fruit and vegetables • Provitamin of Vit A. Vit A essential to processes of vision, reproduction, growth and cellular differentiati • Deficiency - Longterm inadequate intakes associated with night blindness, susceptibility to infection • Not seen in developed world as multiple sources of vit A • Fortification of margarines

7. Minerals

8. Magnesium • green leafy vegetables • cofactor for many enzymes, required for protein synthesis and for both anaerobic and aerobic energy synthesis • Deficiency linked to cardiovascular, skeletal, GI and CNS disorders

9. Potassium • Almost all fruit and vegetables • essential for the maintenance of normal osmotic pressure within cells, enzyme cofactor, required for secretion of insulin • Deficiency can cause rapid/irregular heart rhythm, muscle weakness

10. Trace elements

11. Cobalt • green leafy vegetables • essential trace element, integral part of vit B12, which is essential for folate and fatty acid metabolism, • molybdenum • legumes, green leafy veg, cauliflower • metalloenzyme function

12. manganese • green veg and tea • essential component of number of enzymes boron • almost all fruit and veg • involved in metabolism of various elements (including calcium copper and magnesium) glucose, triglycerides, oestrogen

13. Who needs fruit and veg when you have got it all in a tablet?

14. The biggest threat to the developed world?

15. Economic impact of obesity in England • The estimated annual cost of obesity to the economy is: • £3.5 billion for the UK economy • 18 million sick days • 40,000 lost years of working life National Audit Office Report. Tackling Obesity in England. London, 2001.

16. Consequences of obesity in adults • Associated with increased morbidity and mortality • Risk factor for range of chronic diseases • Cardiovascular disease (2-3 fold↑ risk) • Type 2 diabetes, hypertension (>3 fold↑ risk) • Some cancers e.g. colorectal, oesophageal, breast and endometrial • Increased likelihood of gallstones, osteoarthritis and high blood pressure (in turn increasing risk of stroke) • Increased complications during childbirth

17. Childhood obesity: parents will live longer than their children

19. Eat well plate Bread, cereals and potatoes Fruits and vegetables Meat, fish and protein alternatives Milk and dairy products Foods rich in sugars and fat Reproduced with kind permission of the Food Standards Agency

20. Protein Fruit Milk/yoghurt Vegetable Vegetable Starch/cereal Plate model (the one you actually eat off)

21. Relative risk of health problems associated with obesity Disease Women Men Type 2 diabetes Hypertension Myocardial infarction Colon cancer Angina Gall bladder disease Ovarian Cancer Osteoarthritis Stroke 12.7 4.2 3.2 2.7 1.8 1.8 1.7 1.4 1.3 5.2 2.6 1.5 3.0 1.8 1.8 - 1.9 1.3 National Audit Office Report. Tackling Obesity in England. London, 2001.

22. Cancer • Antioxidant effects of vitamins • Antioxidants such as vitamins C, E and A (in the form of carotenes): protect cells from toxic by products formed in the body • Free radicals • oxidation

23. FSA review of antioxidants in foods • Disease prevention of antioxidants: lower heart disease and cancer deaths • Do not get these effects from supps; need the complex of substances in fruit/veg

24. Heart disease • Free radicals • oxidation of cholesterol • LDL • Atherosclerosis – heart disease

25. Stroke • Meta analysis of 8 studies including 257 551 individuals • Compared with individuals who had less than three servings of fruit and vegetables per day, showed that fruit and vegetables had a significant protective effect on both ischaemic and haemorrhagic stroke

26. The evidence • Large well designed studies investigating effects of supplements – no evidence of benefit in cancer or heart disease • 7 studies vitamin E supplementation • 8 studies Beta carotene

27. dietary sources linked to lower rate of heart disease, for example the tomato • vitamin C • vitamins A and B, • potassium, iron and phosphorus. • Lycopene

28. The humble apple Vitamin A 67.5 IU Vitamin C 5.7mg Vitamin E (Alpha Tocopherol) 0.2mg Vitamin K 2.8mcg Niacin 0.1mg Vitamin B6 0.1mg Folic acid 3.8mcg Pantothenic Acid 0.1mg Choline 4.2mg Minerals Amounts Per Serving Calcium 7.5mg Iron 0.1mg Magnesium 6.3mg Phosphorus 13.8mg Potassium 134mg Sodium 1.3mg Fluoride 4.1mcg

29. Fibre • Fibre – populations with high fibre intake tend to have low risk of colon cancer (UK’s third most common cancer, claiming 18,000 lives in the UK each year) • Eating plenty fresh fruit and veg thought to prevent against this. • Insoluble fibre – fruit and veg contain this, keeps bowels healthy and stop constipation

30. Fibre • Breast cancer • Foods rich in this are more bulky so help make us feel full, which means we are less likely to eat too much.

31. Fibre content of fruit/veg (standard portion or one piece) g RDA Carrot 4.0 14% Broccoli 2.0 9% Peas 4.0 14% Spinach 2.0 7% Apple 3.0 12% Orange 4.0 14% Banana 6.0 23% Peach 3.0 12% Strawberries 3.0 12% White bread 1.0 4% Wholemeal bread 2.0 8% Pasta 2.5 10% Rice 1.0 4% (bread per slice approx)

32. Conclusion • Robust evidence that fruit and vegetables have added benefits globally for health that you cannot get by replacing them with pills and tablets