Vegetarianismo e Prevenzione Oncologica

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1 X-Files in Nutrizione Clinica e Artificiale: Oncologia e Nutrizione, dalla Prevenzione alla Terapia Genova - 07 Giugno 2012 Vegetarianismo e Prevenzione Oncologica Filippo VALORIANI Anna Rita SABBATINI Emanuela ZAGALLO Dietetica e Nutrizione Clinica

Vegetarianism in perspective A person who does not eat meat (including fowl) or seafood, or products containing these foods 1 The eating patterns of vegetarians may vary

2 Vegetarianism in perspective A person who does not eat meat (including fowl) or seafood, or products containing these foods 1 The eating patterns of vegetarians may vary considerably 1 Considerable variation may exist in the extent to which animal products are excluded 1 1. Position of the American Dietetic Association: Vegetarian Diets. J Am Diet Assoc, 2009

3 Vegetarianism in perspective < 1/week 1. Fraser G. Am J Clin Nutr, 2009

Other kinds of Vegetarianism Macrobiotic Diet Based largely on grains, legumes, and vegetables. Fruits, nuts, and seeds are used to a lesser extent.

Raw Food Diet Consisting mainly or exclusively of uncooked and unprocessed fruits, vegetables, nuts, seeds, sprouted grains and beans.

4 Other kinds of Vegetarianism Macrobiotic Diet Based largely on grains, legumes, and vegetables. Fruits, nuts, and seeds are used to a lesser extent. Some people eat limited amounts of fish. Raw Food Diet Consisting mainly or exclusively of uncooked and unprocessed fruits, vegetables, nuts, seeds, sprouted grains and beans. In rare instances unpasteurized dairy products and even raw meat and fish. Fruitarian Diet Based on fruits, nuts, and seeds. Avocado and tomatoes are commonly included. Other vegetables, grains, beans, and animal products are excluded. 1. Position of the American Dietetic Association: Vegetarian Diets. J Am Diet Assoc, 2009

Vegetarianism and Cancer Risk Obesity is a significant risk factor for cancer at a number of sites 1 Vegetarians tend to have an overall lower cancer rate than does the general population 2 The lower

5 Vegetarianism and Cancer Risk Obesity is a significant risk factor for cancer at a number of sites 1 Vegetarians tend to have an overall lower cancer rate than does the general population 2 The lower BMI of vegetarians may explain some of the lower cancer risk in vegetarians compared with nonvegetarians 2 1. World Cancer Research Fund. DC: American Institute for Cancer Research; Winston JC. Nutr Clin Pract, 2010.

6 Vegetarianism and Cancer Risk

7 Vegetarianism and Cancer Risk

8 Vegetarianism and Cancer Risk

9 Vegetarianism and Cancer Risk

10 Vegetarianism and Cancer Risk

11 Vegetarianism and Cancer Risk

12 Vegetarianism and Cancer Risk

13 Vegetarianism and Cancer Risk

14 4 diet groups were established: - 1 MEAT EATERS (those that eat meat) - 2 FISH EATERS (those that do not eat meat but do eat fish) - 3 VEGETARIANS (those that do not eat meat or fish but do eat dairy products or eggs or both) - 4 VEGANS (those that eat no animal products)

15 Vegetarianism and Cancer Risk

16 Vegetarianism and Cancer Risk The incidence of all malignant neoplasms combined was lower among vegetarians and fish eaters than among meat eaters. The incidence of colorectal cancer was significantly higher among vegetarians than among nonvegetarians.

17 Vegetarianism and Cancer Risk In this relatively health-conscious cohort the pattern of the diet (excepting meats, fruit, and vegetables) was relatively similar to the UK population in most other respects, with high consumption of tea, sauces, cakes, soft drinks (women), butter and margarine 1 Differences in nutrient intake between British vegetarians (the few vegans excepted) are modest compared with nonvegetarians in the EPIC-Oxford study 2 Consider the possibility that some other factor confounds the meat colon cancer association in the United Kingdom and is not present in other parts of Europe or the United States 3 (composition of beef) 1. Slimani N et al. Public Health Nutr, Davey GK et al. Public Health Nutr, Fraser GE, Am J Clin Nutr, 2009

Vegetarianism and Cancer Risk Epidemiological studies have consistently shown that regular consumption of plant foods, such as fruit and vegetables, is strongly associated with a reduced risk of

18 Vegetarianism and Cancer Risk Epidemiological studies have consistently shown that regular consumption of plant foods, such as fruit and vegetables, is strongly associated with a reduced risk of cancer 1-3 Fruit and vegetables (fiber, Vit C) exhibit protective activity against cancer of the lung, mouth, esophagus, colon, and stomach and to a lesser degree some other site 3 The regular use of legumes provides a measure of protection against stomach, prostate cancer 3, and colon cancer 4, whereas a high intake of whole grains has provided some protection against colorectal and possibly other cancers Liu RH. Am J Clin Nutr, Jacobs DR. Nutr Cancer, World Cancer Research Fund. American Institute for Cancer Research; Fraser GE. Am J Clin Nutr, Jacobs DR et al. Nutr Cancer, Okarter N, Crit Rev Food Sci Nutr., Pelucchi C et al. Nutr Cancer, 2009

19 Reported a 25% reduction in risk of colorectal cancer in the highest quartile of dietary fiber intake compared to the lowest.

20 In populations with low average intake of dietary fibre, an approximate doubling of total fibre intake from foods could reduce the risk of colorectal cancer by 40%

Vegetarianism and Cancer Risk More detailed food consumption and food preparation data are needed as well as data on the bioavailability of protective phytochemicals

21 Vegetarianism and Cancer Risk More detailed food consumption and food preparation data are needed as well as data on the bioavailability of protective phytochemicals (flavonoids, indoles, sulfides, carotenoids) 1 The phytochemicals can display additive and synergistic effects 2 1. Winston JC. Nutr Clin Pract, Liu RH. J. Nutr, 2004

22 Vegetarianism and Cancer Risk

23 Vegetarianism and Cancer Risk Jia-Yi Dong, Li-Qiang Qin. Breast Cancer Res Treat, 2011

The protective effect of soy was only observed among studies conducted in Asian

24 Vegetarianism and Cancer Risk Soy isoflavones consumption was inversely associated with risk of breast cancer incidence (RR = 0.89, 95% CI: ). The protective effect of soy was only observed among studies conducted in Asian populations (RR = 0.76, 95% CI: ) but not in Western populations (RR = 0.97, 95% CI: ).

25 Vegetarianism and Cancer Risk Key TJ. Am J Clin Nutr, 1999

26 Key TJ. Am J Clin Nutr, 1999

27 In conclusion, vegetarians had a 24% lower mortality from ischemic heart disease than nonvegetarians, but no associations of a vegetarian diet with other major causes of death were established. Key TJ. Am J Clin Nutr, 1999

28 Vegetarianism and Cancer Risk No clear differences have been shown for other major causes of death such as stroke and cancers of the colo-rectum, breast and prostate.

29 Vegetarianism and Cancer Risk

Vegetarianism and Cancer Risk Human population studies have not shown large differences in cancer incidence or mortality rates between vegetarians and nonvegetarians 1

30 Vegetarianism and Cancer Risk Human population studies have not shown large differences in cancer incidence or mortality rates between vegetarians and nonvegetarians 1 There is a need for additional studies of the association between the spectrum of types of vegetarian diets and risk of chronic disease 1 1. Winston JC. Nutr Clin Pract, 2010

increased risk of cancer due to the presence of polycyclic aromatic hydrocarbons and heterocyclic amines

31 Vegetarianism and Cancer Risk Consumption of red meat and processed meat is consistently associated with an increase in the risk of colorectal cancer 1 Grilled, cured, and smoked meats and fish are associated with an increased risk of cancer due to the presence of polycyclic aromatic hydrocarbons and heterocyclic amines produced during their preparation World Cancer Research Fund. American Institute for Cancer Research; 2007

Health Implications of Vegetarian Diets Varied, balanced vegetarian diets tend to be lower in saturated fat and cholesterol, and have higher levels of dietary fiber, magnesium and potassium, vitamins

32 Health Implications of Vegetarian Diets Varied, balanced vegetarian diets tend to be lower in saturated fat and cholesterol, and have higher levels of dietary fiber, magnesium and potassium, vitamins C and E, folate, carotenoids, flavonoids and other phytochemicals 1 However, vegans and some other vegetarians may have lower intakes of vitamin B12, calcium, zinc, and long-chain n-3 fatty acids 1 Position of the American Dietetic Association: Vegetarian Diets. J Am Diet Assoc. 2009

33 Nutrition considerations for vegetarians: PROTEIN An assortment of plant foods eaten over the course of a day can provide all essential amino acids and ensure adequate nitrogen retention and use in healthy adults; complementary proteins do not need to be consumed at the same meal 1 A meta-analysis of nitrogen balance studies found no significant difference in protein needs due to the source of dietary protein 2 Ensure an adeguate intake of lysine: dietary adjustments such as the use of more beans and soy products in place of other protein sources that are lower in lysine or an increase in dietary protein from all sources 3 1. Young VR. Am J Clin Nutr Rand WM et al. Am J Clin Nutr, Position of the American Dietetic Association: Vegetarian Diets. J Am Diet Assoc. 2009

Nutrition considerations for vegetarians: PROTEIN Food and nutrition

than the Recommended Dietary Allowance in those vegetarians whose dietary

34 Nutrition considerations for vegetarians: PROTEIN Food and nutrition professionals should be aware that protein needs might be somewhat higher than the Recommended Dietary Allowance in those vegetarians whose dietary protein sources are mainly those that are less well digested, such as some cereals and legumes 1 1. FAO/WHO/UNU Expert Consultation on Protein and Amino Acid Requirements in Human Nutrition. World Health Organization; 2002.

in EPA and DHA 1 Vegetarians, and particularly vegans, tend to have lower blood levels of EPA and DHA than nonvegetarian

35 Nutrition considerations for vegetarians: n-3 FATTY ACIDS Vegetarian diets are generally rich in n-6 fatty acids, they may be marginal in n-3 fatty acids 1 Diets that do not include fish, eggs, or generous amounts of algae generally are low in EPA and DHA 1 Vegetarians, and particularly vegans, tend to have lower blood levels of EPA and DHA than nonvegetarian 2 1. Position of the American Dietetic Association: Vegetarian Diets. J Am Diet Assoc Rosell MS. Am J Clin Nutr. 2005

36 Nutrition considerations for vegetarians: n-3 FATTY ACIDS The bioconversion of α-linolenic acid (ALA) to EPA is generally less than 10% in humans; conversion of ALA to DHA is substantially less 1 Conversion rates for ALA tend to improve when dietary n-6 levels are not high or excessive 1 Vegetarians should include good sources of ALA in their diet, such as flaxseed, walnuts, canola oil, and soy 2 1. Williams CM. Proc Nutr Soc, Geppert J Lipids, 2005

Nutrition considerations for vegetarians: IRON Incidence of iron-deficiency anemia among vegetarians is similar to that of nonvegetarians 1 Although vegetarian adults have lower iron stores than

37 Nutrition considerations for vegetarians: IRON Incidence of iron-deficiency anemia among vegetarians is similar to that of nonvegetarians 1 Although vegetarian adults have lower iron stores than nonvegetarians, their serum ferritin levels are usually within the normal 1-2 Because of lower bioavailability of iron from a vegetarian diet, the recommended iron intakes for vegetarians are 1.8 times those of nonvegetarians 3 1. Ball MJ Am J Clin Nutr Alexander D Eur J Clin Nutr, Institute of Medicine, Food and Nutrition Board.Washington, DC: National Academies, 2001

38 Nutrition considerations for vegetarians: IRON Inhibitors of iron absorption: phytates, calcium, and the polyphenolics in tea, coffee, herb teas, and cocoa. Fiber only slightly inhibits iron absorption 1 Some food preparation techniques (soaking and sprouting beans, grains, and seeds, the leavening of bread, fermentation in miso and tempeh) can diminish phytate levels 2 and thereby enhance iron absorption 3,4 Vitamin C and other organic acids found in fruits and vegetables can substantially enhance iron absorption and reduce the inhibitory effects of phytate and thereby improve iron status 5,6 1. Coudray C et al. Eur J Clin Nutr, Harland BF, Nutr Res, Sandberg AS. Am J Clin Nutr, Manary MJ. Ann Trop Paediatr, Hallberg L. Am J Clin Nutr, Fleming DJ, Am J Clin Nutr, 1998

Nutrition considerations for vegetarians: B-12 Lacto-ovo-vegetarians can obtain adequate vitamin B-12 from dairy foods, eggs, or other reliable vitamin B-12 sources, for vegans, vitamin B-12 must be

39 Nutrition considerations for vegetarians: B-12 Lacto-ovo-vegetarians can obtain adequate vitamin B-12 from dairy foods, eggs, or other reliable vitamin B-12 sources, for vegans, vitamin B-12 must be obtained from regular use of vitamin B-12-fortified foods 1 Vegetarian diets are typically rich in folacin, which may mask the hematological symptoms of vitamin B-12 deficiency, so that vitamin B-12 deficiency may go undetected until after neurological signs and symptoms may be manifest 2 1. Position of the Am Diet Ass: Vegetarian Diets. J Am Diet Assoc Herrmann W. Clin Chem, 2001

40 Nutrition considerations for vegetarians: CALCIUM Calcium intakes of lacto-ovo-vegetarians are similar to, or higher than, those of nonvegetarians, whereas intakes of vegans tend to be lower than both groups and may fall below recommended intakes 1 The risk of bone fracture was similar for lacto-ovo-vegetarians and meat eaters, whereas vegans had a 30% higher risk of fracture possibly due to their considerably lower mean calcium intake (EPIC-Oxford Study) 2 1. FAO/WHO/UNU: Report of a Joint FAO/WHO/UNU Expert Consultation; Appleby P. Eur J Clin Nutr, 2007

41 Nutrition considerations for vegetarians: CALCIUM The ratio of dietary calcium to protein is a better predictor of bone health than calcium intake alone. Typically, this ratio is high in lactoovo-vegetarian diets and favors bone health, whereas vegans have a ratio of calcium to protein that is similar to or lower than that of nonvegetarians 1 Many vegans may find it is easier to meet their calcium needs if calcium-fortified foods or dietary supplements are utilized 1 1. Weaver C. Am J Clin Nutr, 1999

Nutrition considerations for vegetarians: ZINC The bioavailability of zinc from vegetarian diets is lower than from nonvegetarian diets, mainly due to the higher phytic acid content of vegetarian

42 Nutrition considerations for vegetarians: ZINC The bioavailability of zinc from vegetarian diets is lower than from nonvegetarian diets, mainly due to the higher phytic acid content of vegetarian diets 1 Zinc intakes of vegetarians vary with some research showing zinc intakes near recommendations 2 and other research finding zinc intakes of vegetarians significantly below recommendations 3-4 Due to the difficulty in evaluating marginal zinc status, it is not possible to determine the possible effect of lower zinc absorption from vegetarian diets 2 1. Hunt JR. Am J Clin Nutr, Davey GK. Public Health Nutr, Ball MJ. Am J Clin Nutr, Janelle KC. J Am Diet Assoc, 1995

43 Take Home Messages The eating patterns of vegetarians may vary considerably Evidence: not large differences in cancer incidence or mortality rates between vegetarians and nonvegetarians Regular consumption of plant foods is strongly associated with a reduced risk of cancer Consumption of red meat, processed meat, grilled, cured, and smoked meats and fish are associated with an increased risk of cancer There is a need for additional studies of the association between the spectrum of types of vegetarian diets and risk of cancer

44 Take Home Messages Appropriately planned vegetarian diets are healthful and nutritionally adequate; vegans and some other vegetarians may have lower intakes of some nutrients Food and nutrition professionals can assist vegetarian patients by providing current, accurate information about vegetarian nutrition, foods, and resources

45 Thank You Giuseppe Arcimboldo, Estate (1572), Denver Art Museum

National Food Service Management Institute. The University of Mississippi. NUTRITION 101: A Taste of Food and Fitness.

National Food Service Management Institute. The University of Mississippi. NUTRITION 101: A Taste of Food and Fitness. The University of Mississippi LESSON 6 HANDOUTS NUTRITION 101: A Taste of Food and Fitness Lesson 6 Handouts Pre-Quiz Lesson 6: Vegetarian Diets 1. Vegetarian diets can not meet the needs of growing children.