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An EPIC undertaking Lessons for vegetarians and vegans from the EPIC-Oxford study Paul Appleby September 2008. The European Prospective Investigation into Cancer and Nutrition (EPIC) Largest ever ‘cohort’ study of diet and health 520,000 participants in 10 European countries
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An EPIC undertaking Lessons for vegetarians and vegans from the EPIC-Oxford study Paul Appleby September 2008
The European Prospective Investigation into Cancer and Nutrition (EPIC) • Largest ever ‘cohort’ study of diet and health • 520,000 participants in 10 European countries • Coordinated at the International Agency for Cancer Research (IARC, part of WHO) • Investigating the relationships between diet, lifestyle and environmental factors and the incidence of cancer and other chronic diseases
TROMSØ UMEÅ AARHUS MALMÖ COPENHAGEN UTRECHT CAMBRIDGE POTSDAM BILTHOVEN OXFORD HEIDELBERG PARIS IARC MILAN LYON TURIN OVIEDO FLORENCE SAN SEBASTIAN PAMPLONA BARCELONA NAPLES ATHENS MURCIA RAGUSA GRANADA EPIC: 520,000 men and women in 10 countries Tromsø Umeå Malmö Aarhus Copenhagen Oxford Cambridge Potsdam Heidelberg Utrecht Bilthoven Paris (nationwide) Turin Milan Florence Naples Ragusa Oviedo San Sebastian Pamplona Murcia Granada Athens (nationwide)
EPIC-Oxford • Recruitment 1993-1999 throughout the UK • Aim to recruit as many vegetarians as possible: through GPs for the ‘general public’, by post for vegetarians • Participants: • 65,500 diet group, basic characteristics • 57,500 lifestyle and food frequency questionnaire (FFQ) • 31,000 first 7-day food diary (1993-99) • 19,200 blood sample (1993-98) • 38,000 first follow-up questionnaire (2000-03) • 31,600 second follow-up questionnaire (2007-08) • 14,000 second 7-day food diary (2007-08)
Diet groups For many analyses EPIC-Oxford participants have been divided into one of 4 diet groups. Group Men Women Total Meat eaters 7,800 26,100 33,900 (52%) Fish eaters 1,700 8,400 10,100 (15%) Vegetarians 4,200 14,700 18,900 (29%) Vegans 900 1,700 2,600 ( 4%) Total 14,600 50,900 65,500 (Numbers rounded to the nearest 100)
Main findings from EPIC-Oxford to date • lifestyle characteristics and nutrient intakes • diet and body mass index / weight gain • hypertension and blood pressure • hormones and diet • diet and fracture risk • diet and cancer incidence • diet and mortality • miscellaneous
Selected lifestyle characteristics Women Characteristic Meat Fish Veg Vegan Median age 48 39 35 32 Current smoker (%) 11 8 8 10 University degree (%) 35 47 44 45 Married (%) 71 63 61 51 Men Characteristic Meat Fish Veg Vegan Median age 51 42 39 35 Current smoker (%) 10 10 9 8 University degree (%) 50 61 55 49 Married (%) 77 69 66 50
Mean daily nutrient intakes for women Nutrient Meat Fish Veg Vgn DRV Energy (MJ) 8.02 7.75 7.60 6.97 8.10 Carbohydrate (% E) 48.3 51.2 52.9 56.1 47 Protein (% E) 17.3 14.9 13.8 13.5 14.7 Total fat (% E) 31.5 30.7 30.4 27.8 33 Saturated fat (% E) 10.4 9.3 9.3 5.1 10 PUFA (% E) 5.2 5.4 5.3 7.2 6 Dietary fibre (g NSP) 18.9 21.6 21.8 26.4 18 Folate (µg) 321 346 350 412 200 Vitamin B12 (µg) 7.0 4.9 2.5 0.5 1.5 Calcium (mg) 989 1021 1012 582 700 Iron (mg) 12.6 12.8 12.6 14.1 14.8
Mean daily nutrient intakes for men Nutrient Meat Fish Veg Vgn DRV Energy (MJ) 9.18 8.90 8.78 8.01 10.6 Carbohydrate (% E) 46.9 49.8 51.2 54.9 47 Protein (% E) 16.0 13.9 13.1 12.9 14.7 Total fat (% E) 31.9 31.1 31.1 28.2 33 Saturated fat (% E) 10.7 9.4 9.4 5.0 10 PUFA (% E) 5.2 5.6 5.7 7.5 6 Dietary fibre (g NSP) 18.7 22.1 22.7 27.7 18 Folate (µg) 329 358 367 431 200 Vitamin B12 (µg) 7.3 5.0 2.6 0.4 1.5 Calcium (mg) 1057 1081 1087 610 700 Iron (mg) 13.4 14.0 13.9 15.3 8.7
Men Women Davey et al, Public Health Nutrition 2003; 6: 259-268
Mean annual weight gain (grams) during 5 years of follow-up by diet group Diet group Men Women Meat eater 406 423 Fish eater 377 338*** Vegetarian 386 392 Vegan 284* 303* ‘Reverted’1 468 433 ‘Converted’2 242*** 301*** Means are adjusted for age at recruitment, smoking, physical activity, marital status, current paid job, age left school, and age at menarche in women. * / *** denotes significantly lower mean weight gain compared with meat eaters at the P<0.05 / P<0.001 significance level. 1 denotes subjects who changed their diet to include more animal foods during follow-up. 2 denotes subjects who changed their diet to include fewer animal foods during follow-up.
Prevalence of self-reported hypertension by diet group Women (% with self-reported hypertension) Adjusted for Meat Fish Veg Vegan P Age alone 12.1 9.6 8.9 7.7 <0.001 Age & BMI 10.6 9.7 8.7 8.3 0.07 Men (% with self-reported hypertension) Adjusted for Meat Fish Veg Vegan P Age alone 15.0 9.8 9.8 5.8 <0.001 Age & BMI 12.9 9.3 9.5 6.1 0.01
Mean systolic blood pressure by diet group Women Adjusted for Meat Fish Veg Vegan P Age alone 120.1 119.0 120.0 117.6 <0.005 Age & BMI 119.7 119.4 120.2 118.4 0.08 ‘everything’* 119.4 119.4 120.3 119.5 0.21 Men Adjusted for Meat Fish Veg Vegan P Age alone 126.6 125.3 125.5 122.4 <0.005 Age & BMI 126.0 125.4 125.8 123.5 0.18 ‘everything’* 125.0 125.7 126.2 125.2 0.66 * - age, BMI, non-dietary factors, nutrient intakes
Self-reported fracture risk by diet group in EPIC-Oxford Diet group IRR (95% CI)1 IRR (95% CI)2 Meat eaters 1.00 (reference) 1.00 (reference) Fish eaters 1.01 (0.88-1.17) 1.05 (0.90-1.21) Vegetarians 1.00 (0.89-1.13) 1.02 (0.90-1.15) Vegans 1.30 (1.02-1.66) 1.00 (0.69-1.44) 1 Fracture incidence rate ratio compared with meat eaters among all participants, adjusted for age, sex and various non-dietary factors 2 As above, but restricted to participants consuming at least 525 mg/day calcium
Cancer in vegetarians: incidence rate ratios for vegetarians compared to non-vegetarians All results adjusted for age, sex, smoking and study, as applicable: Key at al Am J Clin Nutr 1999, and unpublished 2008.
EPIC-Oxford: standardized mortality ratios as percentages, compared to UK national rates, among all participants aged below 90 with known diet group
Mortality in EPIC-Oxford: deaths before age 90 among participants with no prior IHD, stroke or cancer *Adjusted for age, sex and smoking
Miscellaneous findings • higher frequency of bowel movements among vegetarians and vegans • compared with people who become vegetarian when adult, life-long vegetarians do not differ in adult height, weight, BMI or age at menarche in women
Selected Publications • Allen NE, Appleby PN, Davey GK, Key TJ. Hormones and diet: low insulin-like growth factor-I but normal bioavailable androgens in vegan men. British Journal of Cancer 2000; 83: 95-97. • Appleby PN, Davey GK, Key TJ. Hypertension and blood pressure among meat eaters, fish eaters, vegetarians and vegans in EPIC-Oxford. Public Health Nutrition 2002; 5: 645-654. • Davey GK, Spencer EA, Appleby PN, Allen NE, Knox KH, Key TJ. EPIC-Oxford: lifestyle characteristics and nutrient intakes in a cohort of 33883 meat-eaters and 31546 non meat-eaters in the UK. Public Health Nutrition 2003; 6: 259-268. • Spencer EA, Appleby PN, Davey GK, Key TJ. Diet and body mass index in 38000 EPIC-Oxford meat-eaters, fish-eaters, vegetarians and vegans. International Journal of Obesity 2003; 27: 728-734. • Key TJ, Appleby PN, Davey GK, Allen NE, Spencer EA, Travis RC. Mortality in British vegetarians: review and preliminary results from EPIC-Oxford. American Journal of Clinical Nutrition 2003; 78: 533S-538S. • Appleby P, Roddam A, Allen E, Key T. Comparative fracture risk in vegetarians and non-vegetarians in EPIC-Oxford. European Journal of Clinical Nutrition 2007; 61:1400-1406.
Further information and acknowledgements EPIC-Oxford website: www.epic-oxford.org Thanks are owing to all participants in EPIC-Oxford, and to Professor Tim Key and colleagues past and present at the Cancer Epidemiology Unit, Oxford University. EPIC-Oxford is supported by Cancer Research UK, the Medical Research Council, and the European Community.