An EPIC undertaking Lessons for vegetarians and vegans from the EPIC-Oxford study Paul Appleby

An EPIC undertaking

Lessons for vegetarians and vegansfrom 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

EPIC: 520,000 men and women in 10 countries

IARC LYON

PARIS

FLORENCE

MILAN

RAGUSA

TURIN

NAPLESBARCELONA

OVIEDO

GRANADA

MURCIA

PAMPLONA

SAN SEBASTIAN

CAMBRIDGE

OXFORD BILTHOVEN

UTRECHT

ATHENS

HEIDELBERG

POTSDAM

MALMÖ

UMEÅ

AARHUS

COPENHAGEN

TROMSØTromsø

UmeåMalmö

AarhusCopenhagen

OxfordCambridge

PotsdamHeidelberg

UtrechtBilthoven

Paris (nationwide)

TurinMilanFlorenceNaplesRagusa

OviedoSan SebastianPamplonaMurciaGranada

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 characteristics57,500 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 TotalMeat 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

WomenCharacteristic Meat Fish Veg VeganMedian age 48 39 35 32Current smoker (%) 11 8 8 10University degree (%) 35 47 44 45Married (%) 71 63 61 51

MenCharacteristic Meat Fish Veg VeganMedian age 51 42 39 35Current smoker (%) 10 10 9 8University degree (%) 50 61 55 49Married (%) 77 69 66 50

Fruit, daily consumption by sex and diet group

0100200300400500600

men women

g/da

y

meat

fish

veget

vegan

Vegetables (excl legumes & potatoes), daily consumption by sex and diet group

0

100

200

300

400

men women

g/da

y

meat

fish

veget

vegan

Mean daily nutrient intakes for women

Nutrient Meat Fish Veg Vgn DRVEnergy (MJ) 8.02 7.75 7.60 6.97 8.10Carbohydrate (% E) 48.3 51.2 52.9 56.1 47Protein (% E) 17.3 14.9 13.8 13.5 14.7Total fat (% E) 31.5 30.7 30.4 27.8 33Saturated fat (% E) 10.4 9.3 9.3 5.1 10PUFA (% E) 5.2 5.4 5.3 7.2 6Dietary fibre (g NSP) 18.9 21.6 21.8 26.4 18Folate (µg) 321 346 350 412 200Vitamin B12 (µg) 7.0 4.9 2.5 0.5 1.5Calcium (mg) 989 1021 1012 582 700Iron (mg) 12.6 12.8 12.6 14.1 14.8

Mean daily nutrient intakes for men

Nutrient Meat Fish Veg Vgn DRVEnergy (MJ) 9.18 8.90 8.78 8.01 10.6Carbohydrate (% E) 46.9 49.8 51.2 54.9 47Protein (% E) 16.0 13.9 13.1 12.9 14.7Total fat (% E) 31.9 31.1 31.1 28.2 33Saturated fat (% E) 10.7 9.4 9.4 5.0 10PUFA (% E) 5.2 5.6 5.7 7.5 6Dietary fibre (g NSP) 18.7 22.1 22.7 27.7 18Folate (µg) 329 358 367 431 200Vitamin B12 (µg) 7.3 5.0 2.6 0.4 1.5Calcium (mg) 1057 1081 1087 610 700Iron (mg) 13.4 14.0 13.9 15.3 8.7

Body Mass Index by diet-group and 10 year age-group among 65,000 men and women in EPIC-Oxford

19

20

21

22

23

24

25

26

27

20- 30- 40- 50- 60- 70- 80- 20- 30- 40- 50- 60- 70- 80-

Age (years)

BM

I kg/

m2 meat

fish

veget

vegan

Davey et al, Public Health Nutrition 2003; 6: 259-268

Men Women

Mean annual weight gain (grams) during 5 years of follow-up by diet group

Diet group Men WomenMeat eater 406 423Fish eater 377 338***Vegetarian 386 392Vegan 284* 303*‘Reverted’1 468 433‘Converted’2242*** 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 PAge alone 12.1 9.6 8.9 7.7 <0.001Age & BMI 10.6 9.7 8.7 8.3 0.07

Men (% with self-reported hypertension)Adjusted for Meat Fish Veg Vegan PAge alone 15.0 9.8 9.8 5.8 <0.001Age & BMI 12.9 9.3 9.5 6.1 0.01

Mean systolic blood pressure by diet group

WomenAdjusted for Meat Fish Veg Vegan PAge 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

MenAdjusted for Meat Fish Veg Vegan PAge 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

Sex hormones and IGF in men

750 subjects in EPIC-Oxford: Allen et al 2000

Testosterone SHBG Free testo. (x 10) IGF-I0

10

20

30

40

50

60Serum concentration, nmol/l

Meat

Vegetarian

Vegan

P=0.003

P=0.001

P=0.14

P=0.002

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 factors2 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

Cancer Collaborative analysis of mortality, 1999

Latest results for cancer incidence, EPIC-Oxford

Deaths DRR Cancers IRR

Colorectal 278 0.99 (0.77-1.27) 228 1.46 (1.07-2.00)

Lung 203 0.84 (0.59-1.18) 88 1.24 (0.70-2.19)

Breast 210 0.95 (0.55-1.63) 728 0.94 (0.78-1.14)

Prostate 137 0.91 (0.60-1.39) 180 0.85 (0.57-1.27)

All cancers - - 2167 0.92 (0.82-1.02)

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

Cause of death

Deaths Non-vegetarians

Vegetarians All participants

All circulatory

931 39 (37-42) 41 (36-47) 40 (37-42)

IHD 464 36 (33-40) 34 (27-41) 36 (33-39)

Stroke 258 44 (38-51) 54 (41-68) 46 (41-52)

All causes 2889 47 (45-49) 48 (45-52) 48 (46-49)

Mortality in EPIC-Oxford: deaths before age 90 among participants with no prior IHD, stroke or cancer

Cause of death Deaths Death rate ratio for vegetarians versus non-vegetarians (95% CI)*

IHD 207 0.89 (0.63-1.34)

Stroke 155 1.17 (0.82-1.67)

Total circulatory 467 1.04 (0.84-1.30)

All causes of death 1458 1.08 (0.95-1.22)

*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.