Nutrition, lifestyle and colorectal cancer incidence: a prospective investigation of 10 998 vegetarians and non-vegetarians in the United Kingdom

Abstract

In a cohort of 10 998 men and women, 95 incident cases of colorectal cancer were recorded after 17 years. Risk increased in association with smoking, alcohol, and white bread consumption, and decreased with frequent consumption of fruit. The relative risk in vegetarians compared with nonvegetarians was 0.85 (95% CI: 0.55 -1.32).

Cancer incidence in British vegetarians

“…vegetarians (Sanjoaquin et al, 2004;Key et al, 2009). We also noted previously in EPIC-Oxford, that the incidence of colorectal cancer among vegetarians was identical to that in the general population of England and Wales (standardised incidence ratio 102% (95% CI: 80 -129); Key et al, 2009).…”

“…In the Adventist Health Study in California, vegetarians had a significantly lower risk for cancers of the colon and prostate than non-vegetarians, but the risk for breast cancer did not differ significantly between these dietary groups (Fraser, 1999). In Britain, the Oxford Vegetarian Study suggested no large difference in the incidence of colorectal cancer between vegetarians and non-vegetarians (Sanjoaquin et al, 2004), whereas the UK Women's Cohort Study suggested that women who did not eat any meat had a lower risk for breast cancer than did meat eaters (Taylor et al, 2007). The first results from EPIC-Oxford suggested that the incidence of breast cancer did not differ significantly between vegetarians and non-vegetarians (Travis et al, 2008), that the incidence of colorectal cancer was higher in vegetarians than in meat eaters, that the incidence of lung cancer was lower in fish eaters than in meat eaters, and that the risk for all malignant cancers was lower in fish eaters and possibly lower in vegetarians than in meat eaters (Key et al, 2009).…”

“…In this paper, we have pooled the individual participant data from the Oxford Vegetarian Study and EPIC-Oxford; hence, this includes data previously reported from these individual studies (Sanjoaquin et al, 2004;Travis et al, 2008;Key et al, 2009). The follow-up time has been extended and, whereas our previous reports included results for only five cancer sites, in this study we have reported the results for 20 cancer sites or groups of sites.…”

Intake of dairy products and risk of colorectal neoplasia

“…Data on fermented milk products such as yoghurt suggest no relationship with CRC risk (22,23,30,38) . For cheese intake, RR range from 0·68 to 1·35 and in most studies the RR was greater than 1·0, although none of these relationships were statistically significant (17,22,23,27,30,34,38) . Some studies (27,38) have attempted to separate hard cheese from soft cheeses such as ricotta and cottage cheese, with the latter appearing to have a protective effect; however, the relationships were not significant and it is difficult to draw any reasonable conclusions from such few studies.…”

“…Milk is the dairy product that shows the most consistent relationship with CRC risk. Of the cohort studies to date that have investigated this relationship, most showed nonsignificant decreased risks of CRC with increasing milk intake (12,17,19,22,23,27,29,30,33,34,38) . Most studies have considered all types of milk together, but where these have been separated there are differences between low-fat v. whole milk.…”