Speak with one of our advisors: 0800 074 5888 or

Fish may provide clue to reducing risk of bowel cancer

24th March: New research into dietary patterns and the risk of colorectal cancers suggests that pesco-vegetarians (vegetarians who eat fish and seafood) may have a distinct advantage over vegans and vegetarians, as well as non-vegetarians.

The research – published in JAMA Internal Medicine, a specialist journal of the American Medical Association – set out to evaluate the association between vegetarian dietary patterns. The study’s abstract stated: “Colorectal cancers are a leading cause of cancer mortality, and their primary prevention by diet is highly desirable. The relationship of vegetarian dietary patterns to colorectal cancer risk is not well established.”

The Adventist Health Study 2 (AHS-2) from which the results were drawn is a large, prospective, North American cohort trial including 96,354 Seventh-Day Adventist men and women, recruited between 1 January 2002, and 31 December 2007. Of these participants, an analytic sample of 77,659 remained after exclusions, with cancers of the colon and rectum being identified primarily by state cancer registry linkages. Analysis was conducted between 1 June and 20 October, 2014 using Cox proportional hazards regression, taking into account important demographic and lifestyle confounders.

Diet was assessed at baseline by a validated quantitative food frequency questionnaire and categorised into four distinct vegetarian dietary patterns (vegan, lacto-ovo vegetarian, pesco-vegetarian, and semi-vegetarian) and a non-vegetarian dietary pattern.

During a mean follow-up of 7.3 years, 380 cases of colon cancer and 110 cases of rectal cancer were documented by the research team. The adjusted hazard ratios (HRs) in all vegetarians combined versus non-vegetarians were 0.78 (95% CI, 0.64-0.95) for all colorectal cancers, 0.81 (95% CI, 0.65-1.00) for colon cancer, and 0.71 (95% CI, 0.47-1.06) for rectal cancer. The adjusted HR for colorectal cancer in vegans was 0.84 (95% CI, 0.59-1.19); in lacto-ovo vegetarians, 0.82 (95% CI, 0.65-1.02); in pescovegetarians, 0.57 (95% CI, 0.40-0.82); and in semivegetarians, 0.92 (95% CI, 0.62-1.37) compared with nonvegetarians. Effect estimates were found to be similar for men and women, and for black and non-black individuals.

While vegetarian diets are associated with an overall lower incidence of colorectal cancers, the study indicated that pesco-vegetarians in particular have a much lower risk.

Justin Davies, Consultant Colorectal Surgeon at Addenbrooke’s Hospital, Cambridge and Clinical Adviser at Check4Cancer, commented: “This study shows a clear statistical correlation between specific diets and cancer risk; the next, more challenging, step is to establish causal links between those diets and colorectal cancers. The data on pesco-vegetarians certainly suggest some key areas of enquiry, and if such associations are causal, they could prove highly significant for primary prevention of colorectal cancers – especially if it is possible to determine what it is about the consumption of fish and seafood that reduces risk. At the very least this may provide new criteria from which to establish who may be at higher risk, and who should perhaps be offered early screening for these cancers.”

Affordable bowel cancer screening
For men and women aged 45+

Order online for quick delivery
Order online for quick delivery
Home Test Kit
Convenient at-home test
Rapid results, within 5 days
BHUK Promo image
If you want fast, accurate screening for bowel cancer
If you have a family history of bowel cancer
Request a call back
Submit your contact details and
we'll call you back
© 2020 BowelHealth UK, Lower Court 3-4, Copley Hill Business Park, Cambridge Road, Cambridge, CB22 3GN - Registered in England and Wales. Company registration number 08866941
All data send on this website is encrypted (SSL).