World Cancer Research Fund, Cancer Research UK and Oxford Population Health today announce results from a new study in which low- and non-meat-eaters had a lower risk of being diagnosed with cancer in comparison with regular meat-eaters.* The study is published today in the open access journal BMC Medicine.
The researchers from Oxford Population Health analysed the diets of more than 450,000 people and categorised them into diet groups depending on their meat intake. Regular meat-eaters were classified as those who consumed processed meat, red meat or poultry more than five times a week; and low meat-eaters less or equal to five times a week. The study also analysed people who didn’t eat meat but did eat fish (pescatarians), and the final group included vegetarians who never consume any meat or fish.
- Overall, they found that compared with regular meat-eaters, the risk of developing any type of cancer was 2% lower in low meat-eaters, 10% lower in fish-eaters, and 14% lower in vegetarians.
- Low meat-eaters had a 9% lower risk of developing bowel cancer in comparison with regular meat-eaters.
- Vegetarian women had a lower risk of post-menopausal breast cancer (18%) in comparison with regular meat-eaters, which was found to be potentially due to the lower body mass index observed in vegetarian women.
- Pescatarians and vegetarians had a lower risk of prostate cancer (20% and 31%, respectively) in comparison with regular meat-eaters.
The lower risk of bowel cancer in low meat-eaters is consistent with World Cancer Research Fund’s Third Expert Report** and Oxford Population Health’s findings*** that there is strong evidence that consuming red or processed meat increases the risk of bowel cancer.
Cody Watling, from Oxford Population Health’s Cancer Epidemiology Unit and lead researcher, said:
Previous evidence has suggested that vegetarians and pescatarians may have a lower risk of developing cancer. However, the evidence for a lower risk of developing specific types of cancer has been inconclusive. Being overweight after menopause is known to increase the risk of breast cancer and so the reduced risk of post-menopausal breast cancer in vegetarian women, due to lower BMI, was unsurprising – but we were surprised by the substantially lower risk of prostate cancer in vegetarians. Our group in Oxford is doing further research, funded by World Cancer Research Fund, to assess the risk of cancer across diet groups with larger numbers of vegetarians and pescatarians, as well as looking at vegans separately, to further explore potential explanations for differences in risk of specific types of cancer.
Dr Giota Mitrou, Director of Research and Innovation at World Cancer Research Fund International, said:
One in two of us will get cancer in our lifetime. And while there are lots of things about cancer we cannot control, we know that currently 40% of cancer cases could be prevented through lifestyle changes including diet, weight and physical activity. The results of this large, British study – part-funded by a grant from World Cancer Research Fund and released during Cancer Prevention Action Week – suggest that specific dietary behaviours such as low meat, vegetarian or pescatarian diets can have an impact on reducing the risk of certain cancers: in this case bowel, breast and prostate. The findings support our Cancer Prevention Recommendations to limit red and processed meat and increase intake of wholegrains, vegetables, fruit and pulses.
References
* Watling, C., Schmidt, J., Dunneram, Y.et al. Risk of cancer in regular and low meat-eaters, fish-eaters, and vegetarians: a prospective analysis of UK Biobank participants. BMC Med 20, 73 (2022). https://doi.org/10.1186/s12916-022-02256-w.
** World Cancer Research Fund/ American Institute of Cancer Research. Diet, Nutrition, Physical activity and Cancer: a Global Perspective. Continuous Update Project Expert Report 2018. Available at: dietandcancerreport.org
*** Bradbury, K.E., Murphy, N. and Key, T.J., 2020. Diet and colorectal cancer in UK Biobank: a prospective study. International journal of epidemiology, 49(1), pp.246-258. Available at: https://academic.oup.com/ije/article/49/1/246/5470096?login=true
