July 7, 2009 – Vegetarianism may help reduce the incidence of several types of cancer, according to the results of a British study. Researchers at the University of Oxford conducted a large observational study1 with 61,566 subjects followed for 12 years.
Of the participants, 32,403 were omnivorous, that is, they ate meat, and 29,173 were vegetarians. Among vegetarians, 8,562 ate fish. The researchers identified all cases of cancer that occurred among participants during the study.
The results indicate that 5.5% of the subjects suffered from cancer (all types combined) during the 12 years of follow-up. This proportion was 6.8% among omnivores, 4% among strict vegetarians, and 3.7% among vegetarians who ate fish. The authors report that, compared to omnivores, strict vegetarians experienced a 12% reduction in the relative risk of developing cancer. This proportion was 18% among vegetarians who ate fish.
According to the results, the type of cancer for which vegetarianism would have the strongest protective effect is stomach cancer: researchers report a 64% decrease in the relative risk for vegetarians and 71% for those who eat Fish. These data would tend to confirm the hypothesis according to which the consumption of meat increases the risk of suffering from this type of cancer, while the consumption of vegetable fibers lowers this risk.
The protective effect was also significant, although to a lesser degree, for cancers of the ovaries, prostate, bladder as well as for non-Hodgkin lymphoma (lymphatic cancer) and multiple myeloma, a rare form of bone marrow cancer.
The results also revealed an opposite phenomenon that the researchers cannot explain: the vegetarians who participated in the study were twice as likely as the women who ate meat to suffer from cervical cancer.
The researchers say it is premature to draw conclusions about the overall effects of vegetarianism on cancer rates in the general population. These results could not justify, for the moment, to advise everyone to adopt a vegetarian diet, they add.
Pierre Lefrançois – PasseportSanté.net
According to The Guardian and BBC.
1. Key TJ, Appleby PN, et al. Cancer incidence in British vegetarians. Br J Cancer. 2009 Jul 7; 101 (1): 192-7.
