Cancer rates are generally lower among vegetarians compared
to meat eaters, but a new study suggests that this may not apply to all types
of cancers.
The study included 32,403 meat eaters, 8,562 non-meat eaters
who ate fish and 20,601 vegetarians. After an average of 12.2 years, 2,204 meat
eaters (6.8 percent), 317 fish eaters (3.7 percent) and 829 vegetarians (4
percent) developed various types of cancer.
The findings, published in the British Journal of Cancer, suggest that the risk of developing
stomach cancer, bladder cancer, non-Hodgkin's lymphoma and multiple myeloma may
be cut by more than half in vegetarians.
The association was particularly strong for multiple
myeloma, a type of bone marrow cancer. Vegetarians were 75 percent less likely
to develop the disease than meat eaters. In addition, vegetarians and fish
eaters were about one-third less likely to develop stomach cancer than meat
eaters. Although the number of stomach cancer cases was small, earlier research
suggests that processed meat may contribute to the disease.
In contrast, vegetarianism was not linked to a reduced risk
of colon or rectal cancer. In fact, the incidence of these cancers was slightly
higher among vegetarians than meat eaters. However, this risk was not
statistically significant, meaning that the higher rate may be due to chance.
Additionally, the risk of cervical cancer was significantly
higher among vegetarians than meat eaters. This increased risk was similar,
although not statistically significant, among fish eaters compared to meat
eaters. It has been suggested, but not scientifically proven, that dietary
factors may contribute to the risk of infection with the human papillomavirus,
which causes many cases of cervical cancer. The authors caution that these
findings are based on only 50 cervical cancer cases and may be influenced by
other factors, such as cervical cancer screening.
The authors conclude that more research is needed to fully
understand the relationship between vegetarianism and cancer risk.
For more information about vegetarianism, please visit
Natural Standard’s Health & Wellness database.