A meta-analysis of nine studies involving 1.8 million adults found that vegetarians have a lower risk for cancers of the pancreas, breast, prostate, and kidney as well as lower risk for multiple myeloma. Surprisingly, it also found that vegans had a 40% higher risk for colon cancer.

For a couple of reasons, I’m not especially alarmed by these findings. The authors noted that the statistical power was low since there were so few vegans with cancer in this study. They wrote:

“The higher risk of colorectal cancer observed in vegans is based on only 93 incident cases among vegans in seven studies in the UK and US, with <10 cases in vegans in five of these studies and therefore should be interpreted with caution.”

Also, the findings were no longer significant when the researchers excluded the first 4 years of follow-up. That’s important because cancer develops over a long time and can’t necessarily be linked to subjects’ more recent diet choices.

But while I don’t want to overstate the significance of these findings, I do want ... Read More >