Which foods may affect your colon cancer risk?
By Nicholas Bakalar
Can the foods we eat affect our risk of developing colon cancer? Studies have suggested that diet may alter the chances, but there has been little analysis of the strength of the evidence.
Now a review of 45 meta-analyses devoted to the subject has found that of 109 dietary factors identified as influencing the risk for colorectal cancer, there is solid evidence for only five.
The review, which is in JAMA Network Open, found convincing evidence that higher intakes of fiber, calcium supplements and yogurt are associated with a lower risk of colon cancer.
Eating red meat and heavy consumption of alcohol, on the other hand, may increase your risk. For 30 other dietary factors, there was suggestive or weak evidence for some effect, but insufficient evidence for the other 74.
Some studies suggest that certain vitamins may lower risk, but this study found almost no evidence that vitamin A, vitamin B6, folic acid, vitamin D or vitamin E had any effect in cancer reduction. The study found good evidence that four or more alcoholic drinks a day increased the risk compared with no alcohol at all.
The researchers found that a Mediterranean-style diet or a vegetarian diet had some moderate or suggestive effect in risk reduction, as did consumption of milk and cheese.
The review is limited to observational studies, so the findings are only an association and cannot prove cause and effect. In addition, there was no specific data on how sex, age groups or specific amounts of foods might affect risk.