A potent brew

There's a correlation between moderate coffee drinking and reduced risk of colorectal cancer - but evidence of a causal link is still percolating.

- JENNIFER BOWDEN

QUESTION:

I recently read that drinking coffee lowers the risk of bowel cancer coming back. Does that mean it reduces the risk of getting bowel cancer in the first place? How does coffee help the bowel?

ANSWER:

Researchers have found intriguing links between coffee consumption and colorectal cancer risk. Regular coffee consumption is linked to a reduced risk of colorectal cancer occurrence and recurrence in some studies, including a recent large observational study in the Netherlands. But is there enough evidence to say that coffee could prevent colorectal cancer? The Dutch study used data from a longitudinal study investigating nutritional and lifestyle factors linked to cancer recurrence among 1719 colorectal cancer patients. They found drinking four or more cups of coffee daily was associated with a 32% lower risk of colorectal cancer recurrence compared with drinking less than two cups daily. However, a U-shaped relationship existed between coffee consumption and all-cause mortality: optimal health was associated with drinking 3-5 cups a day. The lowest risk was at four cups. Mortality risk was higher as coffee consumption increased or decreased.