Drinking coffee may cut colon cancer risk in women

21 August, 2007:

Drinking three or more cups of coffee a day is likely to reduce the risk of colon cancer in women by half, according to a study by Japanese scientists.

However, no association was found between coffee drinking and the risk of rectum cancer in women.

The findings also pointed to a growing, yet weak, evidence that drinking coffee may protect against a range of cancers such as skin and liver cancer.

Researchers at Tokyo’s National Cancer Centre studied data from 46,000 men and 50,000 women aged between 40-69 over a period of up to 12 years from 1990. They found no significant benefit in men.

Even after adjusting for other factors, including diet and exercise, the researchers found that women who drank three or more cups of coffee a day had half the risk of developing colon cancer, compared with those who drank no coffee at all.

The researchers, whose findings have been published in the International Journal of Cancer, did not find any link between consumption of green tea and colon cancer.

Manami Inoue of the research team said that, in Japan, almost all the males drink alcohol and there are a large number of smokers. “There may be some benefit from coffee for men, but it may be that we were unable to adjust for these factors,” Inoue added.

The mechanism by which coffee may prevent cancer is unknown, Inoue said. The caffeine it contains could stimulate the working of the colon, or the effect could be due to coffee’s antioxidant properties.

The researchers concluded: Some people cannot tolerate caffeine, so they should not force themselves to drink coffee. But, for people who like it, there is no reason to give it up.

The results did not reveal any causal relationship between drinking coffee and the risk of colorectal cancer, meaning that drinking coffee does not guarantee a decrease in the risk of colorectal cancer, said a scientist affiliated with the website foodconsumer.org

An earlier study conducted in Japan involving 23,000 men and 25,000 women aged 40 to 64 years had negated any association between coffee consumption and incidence of either proximal or distal colon cancer.