What Coffee May Do for Women's Cancer Risk

Endometrial cancer risk may decline in women with higher coffee intake

(RxWiki News) Coffee drinkers of the world — the female coffee drinkers, that is — your morning cup of joe might just have some unexpected health benefits.

A large study on women in the US and Europe found that coffee may decrease the risk of endometrial cancer.

While these findings appear positive, they don't necessarily mean that coffee causes endometrial cancer risk to decline. The authors of this study only found a link between coffee and endometrial cancer — a cancer that begins in the lining of the uterus.

Edward Giovannucci, MD, ScD, a professor of nutrition and epidemiology at the Harvard School of Public Health, told dailyRx News that a single food or drink isn't usually solely responsible for a decrease in cancer risk. He said other factors like hormones can play a bigger role, and major diet patterns are more likely to have an effect than a single food.

"For example, obesity is by far the largest risk factor for endometrial cancer, probably due mostly to [the hormones] estrogen and insulin to a lesser degree," Dr. Giovannucci said. "In post-menopausal women, most of estrogen comes from production in fat tissue, so the larger the fat mass, the higher the estrogen. Thus, the overall diet that contributes to weight gain is important, but it is unclear what the role of a single food or nutrient may be.”

Dr. Giovannucci didn't discount coffee's potential cancer-busting benefits, though.

“Having said this, it is intriguing that a protective association of coffee has been observed remarkably consistently for endometrial cancer — many studies besides these 2," he said. "Coffee has also been shown to possibly affect estrogen and insulin levels, and it is extremely high in some potent unique [anti-cancer compounds].”

The authors of this study, led by Melissa A. Merritt, PhD, of Imperial College London's School of Public Health, looked at two large studies to assess links between foods and endometrial cancer.

These researchers used data from the European Prospective Investigation into Cancer and Nutrition (EPIC;N) and the US-based Nurses’ Health studies (NHS I/II). Both studies included large numbers of people who had been followed over many years. The NHS I study, for instance, began in 1976.

The patients in these studies filled out periodic surveys about their health, including diet, medication and other health habit topics.

From the original large groups — more than 400,000 women — in the combined studies, Dr. Merritt and colleagues selected more than 1,300 women from EPIC;N and more than 1,500 women from NHS I/II. All of these women had been diagnosed with endometrial cancer.

One factor was a standout in both studies: coffee. Women who drank more coffee had a lower risk of endometrial cancer than women who drank little or no coffee.

Dr. Merritt and team felt this result was tied to compounds in the coffee other than caffeine. Tea, which also contains caffeine, did not appear to lower endometrial cancer risk.

This study was published Feb. 9 in Cancer, Epidemiology, Biomarkers and Prevention.

EPIC is funded by government agencies in various European countries. Among these funding sources are the European Commission (DG-SANCO) and the International Agency for Research on Cancer Grant Support. The NHS studies are funded by the US National Institutes of Health.

Dr. Merritt and team disclosed no conflicts of interest.


Review Date: 
February 9, 2015