Coffee and Endometrial Cancer Risk

Drinking about four cups of coffee a day appears to reduce the risk of developing endometrial cancer, a British study reports.

Women who drank about four cups of coffee per day appeared to have decreased endometrial cancer risk compared with those who drank less than a cup each day, according to a study published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.

“We used a ‘nutrient-wide association study’ – a new approach – to systematically evaluate the association of dietary factors with endometrial cancer risk,” said Melissa A. Merritt, PhD, a research fellow in cancer epidemiology at Imperial College London in the United Kingdom and the study’s lead author.

Dr. Merritt and colleagues evaluated the association of 84 foods and nutrients based on dietary questionnaires from a prospective cohort study, the European Prospective Investigation Into Cancer and Nutrition (EPIC) Study.

They then validated nine foods and nutrients identified from the EPIC study as having associations with endometrial cancer risk in two large longitudinal prospective cohort studies of women, the Nurses’ Health Study (NHS) and NHSII, based at Brigham and Women’s Hospital, Boston, and Harvard School of Public Health, Boston, respectively.

Among the EPIC study participants, those who drank about three cups of coffee a day (750 g/day) had a 19 percent lower risk for endometrial cancer compared with those who drank less than one cup of coffee a day. Among the NHS/NHSII participants, those who drank about four cups of coffee per day (1,000 g/day) had an 18 percent lower risk for endometrial cancer compared with those who never drank coffee.

The endometrium is the lining of the uterus and cancers starting in this tissue are called endometrial cancers. Cancers of the muscle of the uterus are called uterine sarcomas.

This nutrient study examined 1,303 endometrial cancer cases in the EPIC study, and 1,531 endometrial cancer cases from the NHS/NHSII studies. The nine foods/nutrients that were found to have associations with endometrial cancer in the EPIC cohort were total fat, monounsaturated fat, carbohydrates, phosphorus, butter, yogurt, cheese, potatoes, and coffee.

Dr. Merritt noted that the observational study found an association between coffee consumption and endometrial cancer risk, but emphasized that further studies were needed to determine causation. In other words, additional research is needed to determine whether drinking coffee was the cause of the lower risk for the disease that was observed in this study.

“Coffee intake is worth investigating further to see if coffee can be used for the prevention of endometrial cancer,” Dr. Merritt said. “However, before clinical recommendations can be made, further studies are needed to evaluate this question in other studies and to try to isolate the components of coffee that may be responsible for any influence on endometrial cancer.”

Total fat, monounsaturated fat, and phosphorus were associated with decreased risk for endometrial cancer, and carbohydrates and butter intake were associated with increased risk for this type of cancer in the EPIC cohort, but these findings could not be validated in the NHS/NHSII cohorts.