Results from a decades-long study may enable women to drink coffee or tea without worry that doing so will increase their risk for breast cancer, study findings suggest, Reuters reported.
"In this large cohort of women, with 22 years of follow-up, we observed no association between coffee (caffeinated or decaffeinated) and tea consumption and the risk of breast cancer," Dr. Davaasambuu Ganmaa told Reuters Health.
"Coffee and tea are remarkably safe beverages when used in moderation,"
said Ganmaa, of the Harvard School of Public Health in Boston, Massachusetts.
Ganmaa and colleagues assessed coffee, tea, and caffeine consumption among 85,987 women who participated in the Nurses' Health Study. The women were between 30 and 55 years old at the start of the study.
Over 22 years of follow up, 5,272 women developed breast cancer.
After accounting for other factors potentially associated with breast cancer risk, such as age, smoking status, body mass, physical activity, alcohol intake, family history, menopausal status, history of hormone therapy, and number of children, the researchers found no elevated risk of breast cancer among women who reported drinking 4 or more cups of caffeinated or decaffeinated coffee or tea per day, compared with those who drank less than 1 cup daily.
They also found no apparent association between the occurrence of breast cancer and intakes of other caffeinated soft drinks and chocolate, which contribute to overall caffeine intake.
When the researchers further assessed breast cancer risk specifically among postmenopausal women, they found a modestly reduced risk associated with the highest versus the lowest caffeine intake. But, "this relation needs to be examined further," the investigators note.