Drink coffee moderately

Caffeine consumption at any level seems to have no association with the overall risk of breast cancer, according to a new study by researchers at Tokyo Women’s Medical University. However, higher caffeine consumption may increase cancer risk among women with histories of benign breast tumors.

Caffeine can be found in many products — coffee, tea, cocoa and chocolate, soft drinks, and some medications — which may make it the most widely consumed drug in the world. A previous study observed that women diagnosed for non-malignant breast disease found some relief after caffeine in their diet was eliminated.

The current study therefore tried to test the hypothesis that caffeine raised breast cancer risks.

The researchers conducted the study on 38,432 women, all at least age 45, who provided information about their dietary habits. Over a follow-up period of 10 years, invasive breast cancer developed in 1,188 women (3 percent). All the women were health-care professionals, with 3 of 4 being registered nurses.

Nearly 25 percent of the group did not drink coffee at all, while another 25 percent drank only one cup or less per day. Moderate consumers, at 2-3 cups a day, comprised about 33 percent, and the rest consumed four cups or more a day.

It turned out the hypothesis did not hold true. Consumption of caffeine did not have any statistically significant relationship with the overall risk of developing breast cancer.

However, among women who had a history of benign breast disease, the women with high consumption levels of caffeine appeared to have a significant but borderline increase in cancer risk. High consumers also had 79 percent higher risk of getting tumors at least two centimeters in size.

High caffeine consumption also seemed to increase by 68 percent the risk of estrogen-related types of breast cancer.

The researchers stress that the observations on the sub-groups and the role of caffeine need to be confirmed through further studies. They note that estrogen-related breast diseases and tumors larger than two centimeters usually lead to poor outcomes. The findings only suggest that caffeine could influence the rate of progression of existing tumors in the breast or aggressive types of cancer.

The more significant take-home message from the study, according to the authors, is that women do not need to worry about breast cancer risk even if they habitually consume coffee in moderate amounts.

A similar study published last May, which involved 86,000 female nurses tracked over a 22-year follow-up period, found that the overall risk of breast cancer did not increase in relation to coffee or caffeine consumption.

Safety Tip:

* Drink coffee moderately.