Four or more coffees reduce risk of womb cancer

By Dr. Ananya Mandal, MDJan 1 2012

According to a new study drinking four or more cups of coffee a day may reduce risk of developing endometrial cancer or womb cancer by almost 25 per cent.

Originating in the lining of the uterus, endometrial cancer is one of the most widespread invasive gynecological cancers. High levels of estrogen and insulin are associated with an increased risk of the disease but researchers involved in the Nurses' Health Study from the Department of Nutrition at the Harvard School of Public Health have discovered that high-coffee-consuming women have lower levels of these hormones, compared with those who drink little or no coffee.

“This is an observational study - coffee intake is self-selected, not randomized - so our study cannot prove causal relationship between coffee and endometrial cancer risk, but we found an inverse association between coffee and endometrial cancer risk,” said study author Youjin Je, doctoral student at the Harvard School of Public Health. “Four or more cups of coffee may contribute to lower risk of endometrial cancer by lowering levels of estrogen and insulin which are related to endometrial carcinogenesis due to increased cell proliferation and reduced cell death,” Je noted.

For the study the researchers looked at 67,470 women aged 34 to 59 from 1980 to 2006 and asked that them to report every four years how frequently, on an average, did they consume coffee over the previous year.

They then calculated cumulative average coffee intake to show long-term consumption patterns for the individual subjects and found that those who had four cups per day on an average were 25 per cent less likely to develop the cancer. And it is not just caffeine that helps decrease the risk as participants who drank two or more cups of decaffeinated coffee per day experienced a 22 per cent decrease.

But Je also cautioned that a high intake of sugars and fats in coffee might counteract the proposed benefits of consumption. “Based on scientific evidence, substantial amounts of sugar or cream can contribute to weight gain and insulin resistance, which is related to increased risk of endometrial cancer,” said Je. “Thus, women who typically added lots of sugar and cream to coffee may not have any benefits from coffee drinking against endometrial cancer.”

Though consuming four cups of coffee each day is not advised for pregnant women, those controlling their blood pressure or with sensitivity to caffeinated beverages, scientists say that it is perfectly safe for the rest of the population. In addition to the reduced risk of endometrial cancer laboratory testing has found that coffee has strong antioxidant properties that protect cells, protein and DNA against oxidative damage by directly neutralizing reactive oxidants or by modulating gene expression contributing to oxidative stress. Thus coffee has the potential to prevent a number of chronic diseases. Research over the past few years suggests that coffee consumption may protect against type 2 diabetes, Parkinson's disease, cirrhosis of the liver, depression in women and other cancers including aggressive prostate cancer.

“It's not at the stage where we would recommend women who don't drink coffee to start drinking,” said Je. “More large prospective studies should be done to further clarify the role of coffee among different subgroups. But, yes, women consuming coffee should feel reassurance that coffee in general is not a harmful substance, and may even offer some health benefits.”