A large study offers a reassuring message for coffee drinkers: caffeine, even in large amounts, doesn't increase breast cancer risk. These results add to other research that also has found no link between caffeine and breast cancer risk.
The researchers looked at the health information of more than 39,000 women who participated in the Women's Health Study. None of the women had been diagnosed with breast cancer when the study started. Questionnaires asked the women about their diets, including how much caffeine they consumed each day. Most of the caffeine came from coffee, but tea, diet and regular cola, and chocolate also added to daily caffeine consumption:
- 24% of the women never drank coffee
- 33% of the women drank two to three cups of coffee per day
- 15% of the women drank at least four cups of coffee per day
The researchers compared the caffeine intake of women who developed breast cancer to the caffeine intake of women who didn't develop breast cancer. The analysis found no link between overall breast cancer risk and caffeine intake. The way the caffeine was consumed (in coffee, tea, cola, or chocolate) also didn't have any effect on risk.
The results did show a slight increase in the risk of hormone-receptor-negative breast cancer among women who consumed the largest daily amounts of caffeine, but the researchers said this increase was likely due to chance and not due to caffeine consumption.
The researchers also found slight increases in risk among women with a history of non-cancerous breast disease who consumed large amounts of caffeine daily. Still, this increase also was likely due to chance and not due to caffeine consumption.
While there seems to be no link between caffeine and breast cancer risk, other diet and lifestyle choices can affect your risk of breast cancer. Visit the Breastcancer.org Lower Your Risk section to learn about diet and lifestyle options to keep your risk as low as it can be.