In October 2018 researchers from the USA and Canada published the results of their study to assess the effect of coffee, tea and caffeine on the risk of breast, endometrial and ovarian cancers. A total of 3,185 women were involved in the study. Information on lifestyle and diet was collected via self-administered lifestyle and dietary questionnaires. During an average follow-up of approximately 12 years, 922 breast cancer, 180 endometrial cancer and 104 ovarian cancer diagnoses were made. Results showed that coffee, tea, and caffeine intake was not associated with the overall risk of ovarian cancer. However, a higher intake of coffee, caffeinated coffee and/or caffeine in pre-menopausal and normal weight women did appear to be associated with an increased risk of breast cancer. The findings also suggested that coffee and/or caffeine may be associated with a reduced risk of endometrial cancer.
Arthur R et al. Associations of coffee, tea and caffeine intake with risk of breast, endometrial and ovarian cancer among Canadian women. Cancer Epidemiol. 2018 Oct;56:75-82