Caffeinated Soda Jacks Up Estrogen

The strangest thing about research showing that caffeine can alter a woman’s estrogen level is that it influences women of different races in different ways. In white women, caffeine has been shown to lower estrogen. But in Asian women, it jacks it up. In black women, it also seemed to increase estrogen, although the data was not statistically significant. Anahad O’Connor reports in the New York Times that the study,  published in The American Journal of Clinical Nutrition, analyzed data on more than 250 women who drank about one cup of coffee a day, and provided blood samples and information about their exercise, eating and smoking. The source of the caffeine also seemed to influence the results. PsychCentral reports that 200 milligrams (0ne cup of coffee) or more of caffeine from coffee was consistent with the findings for overall caffeine consumption—with Asians having higher estrogen levels, whites having lower estrogen levels, and the results for blacks not statistically significant. But drinking more than one cup each day of caffeinated soda or green tea was linked to higher estrogen level in Asians, whites, and blacks.