A small study was done on women who drank beverages with caffeine. The results showed that it mattered if the woman was Caucasian, black-African, or Asian.

Regarding coffee, Asian women had a jump in estrogen levels.  Caucasian women had a huge drop in estrogen, and black-African women had very little change.

The study also suggested that women of child bearing age are not affected by coffee: “For women of reproductive age, drinking coffee will not alter their hormonal function in a clinically significant way.”-Enrique Schisterman, Eunice Kennedy Shriver National Institute of Child Health and Human Development

However, caffeinated soda pop, and black teas, caused an across the board increase in estrogen for all women in the study!  The researchers are concerned because some cancers are linked to high levels of estrogen.

The study did not look at how caffeine affects women older than 44 years.  It was released online in the American Journal of Clinical Nutrition.

2010: ALCOHOL IN ENERGY DRINKS? NOT MANY.