Coffee and other caffeinated drinks can change a woman’s estrogen levels – raising them for some, lowering them for others -- but they don’t affect ovulation or pose a health risk, new research finds.
Researchers from the U.S. National Institutes of Health tracked more than 250 women of child-bearing age -- 18 to 44 years old – for up to two menstrual cycles between 2005 and 2007. They measured their coffee intake and changes in the levels of the female reproductive hormone.
What they found:
• Asian women who consumed the equivalent of two cups of coffee daily had elevated estrogen levels, compared to women who consumed less;
• White women who drank about two cups of coffee a day had slightly lower estrogen levels than women who consumed less; and
• Black women who consumed two cups of coffee a day also had elevated estrogen levels, but this finding was not statistically significant.
The women drank a variety of caffeinated drinks: coffee, black tea, green tea and soda, according to the study published in the American Journal of Clinical Nutrition.
“The effects of caffeine on estrogen are so minimal that in healthy women, it has no impact on ovulation or overall health, at least in the short term," the researchers wrote.
Nearly 90 percent of U.S. women drink the equivalent of about cups of coffee a day, the researchers said.