New research has shown that women suffer from heart attacks and heart disease about a decade later than men, who lack estrogen in their system. Previous studies show that once estrogen levels drop after a woman goes through menopause, heart disease rates rapidly increased.

However, in the latest research published in the Journal of the American Heart Association, researchers show that these previous studies are indeed false. Researchers believe that heart disease in women peaks in the years directly before menopause, and that the risk is especially great amongst African-American women.

Dr. Mark DeBoer, associate professor of Pediatrics at the University of Virginia, explains to Time that his study of 1,470 women over 12 years shows the opposite results. He says, “As much as conventional wisdom has been that it’s menopause itself, and being post menopausal, that increases heart disease risk, it appears that the time leading up to menopause is associated with more rapid change in heart risk factors. Once menopause is in place, there is a slower chance in these factors.”

For African-American women, these risk factors — including a large waist, high triglyceride levels, high blood pressure and high blood sugar when fasting — steadily increased tenfold than they did in their white counterparts.

DeBoer even tried to explain if this phenomenon was the result of women taking hormone replacement supplements. Doctors previously believed that in giving women higher supplements of estrogen, their heart disease risk would decrease. Ultimately, research proved that this was not the case.

So now, DeBoer is trying to determine if estrogen actually has any effect on heart disease. What he does know is that menopause is an incredibly important time for women to focus on their health to lower their risk of metabolic disease.

Across the nation, heart disease is a serious epidemic in post-menopausal women. In fact, 84% of people aged 65 years and older die from heart disease every year.