(D) Decreases the risk for major coronary heart disease # HRT may actually prevent the development of heart disease and reduce the incidence of heart attack in women between 50 and 59.> Unopposed estrogen (the supplementation of endogenous estrogens without a progestagen) can also result in endometrial hyperplasia, a precursor to endometrial cancer.> The extensive use of high-dose estrogens for birth control in the 1970s is thought to have resulted in a significant increase in the incidence of this type of cancer.> Hormone therapy taken soon after menopause may help protect against dementia, even though it raises the risk of mental decline in women who do not take the drugs until they are older.> Dementia risk was 1 % in women who started HRT early, and 1.7% in women who didn't, (e.g. women who didn't take it seem to have had--on average--a 70% higher relative risk of dementia).> This is consistent with research that hormone therapy improves executive and attention processes in postmenopausal women.