The long-term use of estrogen or estrogen plus progestin hormone therapy does not reduce the risk of dementia, according to findings published in the American Journal of Epidemiology. The study was by led Dr. Valerie Crooks, of Kaiser Permanente Southern California, Pasadena. The study included 2,900 dementia free women at baseline with 1500 on hormone therapy. The subjects were at least 75 years of age. Tests were conducted annually to measure cognitive ability.
Of the 1500 of the women in the study were hormone users, the average age at the start of hormone therapy was 48.3 years for those who used estrogen alone and 54.9 years for those who used estrogen/progestin. The average duration of hormone use was 30.5 years and 23.2 years for estrogen and estrogen/progestin users, respectively.
283 women developed dementia during over the course of the study. The study controlled for age, education, and medical history. The conclusion is that hormone use did not affect the risk of dementia when the intervention begins near or around post-menopause.
Hormone therapy cannot be fully dismissed as the types of hormones, levels of hormones, and the time of first administration has not been fully examined. Further, the identification of subsets of patients that might benefit from a hormone intervention has not been identified. More work is needed.