The largest and best-controlled trial testing whether hormone “replacement” therapy prevented heart disease was stopped three years early in July 2002. The Women’s Heath Initiative (WHI) study included over 16,600 healthy menopausal women without symptoms. These women were randomized to daily conjugated equine estrogen (Premarin, 0.625 mg) plus medroxyprogesterone (Provera, 2.5 mg) or an identical placebo. Hormone therapy increased breast cancer significantly (by 26% over placebo) and caused higher rates of heart attacks (29%), strokes (41%) and blood clots (211%). These risks outweighed this therapy’s significant benefits in preventing osteoporotic fractures of the hip (decreased by 34%) and colon cancer (decreased by 36%).
Since July 2002,hundreds of talk shows and editorials across North America have discussed these results. Many doctors and medical groups have offered criticisms. However, no one has yet identified what I believe is most important.