CHICAGO, July 6 (Reuters) - Soy protein, a supplement many doctors recommend as a substitute for hormone therapy for postmenopausal women, did not decrease bone loss or affect other symptoms in a study of Dutch women, researchers reported Tuesday. Naturally occurring compounds called isoflavones, which are found in soybeans, are thought to mimic estrogen compounds in hormone therapy. Some women want to avoid hormone therapy because recent studies have indicated that long-term use could raise the risk of stroke, dementia and some forms of cancer. In the new study, which followed 175 Dutch women for a year, half the participants...