Gynaecology An exhaustive epidemiological study by F. Gagnon based on 3,280 Canadian nuns, which found no cancers of the uterine cervix, confirming Rigoni-Stern’s 1842 observation that cervical cancer is linked to sexual activity.
Neurology A study in which linguistic ability in early life and cognitive function and Alzheimer’s disease in late life were compared in a religious order—the School Sisters of Notre Dame
After his death, while I was studying for my Batchelor of Visual Arts in textiles, which I focused on Alzheimer's disease, I read Aging with Grace: What the Nun Study Teaches Us about Leading Longer, Healthier, and More Meaningful Lives by David Snowdon.
Lon White, MD, MPH, a neuroepidemiologist, and his team from the University of Hawaii and the Veterans Affairs-affiliated Pacific Health Research and Education Institute analyzed studies involving more than 1,100 people who had participated in the Nun Study or the Honolulu-Asia Aging Study.
Consider the famous Nun Study: Although it had a much smaller sample than the Lancet study, it started when the nuns, all living in similar conditions with similar diets, were 22 and followed them until death.
A particularly powerful study along those lines is called either the Nun study or the Religious Orders study, in which individuals have been in a known and relatively controlled environment their entire lives.
However, contrary to expectations from Snowden et al.'s (1996) nun study, AH 4 (1) test scores declined slightly less rapidly across decade samples who currently have lower Mill Hill scores and so certainly had lower youthful AH 4 (1) test scores.