Men who have sex with themselves frequently in their 20s and 30s have a higher chance of developing prostrate cancer.
Researchers at the University of Nottingham surveyed 800 men, about half of whom had suffered prostate cancer, and found that the more sexual activity the had engaged in as young adults, the more likely they were to have been stricken with the disease. While a higher rate of intercourse did contribute to this discrepancy, most of the difference was attributed to self-love. (Source)
Using logic, Anne Hathaway is going to give me prostrate cancer.