Research shows that a plant-based diet may lower prostate cancer risk and slow its progression if diagnosed. Fruits and vegetables rich in lycopene (the bright red pigment found in tomatoes, watermelon, and pink grapefruit) may be especially beneficial. Men who consume two or more servings of tomato sauce per week have 23 percent less risk of prostate cancer, compared to those having tomato sauce less than once per month, according to data from the Harvard's Health Professionals Follow-Up Study. Cruciferous vegetables (such as broccoli, cabbage, and Brussels sprouts) also offer protection.

Milk and dairy products are linked to an increased prostate cancer risk due to the hormone insulin-like growth factor (IGF-I), saturated fat, and dairy calcium and protein. Red and processed meat and eggs are also associated with increased risk for prostate cancer.