Epidemiological studies have suggested many promising foods for prostate cancer prevention, such as soy and tomatoes. Soy consumption is believed to be one of the reasons for the low incidence in Asian countries. It is rich in phytoestrogens, which have been shown to reduce tumor size and decrease PSA secretion in animal studies. Tomatoes are rich in lycopene, an antioxidant that reduces the risk of the disease by 16% in people with a high intake compared to those with a low intake.