Several studies show that a high-plant diet such as a Mediterranean diet is associated with reduced risk for the type of prostate cancer than can kill you (The Journal of Urology, Aug 25, 2017) and if you already have prostate cancer, that diet is associated with reduced chance of dying from that disease (World J Urol, Jun 2017;35(6):867–874). Other studies show that replacing animal fats and proteins with those from plants is associated with reduced prostate cancer risk (JAMA Intern Med, 2013;173(14):1318-1326).
Almost all North American men will develop prostate cancer if they live long enough. Autopsy studies find prostate cancer in 80 percent of men in their seventies (Int J Cancer, November 15, 1977;20(5):680–8). Today, nearly 2.5 million men in the U.S. are living with a diagnosis of prostate cancer, but only a small percentage will die from it. More than 50 percent of North American men will develop prostate cancer by age 60 (J Natl Cancer Inst (2013) 105 (14):1050-1058) and five percent of men have it by age 30 (Int J Cancer, 2015 Oct 1; 137(7): 1749–1757). Unlike many other cancers, prostate cancer usually grows very slowly and does not kill the vast majority of men who have it.
A team of researchers from Harvard and UC-San Francisco conducted a comprehensive review of studies on dietary and lifestyle factors that appear to affect prostate cancer progression (World J Urol, 2017 Jun; 35(6): 867–874). The references listed below are among the many studies cited in this review.
Foods Associated with Reduced Prostate Cancer Risk
• Fruits and vegetables (J Natl Cancer Inst 2007;99:1200-1209; 2002;94:1648-1651). Most fruits and vegetables are rich sources of soluble fiber that is associated with reduced risk for prostate cancer (J Nutr, 2014 Apr 1;144(4):504–10). Yellow and orange vegetables such as carrots, pumpkin, sweet potatoes and winter squash contain carotenoids associated with reduced prostate cancer risk.
• Cruciferous vegetables contain isothiocyanates and indoles such as sulforaphane that are associated with reduced risk for prostate cancer (Int J Urol, 2012;19:134-141) and the aggressive type of prostate cancer (J Natl Cancer Inst, 2007;99:1200–1209). Examples include broccoli, cauliflower, cabbage, brussels sprouts, kale, mustard greens, radishes, bok choy and Swiss chard.
• Beans, mushrooms and seeds have antioxidants that help to prevent prostate cancer (Int J Cancer, 2008 Jun 2;123(4):927–32).
• The onion family including garlic, leeks, shallots, scallions, and chives contain organo-sulfur compounds with anti-cancer effects and are associated with reduced prostate cancer risk (Amer J of Clin Nutr, 2006;84:1027-1032).
• Berries such as strawberries, blackberries, blueberries, and raspberries have antioxidants that help protect your body from free radicals that can cause cancer (Nutr Cancer, 2013;65:793-801).
• Tomatoes are a rich source of the antioxidant lycopene, which has been shown in some studies to inhibit prostate cancer growth and spread (J Natl Cancer Inst, 2014;106(2):djt430). Several studies associate eating tomatoes with reduced risk for prostate cancer (J Natl Cancer Inst, 2002;94:391–398), and cooking increases their lycopene content (Exp Biol Med (Maywood), 2002;227:852-859).
• Tea, which contains antioxidant compounds called catechins, is associated with reduced risk for prostate cancer in some studies but not in others (Am J Epidemiol, 2008;167:71–77).
• Coffee is associated with a significant reduction in risk for the aggressive form of prostate cancer in several epidemiological studies (J Natl Cancer Inst, 2011;103:876–884), and in progression of prostate cancer in men who already have that diagnosis (Cancer Causes Control, 2013;24:1947–1954).
• Fish has mixed results in studies on prostate cancer risk. Several epidemiological studies show that men who eat fish regularly are at reduced risk for death from prostate cancer, while other studies show that there is no association between eating fish and risk of aggressive prostate cancer (Am J Clin Nutr, 2010;92:1223–1233). On the other hand, some studies show that men with high levels of omega-3 fatty acids from eating fish regularly are at increased risk of being diagnosed with prostate cancer (J Natl Cancer Inst, 2013;105:1132–1141).
Foods Associated with Increased Risk for Prostate Cancer
• Processed meats such as salami, bologna, sausage, bacon and hot dogs (Am J Epidemiol, 2009;170:1165–1177). The World Health Organization (WHO) has classified processed meat as carcinogenic to humans.
• All meats from mammals (Acta Oncol, 2005;44:277-281). Suggested but unproven causes include Neu5Gc and TMAO.
• Deep fried foods. Cooking at high temperatures without water forms heterocyclic amines that are associated with increased cancer risk (Nutr Cancer, Jul 17, 2009;61(4):437–46). When you fry without water, sugar binds to the protein in meat to form AGEs (advanced glycation endproducts that are known carcinogens (PLoS ONE, Nov 23, 2011;6(11):e27711) and are associated with increased prostate cancer risk (Nutr Cancer, May 2011;63(4):525–37).
Foods Possibly Associated with Increased Prostate Cancer Risk
• Eggs are a rich source of choline that can be converted by bacteria in your colon to TMAO that can increase risk for prostate and other cancers. In one study, men who ate 2.5 or more eggs per week were at increased risk for the aggressive form of prostate cancer, compared to those who ate less than half an egg per week (Am J Clin Nutr 2012;96:855-863). However, other studies have shown no association between eggs and prostate cancer (Asian Pac J Cancer Prev, 2012;13:4677–4681).
• Milk is a rich source of galactose, a sugar that turns on your immunity to cause inflammation to increase cancer risk (J Nutr, 2013;143:189-196; Nutr Metab (Lond), 2012;9:74). One study associated milk with increased risk for death from prostate cancer (Prostate, 2010;70:1054-1065).
• Poultry: most studies show that skinless poultry is not associated with risk of developing aggressive prostate cancer (Cancer Prev Res (Phila), 2011;4:2110–2121). However, eating a lot of poultry is associated with higher blood level of IGF-1 (insulin-like growth factor-1), which has been associated with increased risk for prostate cancer (Proc Nutr Soc, 2011:1-4).
Non-Food Risk Factors for Prostate Cancer
• Lack of vitamin D is associated with increased risk for cancer in general (Mol Cell Endocrinol, 2011;347:61-69) and prostate cancer specifically (Cancer Epidemiol Biomarkers Prev, 2014;23:1447-1449). The current recommendation is to keep your blood level of hydroxy vitamin D above 20 nmol/L.
• Being overweight is substantially associated with increased risk for developing localized and progressive prostate cancer (Ann Oncol, 2012 Jan 6;23(7):1665–71) and from dying from it if you already have it (Cancer Prev Res (Phila), 2011;4:486–501). Gaining weight after being diagnosed with prostate cancer is significantly associated with prostate cancer spread and death (Cancer Prev Res (Phila), 2011;4:544–551).
• Lack of exercise: Many studies show that men who exercise are far less likely to develop prostate cancer and those who exercise vigorously are protected from that disease even more. Exercising after being diagnosed with prostate cancer is associated with reduced recurrence (Cancer Epidemiol Biomark Prev, 2015;24:57–64) and reduced death from prostate cancer (J Clin Oncol, 2011;29:726–732). Vigorous exercise strengthens the heart and lungs, increases muscle strength, reduces body fat and helps to improve mood in cancer survivors (Support Care Cancer, 2012;20:221–233).
• Smoking increases risk of prostate cancer, aggressive prostate cancer (JAMA, 2011;305:2548–2555) and death from prostate cancer (Eur Urol, 2015;68:949–956).
• Alcohol: Taking in more than two drinks per day is associated with increased prostate cancer risk (Br J Cancer, 2015 Feb 3; 112(3):580–593; Eur J Cancer Prev, Jul 2012;21(4):350–9).
You can help to prevent prostate cancer with the same lifestyle changes used to prevent and treat heart attacks. More and more studies are associating prostate cancer with the same risk factors as those for heart attacks: unhealthful diet, overweight, lack of exercise, lack of vitamin D, high blood sugar levels, smoking and excess alcohol intake. The same life style changes that are associated with decreased risk for prostate cancer are also associated with increased survival and freedom from spread of the cancer if you already have it. See Lifestyle After Prostate Cancer Diagnosis