Lifestyle appears to be a major factor in whether you develop prostate cancer. An excellent review of the world’s scientific research concludes: “Heart healthy equals prostate healthy . . . the best dietary advice for prostate cancer prevention or management seems to include: increasing fruits and vegetables, replacing refined carbohydrates with whole grains, reducing total and saturated fat, reducing overcooked meats and consuming a moderate amount of calories and reducing carbohydrates with a primary goal of obtaining and maintaining a healthy body weight” (BMC Medicine, January 8, 2015;13(3).
In North America, prostate cancer affects:
• 35 percent of men 70-80 years old,
• 70 percent of men over 80, and
• virtually 100 percent of men over 90.
In rural China, fewer than four percent of men over 90 have prostate cancer, while Chinese men who adopt the Western diet and lifestyle have the same high rates as North American men. The rural Chinese habits of a plant-based diet, low calorie intake and daily manual labor probably account for much of the difference.
Most North American men eat the typical western diet loaded with red and processed meat, sugared drinks, sugar-added and fried foods, do not exercise and gain an average of five pounds every decade. The typical Western diet appears to weaken your immunity and put you at increased risk for diabetes, heart attacks, strokes and various cancers including prostate cancer.
Red Meat and Fried Foods
Red meat is associated with increased risk both for prostate cancer (Cancer Epidemiology, Biomarkers & Prevention, 08/04/2015) and for advanced type of prostate cancer that can kill (Am J Clin Nutr, 2010, 91:712-721), possibly because of the heterocyclic amines produced during cooking (Cancer Sci, 2004 Apr;95(4):290-9). Fried foods have been associated with increased risk for prostate cancer (Prostate, 2013 Jun;73(9):960-9), and cooking any protein without water (frying, grilling, broiling and so forth) increases cancer risk because it causes carcinogens called Advanced Glycation Endproducts (AGEs) to form. When you cook with water, sugar binds to the water and is harmless. When you cook without water, sugar binds to protein and nucleic acids to form AGEs that are known carcinogens (Cancer Causes & Control, 2012, 23:405-420).
Foods rich in choline and lecithin (meat, eggs and dairy) are associated with increased risk for prostate cancer, possibly because these chemicals are converted by bacteria in your gut to TMAO, a chemical that can cause cancers. See Why I STILL Restrict Meat, Eggs and Milk. Perhaps the link between choline consumption and prostate cancer risk is only an association and has no cause and effect relationship at all. This is true of all studies that find associations but not cause-and-effect.
Fruits and Vegetables
Eating a diet rich in fruits and vegetables is associated with reduced risk for suffering prostate cancer (Int J Urol, 2012, 19:134-141 and Asian Pac J Cancer Prev, 2014, 15:5223-5227). Eating a plant-based diet lowered risk for obesity-related cancers, including prostate cancer (Cancer Causes & Control, January 6, 2015).
Limiting alcoholic drinks to no more than two per day for men and one per day for women was associated with reduced obesity-related cancers, and particularly breast, prostate, and colorectal cancers (Cancer Causes & Control, January 6, 2015). Data from the Nurses’ Health Study and the Health Professionals Follow-up Study show that small amounts of alcohol increase prostate cancer risk in smokers (British Medical Journal, August 18, 2015).
Consuming ten portions of tomatoes a week can lower the risk of prostate cancer (Cancer Epidemiology, Biomarkers and Prevention, July 13, 2014). Lycopene, an antioxidant found in tomatoes, lowered prostate cancer risk by 18 percent. Other sources of lycopene include apricots, guava, watermelon, papaya and grapefruit, although tomatoes have it in greater amounts.
No good data determines whether the amount of protein you eat affects prostate cancer risk. One recent study reported that low protein intake is associated with lower risk for prostate cancer in men 65 and younger, while in men older than 65, low protein intake was associated with a higher risk for cancer and death (Cell Metab, 2014, 19:407-417).
Lack of Exercise and Overweight
Lack of exercise and being overweight are associated with increased risk for the type of prostate cancer that kills (Cancer, June 2015 and Cancer Prevention Research, May 19, 2015). An extensive review shows that exercise is associated with a lowered risk for prostate cancer and its recurrence (Cancer Epidemiology, Biomarkers & Prevention, January 28, 2015).
High Blood Sugar Levels
Prostate cancer is associated with everything that raises blood sugar levels: metabolic syndrome (pre-diabetes), diabetes, inflammation, obesity and weight gain (Cancer Causes and Control, 05/14/2014), lack of exercise (Cancer Epidemiology, Biomarkers & Prevention, 04/02/2014), and lack of vitamin D. A high rise in blood sugar causes a marked increase in insulin and IGF-1, hormones that cause cells to multiply and grow to increase cancer risk. People who take in a lot of refined carbohydrates have high insulin and IGF-1 levels and are at increased risk for prostate cancer (Prostate, 2008, 68:11-19).
We do not know if the anti-diabetes drug, metformin, helps to prevent prostate cancer. Metformin lowers high blood sugar levels. In some studies, it reduced prostate cancer risk and death from prostate cancer in humans (J Clin Oncol, 2013, 31:3069-3075), while in other studies, it offered no protection at all (Prostate Cancer Prostatic Dis, 2013, 16:391-397).
Lack of Vitamin D
Scientists have not shown that high blood sugar levels cause prostate cancer, but they have shown that having high blood sugar levels is associated with increased prostate cancer risk. Vitamin D deficiency blocks insulin receptors to raise blood sugar levels and increase risk for diabetes. Men who have low blood levels of vitamin D are at increased risk for prostate cancer and specifically for the type of prostate cancer that kills (Clinical Cancer Research, May 1, 2014). Vitamin D plays several critical roles in how cells develop and grow. Vitamin D helps to regulate how stem cells change into prostate cells and the rate that normal cells turn into cancer cells. Adding vitamin D to prostate cells in a petri dish slows their rate of growth. Perhaps not having enough vitamin D can cause normal cells to become cancerous. Researchers found that almost all of 667 men referred for prostate biopsies because of high blood PSA tests or abnormal prostate exams had low levels of vitamin D. Their levels of hydroxy vitamin D were usually below 20ng/ml. Normal is 30 to 80. Furthermore, 44 percent of the men with prostate cancer had very low levels of vitamin D compared to 38 percent of those who tested negative. The lower the level of vitamin D, the more likely the cancer was to kill them.
Lifestyle Changes Help Men Who Already Have Prostate Cancer
A study from Harvard shows that men who have prostate cancer and adopt a heart-healthy, plant-based diet rich in vegetables, fruit, beans, fish and whole grains are far less likely to die from prostate cancer, compared to prostate cancer patients who continued to eat red meat, processed meat, eggs, potatoes, high-fat dairy products, butter, processed grains found in bakery products and pastas, snacks, sweets and desserts (Cancer Prevention Research, published online June 1, 2015). Researchers at Harvard Medical School followed more than a thousand men with early stage prostate cancer for a couple years and found that, compared to men who ate eggs only on rare occasions, those who ate two to five eggs a week had double the risk of the prostate cancer spreading through their bodies (Am J Clin Nutr, 2010 Mar;91(3):712-21). An earlier study came to the same conclusion (Cancer Prev Res (Phila), Dec 2011;4(12):2110-21). The Mediterranean diet based on fruits and vegetables prolongs the lives of men previously diagnosed with prostate cancer (European Urology, May 2014; 65(5): 887-894) and reduced risk for recurrence in men already diagnosed with prostate cancer (Int J Cancer, 2012, 131:201-210). Avoiding alcohol and overweight help to prevent prostate cancer recurrence (Cancer Causes & Control, January 6, 2015).