Extensive data show that the typical western diet, obesity, and lack of exercise are associated with increased risk for prostate cancer. Recent studies now show that intense exercise (JAMA Oncol, Aug 2021;7(10):1487-1495) and an anti-inflammatory diet (Cancer Epidemiology, Biomarkers & Prevention, Nov 2021) help to reduce markers for prostate cancer progression in men who already have prostate cancer.
The Importance of Exercise
Men undergoing active surveillance for the treatment of prostate cancer participated in thrice-weekly supervised aerobic exercise on treadmills, using high-intensity interval training at 85-95 percent of their peak oxygen consumption or VO2max (JAMA Oncol, Aug 2021;7(10):1487-1495). After 12 weeks, they had a significant reduction in growth of:
• prostate cancer cell line LNCaP, a marker of prostate cancer growth
• prostate specific antigen (PSA) and prostate-specific antigen velocity, markers of cancer spread.
They also had improved peak oxygen consumption to show significantly increased fitness levels. The control group had maintained their normal exercise levels.
Lack of exercise and being overweight are associated with increased risk for the type of prostate cancer that kills (Cancer, June 2015; 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). See Exercise Should Be Part of the Treatment for Cancer.
Diet and Weight Control
Researchers at the Cleveland Clinic screened 76,685 men, ages 55 and 74, for prostate cancer and then monitored them for up to 13 years (Cancer Epidemiology, Biomarkers & Prevention, Nov, 2021). Among these participants, 173 died of their of prostate cancer. The median time between baseline sampling and death of those who died from prostate cancer was 12 years. Researchers can tell what a person has eaten over the long haul by measuring certain metabolites that are produced in the body from specific foods that they ate. In this study, the men with high blood levels of phenylacetylglutamine at the start of the study were 2.5 times more likely to die of prostate cancer than those with the lowest levels. Those with high choline or betaine levels had almost double the risk of dying from prostate cancer. These metabolites are found in higher levels in meat and other foods from animals.
Most North American men eat the typical Western diet loaded with red meat and processed meats, sugared drinks, sugar-added foods and fried foods, and gain an average of five pounds every decade. The typical Western diet appears to weaken your immune system and puts you at increased risk for diabetes, heart attacks, strokes and various cancers including prostate cancer.
- Red Meat and Fried Foods: Red meat has been associated with increased risk both for prostate cancer (Cancer Epidemiology, Biomarkers & Prevention, Aug 4, 2015) and for the advanced type of prostate cancer that can kill (Am J Clin Nutr, 2010, 91:712-721), possibly because of the heterocyclic amines (HCAs) 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, but when you cook without water, sugar binds to protein and nucleic acids to form AGEs (Cancer Causes & Control, 2012, 23:405-420).
- Choline, Lecithin, and TMAO: 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. 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. Many studies show that people with elevated levels of TMAO are at markedly increased risk for heart attacks, strokes and nerve damage, and just about every risk factor for a heart attack is also a risk factor for prostate cancer. The main cause of death in prostate cancer patients is a heart attack; see Prostate Cancer and Heart Attacks Share Lifestyle Factors
- Eat Lots of Vegetables and Fruits: Eating a diet that includes lots of fruits and vegetables is associated with reduced risk for suffering prostate cancer (Int J Urol, 2012, 19:134-141; 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). 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.
- Protein: No good data has determined 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).
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 even small amounts of alcohol increase prostate cancer risk in smokers (British Medical Journal, August 18, 2015). See Alcohol At Any Dose Can Increase Cancer Risk.
High Blood Sugar Levels
Prostate cancer is associated with everything that raises blood sugar levels: metabolic syndrome (pre-diabetes), diabetes, inflammation, obesity, 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 metformin, an anti-diabetes drug, 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
Vitamin D deficiency blocks insulin receptors to raise blood sugar levels and increase risk for diabetes. 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. 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 20 ng/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.
Most of the risk factors for prostate cancer are also risk factors for heart attacks. Evidence is now accumulating that all the rules for preventing heart attacks may also help to prevent spread of prostate cancer in men who already have that diagnosis. I believe that every man should try to reduce his risk for both prostate cancer and heart attacks these lifestyle changes.
Lifestyle Changes Do Help to Prevent Cancers and Heart Attacks
Healthful Lifestyles to Prevent Cancer