Diet, Exercise & Prostate Cancer Prevention

By Gene Bruno, MS, MHS (Dean of Academics, Huntington College of Health Sciences)

Arguably the most effective way to reduce the risk of prostate cancer is to make lifestyle changes. According to the American Cancer Society,i for most Americans who do not use tobacco, the most important cancer risk factors that can be changed are body weight, diet, and physical activity.

One-third of all cancer deaths in the United States each year are linked to diet and physical activity, including being overweight or obese, while another third is caused by tobacco products. This article will examine the relationship between diet, exercise and prostate cancer prevention.

Diet and prostate cancer prevention

To help prevent all types of cancers, the American Cancer Society (ACS) recommends that individuals consume a healthy diet, with an emphasis on plant foods. Specifically, people should eat at least 2.5 cups of vegetables and fruits each day, and choose whole grains instead of refined grain products. ASC sensibly advises that people choose foods and beverages in amounts that help achieve and maintain a healthy weight. ACS also recommends limiting the consumption of processed meat and red meat, as well as limiting the consumption of alcoholic beverages (no more than 1 drink per day for women or 2 per day for men).ii In general, these recommendations are consistent with research on dietary practices for the prevention of prostate cancer as discussed below.

High-fat

Diets high in fat are associated with increased risk of prostate cancer. In a multicenter study,iii researchers compared the diets of 194 patients with newly diagnosed prostate cancer to those of 317 healthy patients. What they found was that there was an increase in prostate cancer associated with diets high in fat. A studyiv conducted in 12 cities in China also found that dietary fat, both saturated and unsaturated, are associated with an increased risk for prostate cancer. Likewise, research in Greece found that seed oils (e.g., safflower, etc.), were significantly associated with prostate cancer risk, while butter and margarine had a lesser association. Olive oil was not associated with prostate cancer risk.v A studyvi in the United States linked greater consumption of fat from animal sources to increased risk for prostate cancer among American blacks, and to advanced prostate cancer among American blacks and whites. Research concluded, “A reduction of fat from animal sources in the diet could lead to decreased incidence and mortality rates for prostate cancer, particularly among American blacks.” The results of a joint U.S./Canadian studyvii suggested that a high intake of omega-6 fatty acids, (typically from vegetable oils), promoted inflammation might be associated with increased prostate cancer risk.

Dairy

There is a strong association between the consumption of dairy products and increased prostate cancer risk. A large studyviii conducted in ten European countries found that a high intake of dairy-based protein was associated with an increased risk of prostate cancer. In fact, researchers estimated a 32% higher risk of prostate cancer from increased consumption of dairy proteins. Calcium from dairy products was also positively associated with risk, but not calcium from other foods—suggesting that dairy foods rather than calcium were the culprit.ix Another large studyx conducted in the United States and Canada found that dietary calcium from dairy products increased the risk of low-grade prostate cancer but reduced the risk of high-grade cancer.

This relationship with dairy foods and prostate cancer was again seen in a large study conducted by the National Cancer Institute.xi The results showed that a greater dietary intake of calcium and dairy products, particularly low-fat dairy products, may be modestly associated with increased risks for nonaggressive prostate cancer, but was unrelated to aggressive disease. In case you’re wondering why the low-fat dairy products would pose a greater risk, the reason probably has to do with the fact that with less fat there is a higher percentage of dairy protein, one of the culprits. A French studyxii verified the relationship between dairy product consumption and prostate cancer risk. They also found that the risk was not associated with the calcium content, “and may be related to some other component.” Research in Greece also found that milk and dairy product consumption was associated with risk for prostate cancer.xiii

Vegetables

Research among diverse populations in the United States and Canada found that the consumption of legumes (i.e., beans, especially soy foods), significantly reduced the risk of prostate cancer. The consumption of yellow-orange and cruciferous vegetables (e.g., broccoli, cabbage, Brussels sprouts, etc.), was also shown to reduce prostate cancer risk.xiv Another studyxv of almost 2000 men found that there was a decreased prostate cancer risk with increasing intakes of vitamin C-rich vegetables, including bell peppers and broccoli. Likewise, Canadian researchers demonstrated that increasing dietary consumption of green vegetables, tomatoes, beans/lentils/nuts, and cruciferous vegetables also decreased the risk of prostate cancer.xvi Still other researchxvii found that diets providing substantial amounts of tomatoes/tomato products and garlic may protect against prostate cancer. Research in Greece also found that cooked tomatoes, and to a lesser extent raw tomatoes, were associated with a reduced risk for prostate cancer.xviii

Well-done meat

When meat is cooked at high-temperatures for a long period of time, it forms certain compounds that can increase the risk of prostate cancer. This was seen in a study where very well done meat was strongly associated with prostate cancer risk.xix

Apples

Researchers studying the diets of people in Italy found that those who ate at least one apple per day had a reduced risk for prostate cancer.xx Maybe an apple a day really does keep the doctor away—or in this case, the oncologist.

Glycemic index and glycemic load

Glycemic index (GI) is a numerical system of measuring how fast a carbohydrate triggers a rise in circulating blood glucose, and glycemic load (GL) measures a rise in glucose from an individual serving size of food. In either case, the higher the number, the greater the blood glucose response. So a low GI/GL food will cause a small rise, while a high GI/GL food will trigger a dramatic spike. Carbohydrate foods with more fiber are likely to have a lower GI/GL. The fiber causes the food to break down more slowly in the digestive system, and also slows the absorption of any sugars it contains. The result is a slower increase in blood glucose levels. By contrast, simple or refined carbohydrates such as most desserts or white bread/white pasta, break down rapidly and yield their sugars quickly, so they will generally be higher on the GI/GL.xxi

This is an important consideration in prostate cancer, since the higher the rise in blood glucose, the more insulin will be secreted to deal with it, and insulin has been implicated as a risk factor for several cancers, including that of the prostate. Consequently, it makes sense that researchers conducted a study examining the relationship between GI/GL and prostate cancer risk. They found that with increasing levels of GI/GL, there was a corresponding increase in risk for prostate cancer.xxii

Exercise and prostate cancer prevention

As with dietary recommendations, the American Cancer Society (ACS), also has exercise recommendations to help prevent all types of cancers. Specifically, ACS advises that adults should engage in at least 150 minutes of moderate intensity or 75 minutes of vigorous intensity activity each week, or an equivalent combination, preferably spread throughout the week. Likewise, children and adolescents should engage in at least 1 hour of moderate or vigorous intensity activity each day, with vigorous intensity activity occurring at least 3 days each week. Sedentary behavior such as sitting, lying down, watching television, or other forms of screen-based entertainment should be limited. ACS’s bottom line is to do some physical activity.xxiii These recommendations for an active lifestyle make good sense and can be of benefit to individuals with and without prostate cancer.

A large European studyxxiv examined the association between risk of prostate cancer and physical activity. The results showed that a higher level of occupational physical activity was associated with lower risk of advanced stage prostate cancer. A reviewxxv of several studies found that heavy occupational physical activity and leisure-time physical activity seemed to reduce the risk of advanced prostate cancers. Another scientific reviewxxvi indicated that 22 studies have shown physical activity to be associated with some reduced risk of prostate cancer. Other research has shown similar results.xxvii Additionally, a studyxxviii in Malaysia found that men with a past history of not engaging with any physical activities at the age of 45 to 54 years old increased risk of prostate cancer by approximately three fold.

References

i Kushi LH, Doyle C, McCullough M, Rock CL, Demark-Wahnefried W, Bandera EV, Gapstur S, Patel AV, Andrews K, Gansler T; American Cancer Society 2010 Nutrition and Physical Activity Guidelines Advisory Committee. American Cancer Society Guidelines on nutrition and physical activity for cancer prevention: reducing the risk of cancer with healthy food choices and physical activity. CA Cancer J Clin. 2012 Jan-Feb;62(1):30-67.

ii Kushi LH, Doyle C, McCullough M, Rock CL, Demark-Wahnefried W, Bandera EV, Gapstur S, Patel AV, Andrews K, Gansler T; American Cancer Society 2010 Nutrition and Physical Activity Guidelines Advisory Committee. American Cancer Society Guidelines on nutrition and physical activity for cancer prevention: reducing the risk of cancer with healthy food choices and physical activity. CA Cancer J Clin. 2012 Jan-Feb;62(1):30-67.

iii Salem S, Salahi M, Mohseni M, Ahmadi H, Mehrsai A, Jahani Y, Pourmand G. Major dietary factors and prostate cancer risk: a prospective multicenter case-control study. Nutr Cancer. 2011;63(1):21-7.

iv Lee MM, Wang RT, Hsing AW, Gu FL, Wang T, Spitz M. Case-control study of diet and prostate cancer in China. Cancer Causes Control. 1998 Dec;9(6):545-52.

v Tzonou A, Signorello LB, Lagiou P, Wuu J, Trichopoulos D, Trichopoulou A. Diet and cancer of the prostate: a case-control study in Greece. Int J Cancer. 1999 Mar 1;80(5):704-8.

vi Hayes RB, Ziegler RG, Gridley G, et al. Dietary factors and risks for prostate cancer among blacks and whites in the United States. Cancer Epidemiol Biomarkers Prev. 1999 Jan;8(1):25-34.

vii Kristal AR, Arnold KB, Neuhouser ML, Goodman P, Platz EA, Albanes D, Thompson IM. Diet, supplement use, and prostate cancer risk: results from the prostate cancer prevention trial. Am J Epidemiol. 2010 Sep 1;172(5):566-77.

viii Gonzalez CA, Riboli E. Diet and cancer prevention: Contributions from the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Eur J Cancer. 2010 Sep;46(14):2555-62.

ix Allen NE, Key TJ, Appleby PN, et al. Animal foods, protein, calcium and prostate cancer risk: the European Prospective Investigation into Cancer and Nutrition. Br J Cancer. 2008 May 6;98(9):1574-81.

x Kristal AR, Arnold KB, Neuhouser ML, Goodman P, Platz EA, Albanes D, Thompson IM. Diet, supplement use, and prostate cancer risk: results from the prostate cancer prevention trial. Am J Epidemiol. 2010 Sep 1;172(5):566-77.

xi Ahn J, Albanes D, Peters U, Schatzkin A, Lim U, Freedman M, Chatterjee N, Andriole GL, Leitzmann MF, Hayes RB; Prostate, Lung, Colorectal, and Ovarian Trial Project Team. Dairy products, calcium intake, and risk of prostate cancer in the prostate, lung, colorectal, and ovarian cancer screening trial. Cancer Epidemiol Biomarkers Prev. 2007 Dec;16(12):2623-30.

xii Kesse E, Bertrais S, Astorg P, Jaouen A, Arnault N, Galan P, Hercberg S. Dairy products, calcium and phosphorus intake, and the risk of prostate cancer: results of the French prospective SU.VI.MAX (Supplémentation en Vitamines et Minéraux Antioxydants) study. Br J Nutr. 2006 Mar;95(3):539-45.

xiii Tzonou A, Signorello LB, Lagiou P, Wuu J, Trichopoulos D, Trichopoulou A. Diet and cancer of the prostate: a case-control study in Greece. Int J Cancer. 1999 Mar 1;80(5):704-8.

xiv Kolonel LN, Hankin JH, Whittemore AS, et al. Vegetables, fruits, legumes and prostate cancer: a multiethnic case-control study. Cancer Epidemiol Biomarkers Prev. 2000 Aug;9(8):795-804.

xv Ambrosini GL, de Klerk NH, Fritschi L, Mackerras D, Musk B. Fruit, vegetable, vitamin A intakes, and prostate cancer risk. Prostate Cancer Prostatic Dis. 2008;11(1):61-6.

xvi Jain MG, Hislop GT, Howe GR, Ghadirian P. Plant foods, antioxidants, and prostate cancer risk: findings from case-control studies in Canada. Nutr Cancer. 1999;34(2):173-84.

xvii Salem S, Salahi M, Mohseni M, Ahmadi H, Mehrsai A, Jahani Y, Pourmand G. Major dietary factors and prostate cancer risk: a prospective multicenter case-control study. Nutr Cancer. 2011;63(1):21-7.

xviii Tzonou A, Signorello LB, Lagiou P, Wuu J, Trichopoulos D, Trichopoulou A. Diet and cancer of the prostate: a case-control study in Greece. Int J Cancer. 1999 Mar 1;80(5):704-8.

xix Cross AJ, Peters U, Kirsh VA, Andriole GL, Reding D, Hayes RB, Sinha R. A prospective study of meat and meat mutagens and prostate cancer risk. Cancer Res. 2005 Dec 15;65(24):11779-84.

xx Gallus S, Talamini R, Giacosa A, Montella M, Ramazzotti V, Franceschi S, Negri E, La Vecchia C. Does an apple a day keep the oncologist away? Ann Oncol. 2005 Nov;16(11):1841-4.

xxi Bruno G. A Guide to Complementary Treatments for Diabetes. Garden City Park, NY: Square One Publishers; 2009.

xxii Augustin LS, Galeone C, Dal Maso L, et al. Glycemic index, glycemic load and risk of prostate cancer. Int J Cancer. 2004 Nov 10;112(3):446-50.

xxiii Kushi LH, Doyle C, McCullough M, Rock CL, Demark-Wahnefried W, Bandera EV, Gapstur S, Patel AV, Andrews K, Gansler T; American Cancer Society 2010 Nutrition and Physical Activity Guidelines Advisory Committee. American Cancer Society Guidelines on nutrition and physical activity for cancer prevention: reducing the risk of cancer with healthy food choices and physical activity. CA Cancer J Clin. 2012 Jan-Feb;62(1):30-67.

xxiv Johnsen NF, Tjønneland A, Thomsen BL, et al. Physical activity and risk of prostate cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Int J Cancer. 2009 Aug 15;125(4):902-8.

xxv Anzuini F, Battistella A, Izzotti A. Physical activity and cancer prevention: a review of current evidence and biological mechanisms. J Prev Med Hyg. 2011 Dec;52(4):174-80.

xxvi Young-McCaughan S. Potential for prostate cancer prevention through physical activity. World J Urol. 2012 Apr;30(2):167-79.

xxvii Liu Y, Hu F, Li D, Wang F, Zhu L, Chen W, Ge J, An R, Zhao Y. Does physical activity reduce the risk of prostate cancer? A systematic review and meta-analysis. Eur Urol. 2011 Nov;60(5):1029-44.

xxviii Shahar S, Shafurah S, Hasan Shaari NS, Rajikan R, Rajab NF, Golkhalkhali B, Zainuddin ZM. Roles of diet, lifetime physical activity and oxidative DNA damage in the occurrence of prostate cancer among men in Klang Valley, Malaysia. Asian Pac J Cancer Prev. 2011;12(3):605-11.