Home Health Diet and Prostate Cancer Risk

Diet and Prostate Cancer Risk

By, Robert A. Wascher, MD, FACS

Updated:  05/31/2009

The information in this column is intended for informational purposes only, and does not constitute medical advice or recommendations by the author. Please consult with your physician before making any lifestyle or medication changes, or if you have any other concerns regarding your health.

DIET & PROSTATE CANCER RISK

The prostate gland is a walnut-sized gland that is attached to the bottom of the bladder. The prostate gland wraps around the male urethra as it arises from the bladder, and several ducts that run between the prostate gland and the urethra allow the pro-static secretions to be expelled into the urethra at the time of ejaculation. These prostatic secretions, which constitute about 20 percent of the volume of semen, help to create the optimal chemical environment for sperm to thrive and migrate within the female genital tract, thereby enhancing sperm function. 

In 2009, an estimated 192,000 new cases of prostate cancer will be diagnosed, and approximately 27,000 men will die of this disease in the same year. Prostate cancer is the most common non-skin cancer that occurs in men, and is the second most common cause of cancer death in men. Prostate cancer afflicts 1 out of every 6 American men during their lifetimes, and accounts for 25 percent of all cancer diagnoses in men (similar to the percentage of breast cancer cases among all cancer cases diagnosed in women). As with the great majority of breast cancer cases, most prostate cancers appear to be stimulated to grow and spread by sex hormones produced by the gonads (and, specifically, by testosterone and other androgens produced by the testes, and by other tissues in the body). 

There continues to be considerable debate about the impact of diet on prostate cancer risk, as a result of the contradictory conclusions of most epidemiological research studies regarding dietary factors and cancer risk, including prostate cancer (which is, in turn, a reflection of the relatively low scientific power of dietary survey-based studies, in general). Now, a large new prospective European clinical study has raised the possibility that the level of some dietary nutrients (isoflavones) in the blood may actually have an impact on prostate cancer risk. This study’s findings appear in the current volume of the British Journal of Cancer.

The patient volunteers in this particular study were part of a huge and ongoing prospective clinical research study, the European Prospective Investigation into Cancer and Nutrition study (EPIC study). Among the approximately 500,000 participants in the EPIC study, 950 men who were newly diagnosed with prostate cancer during the course of the study and 1,042 men who had no evidence of prostate cancer were evaluated for this particular prostate cancer sub-study. 

Isoflavones belong to a group of compounds referred to as phytoestrogens, which are found in certain foods. Phytoestrogens are substances found in certain edible plants, and are known to have weak estrogen-like effects (estrogen is the dominant female sex hormone). Soybeans, and soybean-derived soy proteins, represent the richest source of dietary isoflavones, although some other types of beans, nuts, fruits and vegetables contain low concentrations of isoflavones.  Lignans are another group of natural plant-based compounds that are considered to be phytoestrogens. Lignans are found in flax seeds, whole wheat flour, tea, some fruits, and other cereal grains.

In this prostate cancer prevention study, all of the patient volunteers had their blood tested for phytoestrogens at the time that they entered into the study. An especially interesting, and important, aspect of this study is that blood levels of isoflavones and lignans were tested in all of these 1,992 men, and before prostate cancer was diagnosed in the 950 men who were diagnosed with this form of cancer during the course of this study. Additionally, all of the study participants completed the usual dietary and general health surveys that are commonly used in epidemiological studies.  Thus, this particular cancer prevention study relied not only on subjective and bias-prone dietary surveys, but also upon objective measurements of isoflavone and lignan concentrations in the blood of all of these men.

While prostate cancer risk did not appear to vary with the concentration of lignans in the blood, the concentration of the isoflavone phytoestrogen genistein in the blood did, in fact, correlate with prostate cancer risk. The results of this study revealed that high serum concentrations of genistein were associated with a 26 percent relative reduction in the risk of developing prostate cancer. 

This study builds upon a previous Japanese study, which also measured phytoestrogen levels in the blood, and which reported a decrease in prostate cancer risk with high blood levels of genistein, although this observation, in the Japanese study, did not quite reach the level of statistical significance that is needed to scientifically validate such research findings. (The EPIC Study’s findings regarding genistein and prostate cancer risk did, however, meet this “statistically significant” threshold.)

In summary, therefore, this innovative prospective clinical research study identified an apparent significant reduction in the risk of developing prostate cancer among older men who had high levels of the isoflavone genistein circulating in their blood. As phytoestrogens are absorbed in the GI tract from plants containing high concentrations of these compounds, and as clinical studies based solely upon dietary surveys are notoriously inaccurate, this particular study’s direct measurement of phytoestrogen levels in the blood of its patient volunteers is a critically important innovation, and considerably increases the likelihood that the findings of this study are clinically significantly.

I will have much more to say, dear readers, about diet and prostate cancer prevention, as well as many other clinical evidence-based lifestyle and dietary strategies to reduce your risk of developing all of the top ten cancer killers, in my forthcoming book, “A Cancer Prevention Guide for the Human Race,” which should be available in the spring of 2010.

Disclaimer: As always, my advice to readers is to seek the advice of your physician before making any significant changes in medications, diet, or level of physical activity

Dr. Wascher is an oncologic surgeon, a professor of surgery, a widely published author, and a Surgical Oncologist at the Kaiser Permanente healthcare system in Orange County, California

(Anticipated Publication Date: March 2010)

(Click image for interview with Dr. Wascher)

Send your feedback to Dr. Wascher at:  

rwascher@doctorwascher.net

Dr. Wascher’s Biography

Links to Other Health & Wellness Sites

http://doctorwascher.com

Copyright 2009

Robert A. Wascher, MD, FACS

All rights reserved

Dr. Wascher’s Archives:

5-24-2009: Diabetes, Glucose Control & Death

5-17-2009: Drug Company Marketing & Physician Prescribing Bias

5-10-2009: Hemorrhoids & Surgery

5-3-2009: Statin Drugs & Blood Clots (Thromboembolism)

4-26-2009: Are We Really Losing the War on Cancer?

4-19-2009:  Exercise in Middle Age & Risk of Death

4-12-2009: Can Chronic Stress Harm Your Heart?

4-5-2009: Does PSA Testing for Prostate Cancer Save Lives?

3-22-2009: CABG Surgery vs. PCI in Diabetics with Coronary Artery Disease; Sweetened Beverages and Coronary Artery Disease

3-15-2009: Depression, Stress, Anger & Heart Disease

3-8-2009: Coronary Artery Disease: CABG vs. Stents?; Swimming Lessons & Drowning Risk in Children

3-1-2009: Aspirin & Colorectal Cancer Prevention; Fish Oil & Respiratory Infections in Children

2-22-2009: Health Differences Between Americans & Europeans; Lycopene & Prostate Cancer

2-15-2009: Statin Drugs & Death Rates; Physical Activity, Breast Cancer & Sex Hormones

2-8-2009: Hormone Replacement Therapy (HRT) & Breast Cancer; Stool DNA Testing & Cancer of the Colon & Rectum

2-1-2009:  Obesity and the Complications of Diverticulosis (Diverticulitis & Bleeding); Obesity, Weight Loss & Urinary Incontinence

1-25-2009: Prostate Cancer, Fatigue & Exercise; Does your Surgeon “Warm-up” Before Surgery?

1-18-2009: Cancer and Vitamins; Teenagers, MySpace and Risky Behaviors

 Exercise Reverses Some Effects of Fatty Meals; Vitamin C and Blood Pressure

1-4-2009: Secondhand Smoke & Heart Attack Risk; Poor Physical Fitness During Childhood & Heart Disease Risk During Adulthood

12-28-2008: Stress & Your Risk of Heart Attack; Vitamin D & the Prevention of Colon & Rectal Polyps

12-21-2008: Breast Cancer Incidence & Hormone Replacement Therapy; Circumcision & the Risk of HPV & HIV Infection

12-14-2008: Vitamin E, Vitamin C and Selenium Do Not Prevent Cancer; Postscript: A Possible Cure for Down’s Syndrome

12-7-2008: Generic vs. Brand-Name Drugs, Stress & Breast Cancer Survival

11-30-2008:   A Possible Cure for Down’s Syndrome?; Smoking & Cognitive Decline; Calcium & Vitamin D & Breast Cancer Risk

11-23-2008:  Breast Cancer & Fish Oil; Lymphedema after Breast Cancer Treatment; Vasectomy & Prostate Cancer Risk

11-16-2008:  Vitamin E & Vitamin C: No Impact on Cardiovascular Disease Risk; Does Lack of Sleep Increase Stroke & Heart Attack Risk in Hypertensive Patients?

11-9-2008:  Statins Cut Heart Attack Risk Even with Normal Cholesterol Levels; Statins & PSA Level

11-2-2008:  Radiation Treatment of Prostate Cancer & Second Cancers; Sexual Content on TV & Teen Pregnancy Risk

10-26-2008:  Smoking & Quality of Life

10-19-2008:  Agent Orange & Prostate Cancer

10-12-2008:  Pomegranate Juice & Prostate Cancer

10-5-2008:  Central Obesity & Dementia; Diet, Vitamin D, Calcium, & Colon Cancer

9-28-2008:  Publication & Citation Bias in Favor of Industry-Funded Research?

9-21-2008:  Does Tylenol® (Acetaminophen) Cause Asthma?

9-14-208:   Arthroscopic Knee Surgery- No Better than Placebo?; A Healthy Lifestyle Prevents Stroke

8-23-2008:  Alcohol Abuse Before & After Military Deployment; Running & Age; Running & Your Testicles

8-12-2008:  Green Tea & Diabetes; Breastfeeding & Adult Cholesterol Levels; Fish Oil & Senile Macular Degeneration

8-3-2008:   Exercise & Weight Loss; Green Tea, Folic Acid & Breast Cancer Risk; Foreign Language Interpreters & ICU Patients

7-26-2008:  Viagra & Sexual Function in Women; Patient-Reported Adverse Hospital Events; Curcumin & Pancreatic Cancer

7-13-2008:  Erectile Dysfunction & Frequency of Sex; Muscle Strength & Mortality in Men; Cryoablation for Prostate Cancer

7-6-2008:  Sleep, Melatonin & Breast Cancer Risk; Mediterranean Diet & Cancer Risk; New Treatment for Varicose Veins

6-29-2008:  Bone Marrow Stem Cells & Liver Failure; Vitamin D & Colorectal Cancer Survival; Green Tea & Colorectal Cancer

6-22-2008:  Obesity, Lifestyle & Heart Disease; Effects of Lifestyle & Nutrition on Prostate Cancer; Ginkgo Biloba, Ulcerative Colitis & Colorectal Cancer

6-15-2008:  Preventable Deaths after Coronary Artery Bypass Graft (CABG) Surgery; Green Tea & Colorectal Cancer; Attention-Deficit/Hyperactivity Disorder (ADHD) & St. John’s Wort

6-8-2008:  Vitamin D & Prostate Cancer Risk; Radiofrequency Ablation (RFA) of Kidney (Renal) Cancer; Antisense Telomerase & Cancer

6-2-2008:  Acute Coronary Syndrome- Do You Know the Symptoms?; Green Tea & Lung Cancer; Episiotomy & Subsequent Deliveries- An Unkind Cut

5-25-2008:  Early Childhood Screening Predicts Later Behavioral Problems; Psychiatric Disorders Among Parents of Autistic Children; Social & Psychiatric Profiles of Young Adults Born Prematurely

5-18-2008:  Can Statins Reverse Coronary Artery Disease?; Does Breast Ultrasound Improve Breast Cancer Detection?; Preventive Care Services at Veterans Administration (VA) Medical Centers

5-11-2008:  Smoking Cessation & Risk of Death; Childhood Traumas & Adult Suicide Risk; “White Coat Hypertension” & Risk of Cardiovascular Disease

5-4-2008:  Super-Size Me: Fast Food’s Effects on Your Liver; Exercise, Weight & Coronary Artery Disease; Contamination of Surgical Instruments in the Operating Room

4-27-2008:  Stents vs. Bypass Surgery for Coronary Artery Disease; The “DASH” Hypertension Diet & Cardiovascular Disease Prevention; Testosterone Therapy for Women with Decreased Sexual Desire & Function

4-20-2008:  BRCA Breast Cancer Mutations & MRI Scans; Bladder Cancer Prevention with Broccoli?; Diabetes: Risk of Death Due to Heart Attack & Stroke

4-13-2008:  Breast Cancer Recurrence & Hormone Replacement Therapy (HRT); Carotid Artery Disease: Surgery vs. Stents?; Statin Drugs & Cancer Prevention

4-6-2008:  Human Papilloma Virus (HPV), Pap Smear Results & Cervical Cancer; Human Papilloma Virus (HPV) Infection & Oral Cancer; Hormone Replacement Therapy (HRT) & the Risk of Gastroesophageal Reflux Disorder (GERD)

3-30-2008:  Abdominal Obesity & the Risk of Death in Women; Folic Acid Pretreatment & Heart Attacks; Pancreatic Cancer Regression after Injections of Bacteria

3-23-2008:  Age of Transfused Blood & Risk of Complications after Surgery; Obesity, Blood Pressure & Heart Size in Children

3-16-2008:  Benefits of a Full Drug Coverage Plan for Medicare Patients?; Parent-Teen Conversations about Sex; Soy (Genistein) & Prostate Cancer

3-9-2008:  Flat Colorectal Adenomas & Cancer; Health Risks after Stopping Hormone Replacement Therapy (HRT); Television, Children & Obesity 

3-2-2008:  Medication & Risk of Death After Heart Attack; Hormone Replacement Therapy (HRT) & Mammogram Results; Selenium: Cancer, Heart Disease & Death

2-23-2008:  Universal Healthcare Insurance Study; Glucosamine & Arthritis

2-17-2008:  Exceptional Longevity in Men; Testosterone & Risk of Prostate Cancer; Smoking & Pre-malignant Colorectal Polyps

2-10-2008:  Thrombus Aspiration from Coronary Arteries; Intensive Management of Diabetes & Death; Possible Cure for Down’s Syndrome?

2-3-2008:  Vitamin D & Cardiovascular Health; Vitamin D & Breast Cancer; Green Tea & Colorectal Cancer

1-27-2008:  Colorectal Cancer, Esophageal Cancer & Pancreatic Cancer: Update from the 2008 American Society of Clinical Oncology’s Gastrointestinal Cancers Symposium

1-20-2008:  Testosterone Levels & Risk of Fractures in Elderly Men; Air Pollution & DNA Damage in Sperm; Statins & Trauma Survival in the Elderly

1-12-2008:  Statins, Diabetes & Stroke and Obesity; GERD & Esophageal Cancer

1-7-2008:  Testosterone Supplements in Elderly Men; Colorectal Cancer– Reasons for Poor Compliance with Screening Recommendations

12-31-2007:  Minority Women, Hormone Replacement Therapy & Breast Cancer; Does Health Insurance Improve Health?

12-23-2007: Is Coffee Safe After a Heart Attack?; Impact of Divorce on the Environment; Hypertension & the Risk of Dementia; Emotional Vitality & the Risk of Heart Disease

12-16-2007:  Honey vs. Dextromethorphan vs. No Treatment for Kids with Night-Time Cough, Acupuncture & Hot Flashes in Women with Breast Cancer, Physical Activity & the Risk of Death, Mediterranean Diet & Mortality

12-11-2007:  Bias in Medical Research; Carbon Nanotubes & Radiofrequency: A New Weapon Against Cancer?; Childhood Obesity & Risk of Adult Heart Disease

12-2-2007:  Obesity & Risk of Cancer; Testosterone Level & Risk of Death; Drug Company Funding of Research & Results; Smoking & the Risk of Colon & Rectal Cancer 

Dr. Wascher’s Home Page

LEAVE A REPLY

Please enter your comment!
Please enter your name here

This site uses Akismet to reduce spam. Learn how your comment data is processed.