Dietary Factors
Because a Western lifestyle is associated with prostate cancer, dietary factors have been intensively studied. Results have been inconsistent and inconclusive, however.
Fats. Some studies have found an association between high fat intake and prostate cancer. In particular, high consumption of red meat and high-fat dairy products has been linked to increased risk for prostate cancer. In contrast, the omega-3 fats in fish may be protective.
Vegetables and Fruits. A diet rich in vegetables, fruits, and legumes appears to protect against prostate cancer. However, it is not clear whether this is due to the nutrients contained in these foods, or the fact that these foods are low in fat. No specific vegetable or fruit has been proven to decrease risk. Lycopene, which is found in tomatoes, has been a target of research interest, but the evidence for its protective benefit is still inconclusive.
Vitamins and Minerals. Major clinical studies have found that vitamin and mineral supplements (vitamin E, vitamin C, vitamin D, and selenium) do not prevent prostate cancer. Nutritious foods that are part of a healthy diet are the best sources for vitamins and minerals. A high intake of calcium has been linked to an increased risk of prostate cancer in some studies.
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Click the icon to see an image of the sources of vitamin D. |
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Click the icon to see an image of the sources of vitamin E. |
5-ARI Drugs for Prostate Cancer Prevention
Finasteride (Proscar, generic) and dutasteride (Avodart) are drugs used to treat benign prostatic hyperplasia (BPH). They block an enzyme that converts testosterone to dehydroepiandrosterone (DHEA), the form of the male hormone that stimulates the prostate. These medications belong to a drug class called 5-alpha-reductase (5-ARI) inhibitors.
In 2009, the American Society of Clinical Oncology (ASCO) and the American Urological Association (AUA) issued a joint guideline recommending that doctors discuss the pros and cons of the use of 5-ARIs for prostate cancer prevention with men who:
- Have a PSA score of 3.0 or below
- Are being screened yearly for prostate cancer
- Do not yet show signs of prostate cancer
ASCO/AUA also recommended that patients who already take finasteride or dutasteride for controlling urinary symptoms of BPH should talk with their doctors about continuing to take the drug for prostate cancer prevention.
The guideline is the first to recommend drug therapy for preventing prostate cancer, particularly for men who are at increased risk for this disease. However, some researchers believe that 5-ARI drugs do not prevent aggressive, life-threatening prostate cancer but merely temporarily shrink low-grade tumors that probably would never become deadly. Many doctors disagree with the ASCO/AUA guideline. Some doctors feel because 5-ARI drugs can reduce PSA levels, they may give men a false sense of security and delay prostate cancer diagnosis.
Finasteride and dutasteride may cause reduced sexual drive and problems with erection, particularly during the first 1 - 2 years of use. It is not yet known what the long-term effects of 5-ARIs are if they are taken for longer than 7 years.
Review Date: 07/26/2010
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine,
Harvard Medical School; Physician, Massachusetts General Hospital.
Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M.,
Inc.
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)
