Prostate Cancer
Malignant growth in the prostate gland, most common cancer in men.
TL;DR
Selenium and vitamin E do not prevent prostate cancer — the SELECT trial found vitamin E increased incidence. Most low-risk disease is best managed by monitoring.
Overview
Prostate cancer is unusual because much of it never needs treating. Autopsy series find microscopic prostate cancer in a large proportion of older men who died of other causes, which is why over-diagnosis is a central problem and why active surveillance has become standard for low-risk disease. The supplement story here is a cautionary one. SELECT, a trial of over 35,000 men, tested selenium and vitamin E for prevention and found vitamin E supplementation increased prostate cancer incidence by 17%, leading to early termination. Saw palmetto, widely taken for urinary symptoms, failed to beat placebo in the STEP and CAMUS trials and does not affect cancer risk either way. What does matter: PSA interpretation is complicated by supplements and drugs — finasteride roughly halves PSA, and biotin at high doses interferes with some immunoassays.
Common Symptoms
- •Weak or interrupted urinary stream
- •Frequency and nocturia
- •Difficulty starting urination
- •Blood in urine or semen
- •New persistent bone pain, particularly in the back or hips
- •Erectile dysfunction of new onset
Common Causes
- •Age over 50
- •Family history and BRCA2 mutations
- •Black African or Caribbean ancestry
- •Obesity, associated with more aggressive disease
- •Diet high in processed foods
Root Causes
Androgen-driven proliferation of prostatic epithelium with accumulated genomic alterations; strongly age-related, with inherited factors including BRCA2 conferring more aggressive disease.
How It's Diagnosed
Diagnostic Markers
- PSA with free-to-total ratio where useful
- Digital rectal examination
- Multiparametric MRI before biopsy
- Targeted or systematic biopsy with Gleason grading
- Bone scan or PSMA PET for staging in higher-risk disease
When to See a Doctor
See a doctor for blood in the urine or semen, new persistent bone pain, or urinary symptoms with weight loss. Discuss PSA testing from age 50, or 45 with a family history or Black ancestry.
Supplements Studied For This
Vitamin E
Not neutral — actively harmful in the largest trial conducted.
Selenium
A well-tested hypothesis that failed clearly.
Saw Palmetto
Popular, extensively tested, and consistently negative.
Diet & Lifestyle
Suggested Pattern
A whole-food pattern with adequate protein. No diet prevents prostate cancer, but weight management influences aggressiveness.
Eat more
- Vegetables, particularly cooked tomatoes for lycopene
- Oily fish
- Legumes and whole grains
- Adequate calcium and vitamin D on hormone therapy
Avoid
- Vitamin E supplements
- Very high dairy or calcium supplement intake, associated with modest risk increase
- Excess alcohol
- High-dose biotin before PSA testing
Supporting Research
Multivitamins in the Prevention of Cancer in Men: The Physicians' Health Study II Randomized Controlled Trial
Modified citrus pectin (MCP) increases the prostate-specific antigen doubling time in men with prostate cancer: a phase II pilot study
Modified Citrus Pectin Treatment in Non-Metastatic Biochemically Relapsed Prostate Cancer: Results of a Prospective Phase II Study
Selenium and Vitamin E Cancer Prevention Trial (SELECT): null and adverse findings
A phase II study of sulforaphane-rich broccoli sprout extracts in men with recurrent prostate cancer
Frequently Asked Questions
Who It Affects
The most common cancer in men in many high-income countries; roughly 1 in 8 men are diagnosed in their lifetime.
Incidence rises sharply after 50 and is substantially higher in men of Black African and Caribbean ancestry.
Quick Facts
- •Vitamin E increased prostate cancer incidence by 17% in the SELECT trial
- •Selenium showed no preventive benefit
- •Most urinary symptoms in older men are benign prostatic enlargement, not cancer
- •Finasteride halves PSA — results must be doubled for interpretation
Lifestyle Tips
- •Do not take vitamin E supplements for prostate prevention
- •Discuss PSA testing with your GP rather than assuming more testing is better
- •Maintain a healthy weight — obesity is linked to aggressive disease
- •Regular aerobic and resistance exercise, particularly on androgen deprivation therapy
- •Calcium and vitamin D for bone health if on hormone therapy
- •Tell your doctor about biotin supplements before any blood test
My Notes
Sign in to add personal notes
This information is for educational purposes only. Always consult a healthcare professional before starting any supplement regimen.