Are folate supplements bad for prostate health?

Folate Supplements and Prostate Health: Evidence and Recommendations

Folate supplements may be harmful for prostate health, as evidence suggests they can increase the risk of prostate cancer. 1

Evidence on Folate and Prostate Cancer Risk

Increased Risk with Supplementation

• A large multicenter U.S. trial found that folic acid supplementation was associated with increased numbers of non-colorectal cancers, particularly prostate cancer 1
• The U.S. Preventive Services Task Force (USPSTF) reported that in one trial studying folic acid, there was an increased incidence of cancer attributed to an excess number of deaths from prostate cancer in the intervention group 1
• A dose-response meta-analysis found that while dietary folate intake had little effect on prostate cancer risk, increased serum folate levels were associated with a 21% higher risk of prostate cancer (RR = 1.21; 95% CI = 1.05-1.39) 2

Conflicting Evidence

• Some studies suggest a protective effect of dietary folate (not supplements):
  • An Italian case-control study found that dietary folate intake was associated with reduced risk of prostate cancer (OR = 0.66; 95% CI, 0.51-0.85) 3
  • Another case-control study showed dietary folate was inversely associated with risk of high-grade prostate cancer 4

Important Distinction

• There appears to be a dual role of folate in prostate carcinogenesis 5:
  • Dietary folate from food sources may be protective or neutral
  • Synthetic folic acid from supplements may increase prostate cancer risk

Clinical Implications and Recommendations

For Men with Prostate Cancer

• For men with prostate cancer, especially those on active surveillance, reducing folic acid intake may be beneficial 6
• A pilot study demonstrated the feasibility of reducing dietary folic acid intake in men with low-grade prostate cancer, which successfully lowered serum and red blood cell folate without harmful effects 6

For Men Without Prostate Cancer

• The NCCN Guidelines for Colorectal Cancer Screening (2024) include a cautionary statement that although folate has been linked to decreased risk of conventional adenomas, some evidence suggests it may increase the risk of serrated polyps 1
• Men should aim to get folate through natural dietary sources rather than supplements when possible

Risk Factors and Considerations

High-Risk Groups

• Men with existing prostate cancer or elevated PSA levels should be particularly cautious about folate supplementation
• Men with a family history of prostate cancer should discuss folate supplementation with their healthcare provider

Dosage Considerations

• Higher doses of folic acid supplementation appear to carry greater risk
• The standard recommended daily intake of folate for adults is 400mcg, but even this amount may be concerning when obtained through supplements rather than diet for men concerned about prostate health

Practical Advice

• Focus on obtaining folate through natural food sources (leafy greens, legumes, fruits) rather than supplements
• If supplements are necessary for other health reasons, discuss the potential risks with your healthcare provider, especially if you have prostate concerns
• Consider regular PSA monitoring if you must take folate supplements
• Be aware that many multivitamins contain folic acid, so check labels carefully

The evidence suggests a cautious approach to folate supplementation for men concerned about prostate health, with preference given to obtaining folate through a balanced diet rather than through synthetic supplements.