Lack of effect of walnuts on serum levels of prostate specific antigen: a brief report

J Am Coll Nutr. 2007 Aug;26(4):317-20. doi: 10.1080/07315724.2007.10719617.


Objective: To examine whether the short-term consumption of walnuts, a food rich in alpha-linolenic acid, affects levels of serum prostate-specific antigen (PSA), a marker of prostate enlargement, inflammation, and cancer.

Methods: Using data from a 12-month randomized crossover study examining the effect of walnut consumption on body composition, we examined whether increased walnut consumption (mean 35 grams daily, 12% total energy) affected serum PSA levels among 40 middle-aged men.

Results: There was no significant difference between mean PSA level at the conclusion of the 6-month walnut-supplemented diet (1.05 mug/L, 95% CI [0.81, 1.37]) and the conclusion of the 6-month control diet (1.06 mug/L, 95% CI [0.81, 1.38]) (P = 0.86) (or a mean proportional decrease in PSA of -1%).

Conclusions: Our results suggest that short-term consumption of walnuts is unlikely to affect PSA levels adversely among otherwise normal men.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Biomarkers, Tumor / blood
  • Cross-Over Studies
  • Dietary Fats, Unsaturated / administration & dosage
  • Dietary Fats, Unsaturated / pharmacology*
  • Humans
  • Juglans*
  • Male
  • Middle Aged
  • Prostate-Specific Antigen / blood*
  • Prostatic Neoplasms / blood
  • Prostatic Neoplasms / epidemiology
  • Prostatic Neoplasms / prevention & control*
  • alpha-Linolenic Acid / administration & dosage
  • alpha-Linolenic Acid / pharmacology*


  • Biomarkers, Tumor
  • Dietary Fats, Unsaturated
  • alpha-Linolenic Acid
  • Prostate-Specific Antigen