British Journal of Nutrition

Full Papers

Human and Clinical Nutrition

Effects of EPA, γ-linolenic acid or coenzyme Q10 on serum prostate-specific antigen levels: a randomised, double-blind trial

Mohammad Reza Safarinejada1 c1, Nayyer Shafieia1 and Shiva Safarinejada1 

a1 Clinical Center for Urological Disease Diagnosis and Private Clinic Specialized in Urological and Andrological Genetics, PO Box 19395-1849, Tehran, Iran


The main objective of the present study was to determine the potential of n-3 and n-6 fatty acids or coenzyme Q10 (CoQ10) to alter serum prostate-specific antigen (PSA) levels in normal healthy men. A total of 504 healthy men with serum PSA level ≤ 2·5 ng/ml were recruited into the study. Serum PSA values were not segregated by decade of age. Participants were randomly assigned to a daily dietary supplement containing n-3 fatty acids (1·12 g of EPA and 0·72 g of DHA per capsule) (group 1, n 126), n-6 fatty acid (600 mg γ-linolenic acid (GLA) each capsule) (group 2, n 126), CoQ10 (100 mg per capsule) (group 3, n 126) or a similar regimen of placebo (group 4, n 126) for 12 weeks. Study medication was administered as two capsules to be taken twice daily. Serum levels of PSA, EPA, DHA, GLA, lipid profile and reproductive hormones were also measured. EPA treatment significantly reduced serum PSA level by 30·0 (95 % CI 25, 36) % (P= 0·004) from baseline. In contrast, GLA therapy significantly increased serum PSA concentration by 15·0 (95 % CI 11, 20) % (P= 0·02). CoQ10 therapy also significantly reduced serum PSA level by 33·0 (95 % CI 27, 40) % (P= 0·002). In multivariable analysis, serum values of PSA were strongly correlated with duration of EPA (r − 0·62; 95 % CI − 0·42, − 0·77; P= 0·003), n-6 (r 0·42; 95 % CI 0·31, 0·58; P= 0·02) and CoQ10 use (r − 0·77; 95 % CI − 0·56, − 0·87; P= 0·001). There were also significant correlations between serum values of DHA, EPA, GLA and CoQ10 and serum PSA levels. The present study demonstrates that dietary supplements containing EPA, GLA or CoQ10 may significantly affect serum PSA levels.

(Received May 21 2012)

(Revised September 20 2012)

(Accepted September 20 2012)

(Online publication November 30 2012)

Key Words:

  • Prostate-specific antigen;
  • Measurement;
  • n-3 Fatty acids;
  • n-6 Fatty acids;
  • Coenzyme Q10 ;
  • Prostate cancer


c1 Corresponding author: M. R. Safarinejad, fax +98 21 22456845, email


  The authors dedicate this paper to the memory of Shiva Safarinejad.

  Abbreviations: CoQ10, coenzyme Q10; DHT, dihydrotestosterone; GLA, γ-linolenic acid; LH, luteinising hormone; PCa, prostate cancer; PSA, prostate-specific antigen; SHBG, sex hormone binding globulin