Skip to main content
OpenTrials
Completed

NCT Number: NCT01954498

Effect of Walnuts on Sperm Parameters and Male Fertility

The investigators are testing the hypothesis that two ounces of whole-shelled walnuts/day added to the diet of men seeking care for infertility will beneficially affect sperm parameters and fertility. The investigators will compare the walnut intervention to the commonly suggested recommendation of adding an OTC multivitamin supplement to the diet.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Oligozoospermia Asthenozoospermia Fertility Genital Diseases Genital Diseases, Male Infertility Infertility, Male Male Urogenital Diseases Oligospermia Teratozoospermia Urogenital Diseases

Age range

21 year and older

Sex eligibility

Male

Study type

Interventional

Phase

Not applicable

Primary location

Male Reproductive Medicine and Microsurgery Clinic, Cedars-Sinai Medical Center, Los Angeles, California, United States

Loading trial locations.

About this study

Purpose: The investigators are testing the hypothesis that two ounces of whole-shelled walnuts/day added to the diet of men with oligo- astheno- or teratospermia will beneficially affect sperm parameters. The investigators found in a previous study (Robbins et al. 2012, Biology of Reproduction 87(4):101, 1-8.) that walnuts added to a Western diet improved sperm parameters in healthy, young men of unknown fertility and the most improvement occurred in participants with poor sperm parameters at baseline. The investigators now test the walnut dietary intervention in a fertility clinic population known to have poor sperm parameters. The investigators will compare the walnut intervention to the usual care suggestion of adding an OTC multivitamin supplement to the diet. Neither walnuts nor the OTC multivitamin have been tested for efficacy in this fertility clinic population previously.

Methods: A randomized, parallel two-group, dietary intervention trial with single-blind masking of outcome assessors will be conducted with up to 140 men who present for fertility work-up with semen parameters below the 25th centile for count, and 10th centile for motility and/or morphology according to the WHO 5th Edition, Laboratory Manual for the Processing and Examining of Human Semen, 2010. Repeated measures at baseline and 12 weeks include: semen analyses (primary outcome), blood fatty acid/ nutrient profiles (secondary outcomes); IPAQ physical activity questionnaire and IIEF index of erectile function (potential modifiers or confounders). Dietary intake will be assessed throughout using 24-hour ASA dietary recall x 5 and fertility assessed by questionnaire at one year post enrollment.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age 21 years or older
  • Sperm concentration < or = to 41 million per ml
  • Sperm motility < or = to 40%
  • Normal sperm morphology forms < or = to 5.5%
  • Patients of Howard H. Kim, MD seen at the Male Reproductive Medicine and Microsurgery Clinic, Cedars-Sinai Medical Center, Los Angeles, California
  • Have eaten walnuts throughout life without adverse reaction

Exclusion criteria

  • Allergy to walnuts or tree nuts
  • Food allergy
  • Known genetic cause of infertility
  • Known anatomical cause of infertility
  • History of seizure disorder

Treatment and study plan

walnuts

Dietary Supplement

OTC multivitamin

Dietary Supplement

Primary outcomes

  1. Sperm count

    Time frame: 12 weeks

    Change from baseline to three months in sperm count

  2. Sperm motility

    Time frame: 12 weeks

    Change from baseline to 12 weeks in sperm motility

  3. Sperm morphology

    Time frame: 12 weeks

    Change from baseline to 12 weeks in sperm morphology

Secondary outcomes

  1. Fertility

    Time frame: 12 months

    Fertilization of ova through natural conception or assisted reproductive technology

  2. Blood fatty acid and nutrient profile

    Time frame: 12 weeks

    Change from baseline to 12 weeks in blood fatty acid profile and nutrients

  3. Sperm aneuploidy

    Time frame: 12 weeks

    Change from baseline to 12 weeks in sperm aneuploidy

  4. Sperm DNA strand breakage

    Time frame: 12 weeks

    Change from baseline to 12 weeks in sperm DNA integrity

Other outcomes

  1. Physical Activity

    Time frame: 12 weeks

    IPAQ (International Physical Activity Questionnaire) assessment of change from baseline to 12 weeks

  2. Sexual function

    Time frame: 12 weeks

    IIEF (International Index of Erectile Function) assessment of change from baseline to 12 weeks

  3. Dietary intake

    Time frame: 12 weeks

    ASA-24 (Automated Self-administered) 24-hour dietary recalls x 5 over 12 weeks

Sponsors and collaborators

Lead sponsor

University of California, Los Angeles

Other

Collaborators

  • Cedars-Sinai Medical Center

Registry information

Important dates

Study start
2014
Primary completion
2020
Study completion
2020
First posted
Oct 1, 2013
Registry last updated
Mar 13, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.