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Effect of Walnuts on Sperm Parameters and Male Fertility

Effect of Walnuts on Sperm Parameters and Male Fertility

Status
Completed
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01954498
Enrollment
80
Registered
2013-10-01
Start date
2014-05-01
Completion date
2020-03-01
Last updated
2026-03-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Oligozoospermia, Asthenozoospermia, Teratozoospermia, Fertility

Keywords

Randomized controlled trial, Spermatozoa, Sperm, Male Infertility, Walnuts, Nutrition, Male Reproduction

Brief summary

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.

Detailed description

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.

Interventions

DIETARY_SUPPLEMENTWalnuts
DIETARY_SUPPLEMENTOTC multivitamin

Sponsors

University of California, Los Angeles
Lead SponsorOTHER
Cedars-Sinai Medical Center
CollaboratorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)

Eligibility

Sex/Gender
MALE
Age
21 Years to No maximum
Healthy volunteers
No

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

Design outcomes

Primary

MeasureTime frameDescription
Sperm count12 weeksChange from baseline to three months in sperm count
Sperm motility12 weeksChange from baseline to 12 weeks in sperm motility
Sperm morphology12 weeksChange from baseline to 12 weeks in sperm morphology

Secondary

MeasureTime frameDescription
Fertility12 monthsFertilization of ova through natural conception or assisted reproductive technology
Blood fatty acid and nutrient profile12 weeksChange from baseline to 12 weeks in blood fatty acid profile and nutrients
Sperm aneuploidy12 weeksChange from baseline to 12 weeks in sperm aneuploidy
Sperm DNA strand breakage12 weeksChange from baseline to 12 weeks in sperm DNA integrity

Countries

United States

Contacts

PRINCIPAL_INVESTIGATORHoward H Kim, MD

Cedars-Sinai Medical Center, Los Angeles, CA

PRINCIPAL_INVESTIGATORWendie A Robbins, RN, PhD

University of California, Los Angeles

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 14, 2026