OligozoospermiaNCT01954498
Effect of Walnuts on Sperm Parameters and Male Fertility
A study testing Walnuts and OTC multivitamin in people with Oligozoospermia and Asthenozoospermia, run by University of California, Los Angeles at 2 sites in United States.
Trial 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. Read more about this study
- Who is it for?
- Ages 21 years and older, men only
- Conditions the study is for
- Oligozoospermia, Asthenozoospermia, Teratozoospermia
- What is being tested?
- Walnuts and OTC multivitamin
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 80 participants
- Where
- 2 sitesUnited States
- Study dates
- May 2014to Mar 2020
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 21 years and older
- Men only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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
Who cannot join
- Allergy to walnuts or tree nuts
- Food allergy
- Known genetic cause of infertility
- Known anatomical cause of infertility
- History of seizure disorder
Trial locations and contacts
2 sites in 1 country.
United States2 sites
Male Reproductive Medicine and Microsurgery Clinic, Cedars-Sinai Medical Center
Los Angeles, California, 90048
University of California Los Angeles
Los Angeles, California, 90095
About this study
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.
Read the 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.
- Conditions
- Oligozoospermia, Asthenozoospermia, Teratozoospermia, Fertility
- Being tested
- Walnuts, OTC multivitamin
- Keywords
- Randomized controlled trial, Spermatozoa, Sperm, Male Infertility, Walnuts, Nutrition, Male Reproduction
- Medical subject headings
- Oligospermia, Asthenozoospermia, Teratozoospermia, Infertility, Male
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
WalnutsDietary supplement
OTC multivitaminDietary supplement
| Study group | Role | What they receive |
|---|---|---|
| Walnuts | Experimental | 2 ounces whole-shelled walnuts per day for 12 weeks Receives: Dietary Supplement: Walnuts |
| OTC (over-the-counter) multivitamin | Active comparator | OTC multivitamin tablet 2 per day for 12 weeks Receives: Dietary Supplement: OTC multivitamin |
What is being measured
The primary outcome is the main question the study is designed to answer.
Sperm count
Change from baseline to three months in sperm count
Measured: 12 weeks
Sperm motility
Change from baseline to 12 weeks in sperm motility
Measured: 12 weeks
Sperm morphology
Change from baseline to 12 weeks in sperm morphology
Measured: 12 weeks
Secondary outcomes (4)
Fertility
Fertilization of ova through natural conception or assisted reproductive technology
Measured: 12 months
Blood fatty acid and nutrient profile
Change from baseline to 12 weeks in blood fatty acid profile and nutrients
Measured: 12 weeks
Sperm aneuploidy
Change from baseline to 12 weeks in sperm aneuploidy
Measured: 12 weeks
Sperm DNA strand breakage
Change from baseline to 12 weeks in sperm DNA integrity
Measured: 12 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Oct 2013 (estimated)
- Study startMay 2014
- Primary completionMar 2020
- Study completionMar 2020
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for OligozoospermiaStudies of the same condition, open and under way.
- More trials run by University of California, Los AngelesThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 80 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of California, Los Angeles
- Sponsor type
- University, hospital or other
- Collaborators
- Cedars-Sinai Medical Center
- Responsible party
- Sponsor
- Investigators
- Howard H Kim, MD, Principal investigator, Cedars-Sinai Medical Center, Los Angeles, CAWendie A Robbins, RN, PhD, Principal investigator, University of California, Los Angeles
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01954498
- Sponsor's protocol ID
- 20130929
- Status last verified
- Nov 2020
- First submitted
- 20 Sep 2013
- Last updated
- 13 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
Publications
Robbins WA, Xun L, FitzGerald LZ, Esguerra S, Henning SM, Carpenter CL. Walnuts improve semen quality in men consuming a Western-style diet: randomized control dietary intervention trial. Biol Reprod. 2012 Oct 25;87(4):101. doi: 10.1095/biolreprod.112.101634. Print 2012 Oct.
PubMed 22895856
Study at a glance
From the registry record, last updated by the sponsor on 13 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Walnuts on Sperm Parameters and Male Fertility
- ClinicalTrials.gov ID
- NCT01954498
- Acronym / sponsor ID
- 20130929
- Conditions
- Oligozoospermia, Asthenozoospermia, Teratozoospermia, Fertility
- Keywords
- Randomized controlled trial, Spermatozoa, Sperm, Male Infertility, Walnuts, Nutrition, Male Reproduction
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 80 participants (actual)
- Lead sponsor
- University of California, Los AngelesUniversity, hospital or other
- Collaborators
- Cedars-Sinai Medical Center
- Study start
- May 2014
- Primary completion
- Mar 2020 (actual)
- Study completion
- Mar 2020 (actual)
- First posted
- 1 Oct 2013 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Walnuts | Experimental | Dietary Supplement: Walnuts2 ounces whole-shelled walnuts per day for 12 weeks |
| OTC (over-the-counter) multivitamin | Active comparator | Dietary Supplement: OTC multivitaminOTC multivitamin tablet 2 per day for 12 weeks |
Who may qualify
- Ages
- 21 years and older
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- 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
Key exclusion criteria (5 listed)
- Allergy to walnuts or tree nuts
- Food allergy
- Known genetic cause of infertility
- Known anatomical cause of infertility
- History of seizure disorder
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Walnuts | Dietary supplement | Walnuts |
| OTC multivitamin | Dietary supplement | OTC (over-the-counter) multivitamin |
Primary outcome
Sperm count
Time frame: 12 weeks
Change from baseline to three months in sperm count
Sperm motility
Time frame: 12 weeks
Change from baseline to 12 weeks in sperm motility
Sperm morphology
Time frame: 12 weeks
Change from baseline to 12 weeks in sperm morphology
4 secondary outcomes
Fertility
Time frame: 12 months
Blood fatty acid and nutrient profile
Time frame: 12 weeks
Sperm aneuploidy
Time frame: 12 weeks
Sperm DNA strand breakage
Time frame: 12 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Mar 2026.
- Background: PubMed 22895856Robbins WA, Xun L, FitzGerald LZ, Esguerra S, Henning SM, Carpenter CL. Walnuts improve semen quality in men consuming a Western-style diet: randomized control dietary intervention trial. Biol Reprod. 2012 Oct 25;87(4):101. doi: 10.1095/biolreprod.112.101634. Print 2012 Oct.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Howard H Kim, MD principal investigator
Cedars-Sinai Medical Center, Los Angeles, CA
Wendie A Robbins, RN, PhD principal investigator
University of California, Los Angeles
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Walnuts and OTC multivitamin in people with Oligozoospermia and Asthenozoospermia, run by University of California, Los Angeles at 2 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 13 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Sperm count (time frame: 12 weeks). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT01954498, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Mar 2026.