Benefits of Walnuts for Male Reproductive Health

NCT ID: NCT01505140

Last Updated: 2016-11-28

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: PHASE2
• Total Enrollment: 120 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2009-11-30
• Study Completion Date: 2010-12-31

Brief Summary

Walnuts as a whole food contain polyunsaturated fatty acids, anti-oxidants, and other nutrients essential to sperm development and function. This randomized controlled trial sought to determine if a Western style diet supplemented with walnuts would improve sperm quality as a predictor of male fertility.

Detailed Description

A vast research base on human sperm shows the following to be critical for normal sperm development and function: Polyunsaturated fatty acids provide fluidity to sperm membranes allowing sperm to swim, fuse with ova, and support key cellular functions. Antioxidants protect sperm from reactive oxygen species generated during normal physiologic processes or white blood cells that infiltrate into seminal fluid and injure membranes and fragment sperm DNA. Selenium is critical in the form of anti-oxidant selenoproteins protecting developing sperm in the testes and later selenium in the epididymis participates in cell shape for motility. Folate, in a recent study, was associated with decreased aneuploidy (abnormal number of chromosomes)in sperm. Deficiency in any of these factors - lipids, antioxidants, selenium, or folate could manifest as poor semen quality and sub-fertility.

Walnuts provide a rich dietary source of each of the critical factors discussed above. Walnuts contain beneficial lipids, antioxidants, selenium, and folate. Walnuts, as a natural whole food source, may be preferential to commercial supplements and, as a plant source of nutrients, leave a positive green footprint on the planet.

Hypothesis The investigators hypothesize that diets enriched in walnuts will improve semen quality. Semen quality is a predictive marker for male infertility and sub-fertility, thus, the overall goal is to determine if dietary intake of walnuts will benefit male reproductive health.

A randomized, controlled intervention will be used to study the effects of walnut supplementation on semen quality measures in young men (ages 21 to 35) eating Western diets. Participants will be enrolled from the West Los Angeles area (n=120). Men will be randomly assigned to consume 3 oz of walnuts per day as part of their usual diet or to continue their habitual diet but avoid nuts. Each will follow the assigned diet for three months to cover one complete cycle of spermatogenesis.

The specific aims of the study are to:

1. Establish at baseline: habitual diet; serum omega-3 to omega-6 ratio, serum selenium and folate; semen quality (sperm count, motility, morphology) and sperm DNA integrity (COMET assay); sperm aneuploidy; and semen anti-oxidant levels

2. Randomly assign men to habitual diet plus 3 oz walnuts per day or usual diet without nuts for three months monitored by six telephone 24 hour dietary recalls

3. Compare intervention and control groups at three months on blood and semen measures

4. Compare blood and semen measures within man between baseline and three months.

Conditions

Infertility; Nutrition Disorders

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: PREVENTION
• Blinding Strategy: SINGLE

Study Groups

Usual Western style diet

Participants will consume their usual Western style diet avoiding tree nuts

Group Type: NO_INTERVENTION

No interventions assigned to this group

Whole walnuts

Participants will consume usual Western style diet adding 75 gm whole walnuts per day

Group Type: EXPERIMENTAL

Whole walnuts

Intervention Type: OTHER

75 gm whole walnuts per day will be consumed with usual Western style diet

Interventions

Whole walnuts

75 gm whole walnuts per day will be consumed with usual Western style diet

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

1. Age 21 to 35 years

2. Residence is in West Los Angeles for the next three months

3. Non-smoker

4. Free from chronic diseases requiring medications

5. Free from nut allergies or nut intolerance

6. Not taking anti-oxidant supplements

Exclusion Criteria

1. Outside the age range of 21 to 35 years

2. Residence outside West Los Angeles area prohibiting two trips to the clinical research laboratory

3. Current smoker

4. Taking medications for chronic disease

5. Nut allergies or nut intolerance

6. Taking anti-oxidant supplements -

• Minimum Eligible Age: 21 Years
• Maximum Eligible Age: 35 Years
• Eligible Sex: MALE
• Accepts Healthy Volunteers: Yes

Sponsors

California Walnut Commission

OTHER

Sponsor Role: collaborator

University of California, Los Angeles

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Wendie A Robbins, RN, PhD

Role: PRINCIPAL_INVESTIGATOR

University of California, Los Angeles

Locations

University of California, Los Angeles

Los Angeles, California, United States

Countries

United States

References

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.

Reference Type: RESULT

PMID: 22895856 (View on PubMed)

Other Identifiers

445246WR77518

Identifier Type: -

Identifier Source: org_study_id