Clinical trial NCT01505140: Benefits of Walnuts for Male Reproductive Health
Official title: Benefits of Walnuts for Male Reproductive Health
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE2
Conditions: Infertility
Nutrition Disorders
Keywords: Andrology
Fertility
Reproduction
Diet
Nutritional Sciences
Fatty Acids
Antioxidants
Body weight changes
Lead sponsor: University of California, Los Angeles
Sponsor class: OTHER
Collaborators: name: California Walnut Commission
First posted: 2012-01-06
Enrollment: 120
Sex: MALE
Minimum age (years): 21
Maximum age (years): 35
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

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.

Eligibility criteria: Inclusion Criteria: Males

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 -

Primary outcomes:
measure: change from baseline in semen quality at 12 weeks
timeFrame: change from baseline at 12 weeks
measure: change from baseline in serum fatty acids at 12 weeks
timeFrame: change from baseline at 12 weeks
measure: change from baseline in serum selenium at 12 weeks
timeFrame: change from baseline at 12 weeks
measure: change from baseline in serum folate at 12 weeks
timeFrame: change from baseline at 12 weeks
measure: change from baseline in serum zinc at 12 weeks
timeFrame: change from baseline at 12 weeks
Secondary outcomes:
measure: change from baseline in body weight pounds at 12 weeks
timeFrame: change from baseline at 12 weeks
measure: change from baseline in nutrient intake at 12 weeks
timeFrame: change from baseline at 12 weeks
Other outcomes:
Locations:
city: Los Angeles
country: United States
facility: University of California, Los Angeles
state: California
Study officials:
affiliation: University of California, Los Angeles
name: Wendie A Robbins, RN, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: 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.