Effect of Pistachios on Muscle Recovery

Pistachios as a Recovery Food Following Rigorous Exercise in Trained Athletes

Pistachios are an understudied and often unappreciated functional food. While nuts in general have received somewhat more attention for their nutritional properties from researchers, practitioners and the media, pistachios often seem to be overlooked. Meanwhile, pistachios appear to possess characteristics that suggest that they are likely to impart benefits that are equal to and perhaps above and beyond those of average nuts. We intend to explore the potential impacts of pistachios on recovery from rigorous exercise in well-trained athletes. We hypothesize that feeding 1.5 oz of pistachios will improve exercise recovery as determined by a reduction in delayed onset muscle soreness and suppression of markers of muscle damage, inflammation and oxidative stress in comparison to water and that the benefits will be greater with consumption of 3.0 oz of pistachios.

Study Overview

• Status: Completed
• Conditions: Muscle Soreness
• Intervention / Treatment: Dietary supplement: Water; Dietary supplement: 1.5 oz Pistachios; Dietary supplement: 3.0 oz Pistachios

Detailed Description

Specific objectives are to determine the dose response to ingestion of pistachios for promotion of recovery from vigorous exercise. To accomplish this, investigators will examined whether regular consumption of pistachios followed by pistachio feeding at two different doses (1.5 and 3.0 oz) during the recovery period following eccentrically biased exercise (downhill running) promotes enhanced recovery as measured by muscle soreness, markers of muscle damage, and status for inflammation and oxidative stress in comparison to a control feeding of water in endurance-trained runners (18-35 years of age).

Study Design

A cross-over design performed in random order will be utilized in which participants will complete 3 trials separated by at least 3-4 weeks. At each testing site, 28 well-trained, competitive male athletes will be recruited. Participants will be required to participate in at least 5 hours of vigorous exercise per week and to actively compete in sport. Exclusion criteria include smoking, medications known to impact inflammation, musculoskeletal limitations and use of supplements known to impact antioxidant or inflammatory status within 1 month of participation.

Approach/Methods

Participants will consume water only, water plus 1.5 oz of pistachios, or water plus 3.0 oz of pistachios daily for 2 weeks during 3 separate trials in a randomized, cross-over fashion. Subjects will then report to the laboratory following an overnight fast and after abstaining from strenuous exercise for 2 days. Fasting blood samples will be collected and participants will complete a 40-min downhill run at -10% grade at 65-70% of a predetermined VO2max. A recovery serving of water or water along with one of the doses of pistachios will be provided. Antecubital blood samples will be collected before the bout of exercise and 24, 48, and 72 hours afterward. Muscle soreness will be assessed at each timepoint as well. Vertical jump will be assessed prior to the exercise bout and at each recovery timepoint. Daily consumption of the pistachios will continue during the 72-hour recovery period.

All participants will receive individualized diet counseling by investigators on a biweekly basis. An initial 3-day food record will be analyzed using dietary software to serve as a starting point for which the diet counseling will be based. Each participant will be provided with an individualized plan outlining their required macronutrient and micronutrient intakes (including antioxidants) in grams corresponding to their habitual diet as determined by the 3-day diet diary. Once per week, participants will provide a 3-day food record to track compliance with the nutrition protocol. All participants will be provided with feedback in their next biweekly private counseling session. To ensure that the results were due, as much as possible, to the differing dietary intervention (pistachio ingestion), participants will be instructed not to take any vitamin or mineral supplements during the study.

Data will be analyzed using a repeated measures ANOVA followed by paired T-tests as post-hoc tests using SPSS. Statistical significance will accepted at P<0.05.

• Study Type: Interventional
• Enrollment (Actual): 28
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • San Diego, California, United States, 92182-7251
      • San Diego State University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 35 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

• 28 well-trained
• Competitive male athletes
• Must participate in at least 5 hours of vigorous exercise per week
• Must actively compete in sport.

Exclusion Criteria:

• Smoking
• Medications known to impact inflammation
• Medications known to impact musculoskeletal limitations
• Use of supplements known to impact antioxidant or inflammatory status within 1 month of participation

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Water Arm; Participants will consume water only as the intervention	Dietary supplement: Water; Participants will consume water only
Active Comparator: 1.5 oz Pistachios; Participants will consume water plus 1.5 oz of pistachios as the intervention	Dietary supplement: 1.5 oz Pistachios; Participants will consume water plus 1.5 oz of pistachios as the intervention
Active Comparator: 3.0 oz Pistachios; Participants will consume water plus 3.0 oz of pistachios as the intervention	Dietary supplement: 3.0 oz Pistachios; Participants will consume water plus 3.0 oz of pistachios as the intervention

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
change from baseline of serum creatine kinase at 24, 48 and 72 hours	Serum will be analyzed for concentrations of creatine kinase as marker of muscle damage	before the bout of exercise and 24, 48, and 72 hours afterward

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from baseline of serum c-reactive protein at two weeks	For change in inflammatory response	Baseline and after two weeks of test food consumption
Change from baseline of body weight at two weeks		Baseline and after two weeks of test food consumption

Collaborators and Investigators

• Sponsor: San Diego State University

Publications and helpful links

General Publications

• Rayo VU, Thayer I, Galloway SDR, Hong MY, Hooshmand S, Liu C, North E, Okamoto L, O'Neal T, Philpott J, Witard OC, Kern M. Influence of pistachios on force production, subjective ratings of pain, and oxidative stress following exercise-induced muscle damage in moderately trained athletes: A randomized, crossover trial. Metabol Open. 2022 Oct 21;16:100215. doi: 10.1016/j.metop.2022.100215. eCollection 2022 Dec.

Study record dates

Study Major Dates

• Study Start (Actual): February 5, 2019
• Primary Completion (Actual): December 15, 2021
• Study Completion (Actual): December 15, 2021

Study Registration Dates

• First Submitted: October 1, 2018
• First Submitted That Met QC Criteria: October 3, 2018
• First Posted (Actual): October 5, 2018

Study Record Updates

• Last Update Posted (Actual): May 5, 2022
• Last Update Submitted That Met QC Criteria: May 3, 2022
• Last Verified: May 1, 2022

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nervous System Diseases; Pain; Neurologic Manifestations; Musculoskeletal Diseases; Muscular Diseases; Neuromuscular Diseases; Musculoskeletal Pain; Myalgia
• Other Study ID Numbers: S00022068

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Undecided

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No