Influence of pistachios on performance and exercise-induced inflammation, oxidative stress, immune dysfunction, and metabolite shifts in cyclists: a randomized, crossover trial

Abstract

Objectives: Pistachio nut ingestion (3 oz./d, two weeks) was tested for effects on exercise performance and 21-h post-exercise recovery from inflammation, oxidative stress, immune dysfunction, and metabolite shifts.

Methods: Using a randomized, crossover approach, cyclists (N = 19) engaged in two 75-km time trials after 2-weeks pistachio or no pistachio supplementation, with a 2-week washout period. Subjects came to the lab in an overnight fasted state, and ingested water only or 3 oz. pistachios with water before and during exercise. Blood samples were collected 45 min pre-exercise, and immediately post-, 1.5-h post-, and 21-h post-exercise, and analyzed for plasma cytokines, C-reactive protein (CRP), F2-isoprostanes (F2-IsoP), granulocyte phagocytosis (GPHAG) and oxidative burst activity (GOBA), and shifts in metabolites.

Results: Performance time for the 75-km time trial was 4.8% slower under pistachio conditions (2.84 ± 0.11 and 2.71 ± 0.07 h, respectively, P = 0.034). Significant time effects were shown for plasma cytokines, CRP, F2-IsoP, GPHAG, and GOBA, with few group differences. Metabolomics analysis revealed 423 detectable compounds of known identity, with significant interaction effects for 19 metabolites, especially raffinose, (12Z)-9,10-Dihydroxyoctadec-12-enoate (9,10-DiHOME), and sucrose. Dietary intake of raffinose was 2.19 ± 0.15 and 0.35 ± 0.08 mg/d during the pistachio and no pistachio periods, and metabolomics revealed that colon raffinose and sucrose translocated to the circulation during exercise due to increased gut permeability. The post-exercise increase in plasma raffinose correlated significantly with 9,10-DiHOME and other oxidative stress metabolites.

Conclusions: In summary, 2-weeks pistachio nut ingestion was associated with reduced 75-km cycling time trial performance and increased post-exercise plasma levels of raffinose, sucrose, and metabolites related to leukotoxic effects and oxidative stress.

Trial registration: ClinicalTrials.gov NCT01821820.

Conflict of interest statement

Competing Interests: The authors confirm that funding through the American Pistachio Growers did not alter the authors' adherence to PLOS ONE policies on sharing data and materials.

Figures

Figure 1. Subject flow diagram.

Figure 2. Performance time for the 75-km trial under pistachio compared to water-only conditions (mean±SE).

*  =  Q-value 2-way ANOVA contrasts

Figure 3. Plasma raffinose in pistachio and water conditions (interaction effect, Q

*  =  Q-value 2-way ANOVA contrasts

Figure 4. Plasma sucrose in pistachio and water conditions (interaction effect, Q

*  =  Q-value 2-way ANOVA contrasts

Figure 5. Plasma 9,10 DiHOME in pistachio and water conditions (interaction effect, Q

*  =  Q-value 2-way ANOVA contrasts