Grape consumption's effects on fitness, muscle injury, mood, and perceived health.
Study Goal
The researchers aimed to determine whether grape consumption (containing quercetin) improved exercise performance, mood, health status, and recovery from muscle injury in humans.
Results Summary
The study found no significant effect of grape consumption on VO(2max), work capacity, mood, perceived health status, inflammation, pain, or physical-function responses to eccentric exercise-induced injury.
Population
Recreationally active young adults (n=40)
Effective Dosage
Not specified (grape drink consumed daily)
Duration
45 days
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
compounds found in the skins of grapes, including catechins, quercetin, and resveratrol, added to the diet | increase | run time to exhaustion | rodents | - | improved | #1 |
compounds found in the skins of grapes, including catechins, quercetin, and resveratrol, added to the diet | increase | fitness | rodents | - | improved | #2 |
compounds found in the skins of grapes, including catechins, quercetin, and resveratrol, added to the diet | increase | skeletal-muscle mitochondrial function | rodents | - | improved | #3 |
6 wk of daily grape consumption | no change | maximal oxygen uptake (VO(2max)) | recreationally active young adults | - | showed no significant effect | #4 |
6 wk of daily grape consumption | no change | work capacity | recreationally active young adults | - | showed no significant effect | #5 |
6 wk of daily grape consumption | no change | mood | recreationally active young adults | - | showed no significant effect | #6 |
6 wk of daily grape consumption | no change | perceived health status | recreationally active young adults | - | showed no significant effect | #7 |
6 wk of daily grape consumption | no change | inflammation | recreationally active young adults | - | showed no significant effect | #8 |
6 wk of daily grape consumption | no change | pain | recreationally active young adults | - | showed no significant effect | #9 |
6 wk of daily grape consumption | no change | arm-function responses to a mild eccentric-exercise-induced arm-muscle injury | recreationally active young adults | - | showed no significant effect | #10 |
Six weeks of supplemental grape consumption | no change | VO(2max) | recreationally active young adults | - | has no effect | #11 |
Six weeks of supplemental grape consumption | no change | work capacity | recreationally active young adults | - | has no effect | #12 |
Six weeks of supplemental grape consumption | no change | mood | recreationally active young adults | - | has no effect | #13 |
Six weeks of supplemental grape consumption | no change | perceived health status | recreationally active young adults | - | has no effect | #14 |
Six weeks of supplemental grape consumption | no change | inflammation | recreationally active young adults | - | has no effect | #15 |
Six weeks of supplemental grape consumption | no change | pain | recreationally active young adults | - | has no effect | #16 |
Six weeks of supplemental grape consumption | no change | physical-function responses to a mild injury induced by eccentric exercise | recreationally active young adults | - | has no effect | #17 |
Compounds found in the skins of grapes, including catechins, quercetin, and resveratrol, have been added to the diet of rodents and improved run time to exhaustion, fitness, and skeletal-muscle mitochondrial function. It is unknown if such effects occur in humans. The purpose of this experiment was to investigate whether 6 wk of daily grape consumption influenced maximal oxygen uptake (VO(2max)), work capacity, mood, perceived health status, inflammation, pain, and arm-function responses to a mild eccentric-exercise-induced arm-muscle injury. Forty recreationally active young adults were randomly assigned to consume a grape or placebo drink for 45 consecutive days. Before and after 42 d of supplementation, assessments were made of treadmill-running VO(2max), work capacity (treadmill performance time), mood (Profile of Mood States), and perceived health status (SF-36 Health Survey). The day after posttreatment treadmill tests were completed, 18 high-intensity eccentric actions of the nondominant elbow flexors were performed. Arm-muscle inflammation, pain, and function (isometric strength and range of motion) were measured before and on 2 consecutive days after the eccentric exercise. Mixed-model ANOVA showed no significant effect of grape consumption on any of the outcomes. Six weeks of supplemental grape consumption by recreationally active young adults has no effect on VO(2max), work capacity, mood, perceived health status, inflammation, pain, or physical-function responses to a mild injury induced by eccentric exercise.