# Polyphenols improve muscle strength in two out of five clinical trials

- Published: 2026-11-07 23:05 UTC
- Section: Life & Health › Medicine
- Tags: polyphenols muscle strength, sarcopenia clinical trial, Diaz-Vallejo review, quercetin resistance training, musculoskeletal aging, dietary interventions
- URL: https://realtech.media/news/rt-2c3fb148f3106477ed231d5e_polyphenols_improve_muscle/

**A systematic review in older adults shows inconsistent evidence regarding the benefits of plant compounds for skeletal muscle, ruling out therapeutic recommendations.**

![Polyphenols improve muscle strength in two out of five clinical trials](https://realtech.media/media/2026/11/1950f12842df3a3b.webp)
*ad-hoc-news.de*

Plant polyphenols continue to yield contradictory outcomes in nutritional research targeting age-related muscle maintenance. A systematic review published in *GeroScience* by Diaz-Vallejo, Gonzalez-Correa, and Padilla identified six randomized controlled trials, of which five reported finalized results involving individuals aged 55 years and older with intervention durations ranging between 4 and 24 weeks, according to ad-hoc-news.de [1]. The evaluated compounds included quercetin, tea catechins, epicatechin extracts, cocoa flavonoids, and marine polyphenols. Significant gains in muscle strength compared to controls emerged in only two of the five evaluated studies [1].

## Clinical evidence and sarcopenia

Quercetin combined with resistance training improved grip and leg strength over exercise alone in the analyzed cohort [1]. However, changes in overall muscle mass across the reviewed studies remained inconsistent. Only two studies included participants with diagnosed sarcopenia, and neither recorded definitive strength gains from the intervention. Due to marked study heterogeneity, the authors avoided pooling the statistical estimates and concluded that current evidence remains insufficient to support targeted therapeutic recommendations [1].

Similar limitations were documented in a review by Gil-Caselles in *Nutrients*, which assessed ten independent clinical trials of olive derivatives, maslinic acid, and related compounds. Maslinic acid was associated with reduced subjective fatigue and soreness, yet consistent improvements in objective physical capacity or ergogenic performance could not be verified [1].

## Biomarkers and cellular pathways

Observational data highlight biological correlations without confirming clinical causation. A cross-sectional study in *Food & Function* evaluating 50 individuals found that urinary metabolites, including catechin sulfate and resveratrol derivatives, positively correlated with grip strength, skeletal muscle mass, and ultrasound measures of the quadriceps in women [1]. In cell culture experiments with C2C12 muscle cells, pterostilbene decreased intracellular lipid accumulation via PPAR-gamma receptor stabilization, though these findings provide no baseline for human bioavailability or dosage [1].

Exercise interventions similarly demonstrate targeted biological responses rather than uniform physical gains. McFarlin and colleagues observed that a 28-day regimen of curcuminoids and pomegranate ellagitannins reduced immune pathway suppression by an average of 25 percent and enhanced metabolic recovery pathway activation by 232 percent following a half-marathon [1]. Conversely, trials testing nitrate-rich beetroot juice in recreationally trained women and cornelian cherry in professional athletes found no statistically significant differences in repetitions to failure, blood lactate, or jump performance [1].

## Sources

1. [ad-hoc-news.de](https://www.ad-hoc-news.de/wissenschaft/muskelkraft-ab-55-polyphenole-zeigen-nur-in-zwei-von-fuenf-studien-wirkung/70476097)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-2c3fb148f3106477ed231d5e_polyphenols_improve_muscle/