Influence of Fermented Red Clover Extract on Skeletal Muscle in Early Postmenopausal Women: A Double-Blinded Cross-Over Study

Abstract

Objective: To investigate effects of supplementation with a fermented red clover (RC) extract on signaling proteins related to muscle protein synthesis and breakdown at rest and in response to a resistance exercise bout. Methods: Ten postmenopausal women completed a double-blinded cross-over trial with two different intervention periods performed in random order: (A) RC extract twice daily for 14 days, and (B) placebo drink twice daily for 14 days. The intervention periods were separated by a two-week washout period. After each intervention period a muscle tissue sample was obtained before and three hours after a one-legged resistance exercise bout. Muscle strength was assessed before and after each intervention period. Results: Protein expression of FOXO1 and FOXO3a, two key transcription factors involved in protein degradation, were significantly lower and HSP27, a protein involved in cell protection and prevention of protein aggregation was significantly higher following RC extract compared to placebo. No significant treatment × time interaction was observed for muscle protein expression in response to exercise. However, p-mTOR, p-p70S6k and HSP90 protein content were significantly increased in response to exercise in both groups. Conclusion: This study demonstrates that RC extract supplementation downregulates molecular markers of muscle protein degradation compared to placebo in postmenopausal women.

Short-Term Supplementation With Fermented Red Clover Extract Reduces Vascular Inflammation in Early Post-menopausal Women

“…The findings from this study have unearthed novel evidence regarding the cardiovascular benefits of RC, which support the known therapeutic potential of RC in relieving menopausal symptoms (66), promoting bone health (33), and minimizing skeletal muscle breakdown (36) in post-menopausal women. Future investigations are required to elucidate the optimal dosing regime and mechanisms of action, together with reporting of potential side effects.…”

“…In recent years, advances in food science and nutraceutical biochemistry have significantly improved the bioavailability, and therefore, the therapeutic potential of red clover isoflavones via the fermentation process, which converts isoflavone glycosides to aglycones ( 33 ). Therefore, fermented red clover extract (RC) may be a safe, easily accessible, and highly efficacious therapeutic intervention to promote cardiovascular and metabolic health as well as bone health ( 33 ) and the maintenance of muscle mass and function ( 36 ) in post-menopausal women. However, to date, no study has evaluated the cardiovascular benefits in a cohort of post-menopausal women.…”

Red Clover Isoflavones Influence Estradiol Concentration, Exercise Performance, and Gut Microbiota in Female Mice

“…Endurance athletes in particular are more likely to develop gastrointestinal diseases (20). Supplementation of isoflavones through a fermented red clover extract reduces markers of protein degradation (21), increases lean body mass and muscle mass in postmenopausal women (22).…”

Efficacy and safety of phytoestrogens in the treatment of perimenopausal and postmenopausal depressive disorders: A systematic review and meta‐analysis

“…As one study found in legumes, red clover isoflavone through oestrogen receptor (ER) binding and activation of ER-dependent gene transcription, which has a relatively high binding affinity for the ERα and ERβ, isoflavones demonstrate up to ~1600 times lower affinity for ERα. 45 This may explain the significant effect of isoflavones.…”