Omega-3 Polyunsaturated Fatty Acid Supplementation for Reducing Muscle Soreness after Eccentric Exercise: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Impaired skeletal muscle regeneration in diabetes: From cellular and molecular mechanisms to novel treatments

Diabetes represents a major public health concern with a considerable impact on human life and healthcare expenditures. It is now well established that diabetes is characterized by a severe skeletal muscle pathology that limits functional capacity and quality of life. Increasing evidence indicates that diabetes is also one of the most prevalent disorders characterized by impaired skeletal muscle regeneration, yet underlying mechanisms and therapeutic treatments remain poorly established. In this review, we describe the cellular and molecular alterations currently known to occur during skeletal muscle regeneration in people with diabetes and animal models of diabetes, including its associated comorbidities, e.g., obesity, hyperinsulinemia, and insulin resistance. We describe the role of myogenic and non-myogenic cell types on muscle regeneration in conditions with or without diabetes. Therapies for skeletal muscle regeneration and gaps in our knowledge are also discussed, while proposing future directions for the field.

A randomized, double-blind, placebo-controlled, repeated-dose pilot study of the safety, tolerability, and preliminary effects of a cannabidiol (CBD)- and cannabigerol (CBG)-based beverage powder to support recovery from delayed onset muscle soreness (DOMS)

BACKGROUND

Cannabinoid-containing products are marketed to athletes as promoting recovery, in spite of a lack of data on their safety and effects. This randomized, double-blind, placebo-controlled, repeated-dose pilot study tested the safety, tolerability, and preliminary effects on recovery of a formulation containing cannabidiol (CBD; 35 mg), cannabigerol (CBG; 50 mg), beta caryophyllene (BCP; 25 mg), branched-chain amino acids (BCAAs; 3.8 g), and magnesium citrate (420 mg).

METHODS

Exercise-trained individuals (N = 40) underwent an experimental induction of delayed onset muscle soreness (DOMS) and completed follow-up visits 24-, 48-, and 72-hours post-DOMS. Participants were randomized to active or placebo formulation, and consumed the formulation twice per day for 3.5 days.

RESULTS

There was one adverse event (AE) in the active group (diarrhea) and two AEs in placebo (dry mouth; eye rash/swollen eye). There was 100% self-reported compliance with formulation consumption across the two groups. For the primary outcome of interest, the estimate of effect for ratings of average soreness/discomfort 72 hours post-DOMS between active and placebo groups was -1.33 (85% confidence interval = -2.55, -0.10), suggesting moderate evidence of a treatment difference. The estimate of effect for the outcome of ratings of interference of soreness, discomfort, or stiffness on daily activities at work or home 48 hours post-DOMS was -1.82 (95% confidence interval = -3.64, -0.01), indicating a treatment difference of potential clinical importance. There was no significant effect between active and placebo groups on objective measures of recovery, sleep quality, or mood disturbance.

CONCLUSIONS

The tested formulation reduced interference of DOMS on daily activities, demonstrating its improvement on a functional aspect of recovery.

The Role of Omega-3 Polyunsaturated Fatty Acids and Their Lipid Mediators on Skeletal Muscle Regeneration: A Narrative Review

Skeletal muscle is the largest tissue in the human body, comprising approximately 40% of body mass. After damage or injury, a healthy skeletal muscle is often fully regenerated; however, with aging and chronic diseases, the regeneration process is usually incomplete, resulting in the formation of fibrotic tissue, infiltration of intermuscular adipose tissue, and loss of muscle mass and strength, leading to a reduction in functional performance and quality of life. Accumulating evidence has shown that omega-3 (n-3) polyunsaturated fatty acids (PUFAs) and their lipid mediators (i.e., oxylipins and endocannabinoids) have the potential to enhance muscle regeneration by positively modulating the local and systemic inflammatory response to muscle injury. This review explores the process of muscle regeneration and how it is affected by acute and chronic inflammatory conditions, focusing on the potential role of n-3 PUFAs and their derivatives as positive modulators of skeletal muscle healing and regeneration.

Dietary Habits and Musculoskeletal Pain in Statin and Red Yeast Rice Users: A Pilot Study

(1) Background: Diet and statins are commonly used to treat high cholesterol (CHOL) levels. (2) Aim: To compare adherence to Mediterranean diet (Med-D), orthorexia nervosa (ON), and musculoskeletal pain in individuals in treatment with statins metabolized by CYP3A4, not metabolized by CYP3A4 or red yeast rice (RYR, containing monacolin K: MON-K). (3) Methods: starting from 80 individuals, after the exclusion of those with other causes of possible pain, 56 individuals were selected and divided into three groups according to the type of statin (CYP3A4, NO-CYP3A4 and MON-K). Adherence to the Med-D was evaluated with the MEDScore and a sub-score was calculated for fruit and vegetables consumption (MEDScore-FV). ON and musculoskeletal pain were assessed with the ORTO-15 and with the Nordic Musculoskeletal questionnaires, respectively. A retrospective analysis of CHOL decrease after treatment was conducted. (4) Results: CHOL levels were lower in CYP3A4 and NO-CYP3A4 after treatment (182.4 ± 6.3 and 177.0 ± 7.8 mg/dL, respectively), compared with MON-K (204.2 ± 7.1 mg/dL, p < 0.05). MON-K and CYP3A4 groups had a high prevalence of reported knee pain (33.3% and 18.8%, respectively) than NO-CYP3A4 group (0%, p < 0.05). A high percentage of individuals in MON-K take supplements and nutraceuticals (87.5%), whereas MEDScore-FV was higher in CYP3A4 (9.4 ± 0.2) compared to NO-CYP3A4 (7.6 ± 0.5, p < 0.05). (5) Conclusions: This study suggests that individuals receiving treatment with statins and RYR should be monitored from the perspective of plant foods’ consumption and nutraceutical use, to prevent musculoskeletal pain.

The effect of Omega-3 polyunsaturated fatty acid supplementation on exercise-induced muscle damage

Background

Exercise-induced muscle damage (EIMD) results in transient muscle inflammation, strength loss, muscle soreness and may cause subsequent exercise avoidance. Omega-3 (n-3) supplementation may minimise EIMD via its anti-inflammatory properties, however, its efficacy remains unclear.

Methods

Healthy males (n = 14, 25.07 ± 4.05 years) were randomised to 3 g/day n-3 supplementation (N-3, n = 7) or placebo (PLA, n = 7). Following 4 weeks supplementation, a downhill running protocol (60 min, 65% V̇O₂max, − 10% gradient) was performed. Creatine kinase (CK), interleukin (IL)-6 and tumour necrosis factor (TNF)-α, perceived muscle soreness, maximal voluntary isometric contraction (MVIC) and peak power were quantified pre, post, and 24, 48 and 72 h post-EIMD.

Results

Muscle soreness was significantly lower in N-3 vs PLA group at 24 h post-EIMD (p = 0.034). IL-6 was increased in PLA (p = 0.009) but not in N-3 (p = 0.434) following EIMD, however, no significant differences were noted between groups. Peak power was significantly suppressed in PLA relative to pre-EIMD but not in N-3 group at 24 h post-EIMD. However, no significant difference in peak power output was observed between groups. MVIC, CK and TNF-α were altered by EIMD but did not differ between groups.

Conclusion

N-3 supplementation for 4 weeks may successfully attenuate minor aspects of EIMD. Whilst not improving performance, these findings may have relevance to soreness-associated exercise avoidance.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12970-020-00405-1.