Curcumin supplementation and exercise-induced muscle damage
By Krutika Nanavati, PhD Candidate
Curcumin is a natural polyphenol extracted from turmeric. Approximately 3.14% of turmeric is composed of three curcuminoid compounds: curcumin (diferuloylmethane), demethoxycurcumin, and bisdemethoxycurcumin. A limitation of the oral ingestion of curcumin is its poor bioavailability, which is mainly due to poor absorption, rapid metabolism, and rapid elimination. Thus, researchers have developed formulations using curcumin nanoparticles, phytosomes, micelles, and phospholipid complexes that have demonstrated an improved rate of absorption, antioxidant, and anti-inflammation properties. The commercially available supplements are typically composed of 77% diferuloylmethane, 17% demethoxycurcumin, and 6% bisdemethoxycurcumin.
In recent years, extensive research has been conducted on curcumin’s antioxidant and anti-inflammatory properties and its effects on metabolic syndrome, cancer, arthritis, and other chronic inflammatory conditions—as well as its role in reducing exercise-induced muscle damage (EIMD).
EIMD refers to damage in disrupted muscle structure, elevated levels of inflammatory cytokines, swelling of the affected area, and reduced range of motion and capacity to produce muscular force. Resistance training, high-intensity interval training, downhill running, and other similar high-load activities can lead to EIMD.
Studies have concluded that curcumin can reduce muscle soreness, improve muscle performance, and curb the typical post-exercise increase in creatine kinase (CK) level. Curcumin also helps release inflammatory and oxidative markers.
Presently, there are various curcumin supplements available on the market with varying amounts of curcuminoid content and different formulations that impact their bioavailability. Despite this, an optimal dose has yet to be established for reducing post exercise inflammation. As it stands, the effects of curcumin on athletes with EIMD has been studied using varying formulations, times of consumption and different exercise protocols. These studies have shown conclusive results on various aspects of EIMD as follows:
Muscle soreness
Post-exercise muscle soreness typically results in reduced muscle strength and function for several days. Redness and swelling are common at the site of damage. Curcumin doses of 180-2,500 mg/day during the 24 hours before and/or after exercise have been shown to reduce muscle soreness (Nicol, Rowlands, Fazakerly, & Kellett, 2015; Tanabe, Chino, Sagayama, et al., 2019). This has been attributed to a downregulated expression of the COX-2 enzyme, which influences a chemical cascade resulting in redness, swelling, and muscle pain.
Muscle performance
Curcumin has been shown to block the signalling pathway responsible for the secretion of inflammatory cytokines following high mechanical stress of muscles and joints. The reduction in inflammatory cytokines decreases swelling and improves muscle performance assessed via maximum voluntary contraction (MVC) force and joint range of motion (ROM).
According to the study by Tanabe et al., 90 mg curcumin twice a day (breakfast and dinner) for seven days after eccentric exercise reported less reduction in both MVC force and ROM 3‐7 days after exercise in untrained males. This suggests curcumin supplementation could be beneficial for maintaining muscle performance.
Creatine Kinase
Creatine Kinase (CK) is a marker of EIMD. Blood concentrations significantly rise following damage-inducing exercise due to myofibril damage. Curcumin supplementation has been shown to lower plasma CK concentration indirectly in multiple ways, including improved membrane integrity and vascular permeability which limits the movement of CK from muscle into blood. The antioxidant properties of curcumin can suppress muscle damaging reactive oxygen species (ROS) generated during muscle contractions. This decreases the amount of CK released into the blood. These observations have been made following a curcumin intake of 150-1,500 mg/day before and/or after exercise (McAllister et al., 2020; Tanabe et al., 2015).
Inflammatory markers
Curcumin exerts an anti-inflammatory effect by reducing pro-inflammatory signaling cascades, including NF-κB, JAK/STAT proteins, and MAPK signalling, which occur following EIMD. A dose of 180-2,000 mg/day before exercise has been shown to reduce in part these inflammatory signalling pathways following exercise in both trained and untrained individuals (Drobnic et al., 2014; Tanabe, Chino, Ohnishi, et al., 2019).
Oxidative markers
Exercise can induce oxidative stress by contributing to production of excessive amounts of ROS, which can damage DNA, proteins, and lipids and affect exercise performance. Curcumin, via its suppression of inflammatory signal pathways, can potentially lead to elevated antioxidant responses by activating nuclear factor erythroid 2–related factor (NRF2). This regulates the synthesis of antioxidant proteins that protect against oxidative damage triggered by injury and inflammation.
Thus, activation of NRF2 can improve the total antioxidant capacity of the body and reduce the harmful effects of ROS. Additionally, due to its chemical structure, curcumin itself has the potential to act as a ROS scavenger reducing the activity of lipid hydroperoxides. Based on available evidence, doses of 90-180 mg of curcumin 2 hours before or immediately after exercise may improve the body’s antioxidant capacity (Takahashi et al., 2014).
Summary
Factors which likely contribute to the varied study findings include training status of participants, the exercise protocols utilised, length of the study, timing of curcumin ingestion, and the formulation of the curcumin supplement (including the factors that affect the rate of absorption).
Overall, curcumin supplementation is effective in reducing EIMD when consumed by untrained individuals. Supplementation immediately after exercise and/or within at least 24 h before and/or after exercise is typically recommended. A suggested supplementation dose of 150-2,500 mg/day of curcumin in the form of commercially available capsules may effectively improve EIMD in individuals.
Author
AuthorKrutika Nanavati, MSc, PhD Candidate
Krutika is an associate nutritionist specializing in sport and performance nutrition. She currently is in her second year of PhD researching the effect of curcumin-fortified whey protein beverage and strength training on physical performance in older adults at the School of Sport, Exercise, and Nutrition, Massey University, New Zealand.
References
Drobnic, F., Riera, J., Appendino, G., Togni, S., Franceschi, F., Valle, X., . . . Tur, J. (2014). Reduction of delayed onset muscle soreness by a novel curcumin delivery system (Meriva®): a randomised, placebo-controlled trial. Journal of the International Society of Sports Nutrition, 11(1), 31. doi:https://doi.org/10.1186/1550-2783-11-31
McAllister, M. J., Basham, S. A., Waldman, H. S., Smith, J. W., Butawan, M. B., & Bloomer, R. J. (2020). Effects of Curcumin on the Oxidative Stress Response to a Dual Stress Challenge in Trained Men. Journal of Dietary Supplements, 17(3), 261-272. doi:https://doi.org/10.1080/19390211.2018.1515142
Nicol, L. M., Rowlands, D. S., Fazakerly, R., & Kellett, J. (2015). Curcumin supplementation likely attenuates delayed onset muscle soreness (DOMS). Eur J Appl Physiol, 115(8), 1769-1777. doi:https://doi.org/10.1007/s00421-015-3152-6
Takahashi, M., Suzuki, K., Kim, H. K., Otsuka, Y., Imaizumi, A., Miyashita, M., & Sakamoto, S. (2014). Effects of curcumin supplementation on exercise-induced oxidative stress in humans. Int J Sports Med, 35(6), 469-475. doi:https://doi.org/10.1055/s-0033-1357185
Tanabe, Y., Chino, K., Ohnishi, T., Ozawa, H., Sagayama, H., Maeda, S., & Takahashi, H. (2019). Effects of oral curcumin ingested before or after eccentric exercise on markers of muscle damage and inflammation. Scand J Med Sci Sports, 29(4), 524-534. doi:https://doi.org/10.1111/sms.13373
Tanabe, Y., Chino, K., Sagayama, H., Lee, H. J., Ozawa, H., Maeda, S., & Takahashi, H. (2019). Effective Timing of Curcumin Ingestion to Attenuate Eccentric Exercise-Induced Muscle Soreness in Men. J Nutr Sci Vitaminol (Tokyo), 65(1), 82-89. doi:https://doi.org/10.3177/jnsv.65.82
Tanabe, Y., Maeda, S., Akazawa, N., Zempo-Miyaki, A., Choi, Y., Ra, S. G., . . . Nosaka, K. (2015). Attenuation of indirect markers of eccentric exercise-induced muscle damage by curcumin. Eur J Appl Physiol, 115(9), 1949-1957. doi:https://doi.org/10.1007/s00421-015-3170-4
