Antioxidants have become extremely popular in recent years. They are available in supplements, foods, and even in water. But, why have antioxidants become so popular? Well, antioxidants have been shown to prevent the build-up of free radicals. Free radicals are harmful molecules that are responsible for a wide array of health problems including chronic diseases. Now, to understand the benefits of antioxidants we must understand what free radicals are and why they are harmful.
What are Free Radicals?
To maintain the normal functions of everyday life the body goes through a series of chemical reactions called metabolism. Metabolism occurs at the molecular level where every molecule carries electrons. Electrons are negatively charged particles that like to be in pairs, so they will seek out other electrons and stick together. Molecules with only one electron become a problem because they steal electrons from other molecules. This is how free radicals are made. Free radicals cause DNA to mutate, which then copies itself to another DNA, if this process is not stopped it will spiral out of control. 1,4Uncontrolled free radicals can lead to a mirror of health issues including cancer.
What are Antioxidants?
Antioxidants are molecules that act as a reducing agent by donating an electron. 4 Antioxidants combined with free radicals should eventually result in electrons being paired together. There are many different types of antioxidants, but perhaps the most common are Vitamin C and E. 1,4
Putting it all together
Now, what if I told you that free radical production is necessary to maximize muscle growth? Yes, you read that correctly. Those nasty molecules responsible for chronic diseases and health issues are needed if you want to maximize muscle mass. This is because free radicals act as signaling molecules that begin the process of muscle protein synthesis. Muscle protein synthesis is the body’s main process responsible for building muscle. In fact, research has shown that free radical production during exercise is necessary to maximize gains. 2-3,6 Listed below we will examine some evidence as for why antioxidant supplementation interferes with muscle growth.
Evidence
One study found that when Vitamin C and E were given to subjects before resistance training it blocked one of the main pathways for satellite cell production. Satellite cells are important if you want to maximize muscle growth because they do two things. First, satellite cells repair damaged muscle and second, they join to build new muscle tissue. Therefore, satellite cells are critical if you want to maximize muscle development. 4,7 A similar study was performed also giving subjects Vitamin C and E before resistance training while the other group received a placebo (rice pills). At the end of this study, they found that the placebo group gained 25% more muscle than the antioxidant group.2 Finally, another study found if subjects supplemented with Vitamin C and N-acetyl-cysteine (another potent antioxidant) before resistance training they displayed a significantly lower muscle protein synthesis response compared to the group that received a placebo. 3 As previously mentioned, muscle protein synthesis is the main driver of muscle growth. This most likely means the individuals who supplemented with Vitamin C and N-acetyl-cysteine will have decreased muscle mass compared to the placebo group. Therefore, based on the evidence it seems antioxidants are detrimental to muscle growth by decreasing the natural process of free radical production from exercise. 2-3,6 Again, free radical production is needed to fully activate muscle protein synthesis, which maximizes muscle growth. 1,4-5,7
Timing
In conclusion, consuming supplemental antioxidants around exercise is a bad idea if you want to maximize muscle growth. If you must consume antioxidants around training I would aim for whole food sources such as fruits and vegetables. This is because antioxidant concentrations are much lower in food than in a supplement. This way you still get the health-promoting benefits of antioxidants without affecting muscle growth.
References
1. Barbieri E, Sestili P. Reactive oxygen species in skeletal muscle signaling. 2011. 2012;2012:1-17.
2. Bijornsen T, Salvesen S, Berntsen S, et al. Vitamin C and E supplementation blunts increases in total lean body mass in elderly men after strength training. Scandiveain Journal of Medicine and Science in Sports. 2016;26:755-763.
3. Childs A, Jacobs C, Kaminski T, Halliwell B, Leeuwenburgh C. Supplementation with vitamin C and N-acetyl-cysteine increases oxidative stress in humans after an acute muscle injury induced by eccentric exercise. Free Radical Biology and Medicine. 2001;31(6):745-753.
4. Gomes E, Silva A, Oliveira M. Oxidants, antioxidants, and the beneficial roles of exercise-induced production of reactive species. Oxidative Medicine and Cellular Longevity. 2012;2012:1-12.
5. Ji L. Modulation of skeletal muscle antioxidant defense by exercise: Role of redox signaling. 2007. 2008;44:142-152.
6. Morrison D, Hughes J, Della Gatta PA, et al. Vitamin C and E supplementation prevents some of the cellular adaptations to endurance-training in humans. 2015. 2015;89(2015):852-862.
7. Schelle C, Nielsen S, Pendersen BK. ROS and myokine promote muscle adaptation to exercise. Trends in Endocrinology and Metabolism. 2008;20(3):95-99.