Ranging from fruit-based extracts to vitamins and fatty acids, antioxidants are common in dietary supplements for sports and active nutrition, . However, scientific evidence validating benefits for some of these ingredients is lacking.
Thus, the International Society of Sports Nutrition (ISSN) published a stance on antioxidants that outlines its evidence-based approach to recommendations on this ingredient category.
The ISSN reviewed and analyzed the clinical substantiation (or lack thereof) for several antioxidant ingredients, including letter vitamins, botanical extracts, amino acids and fatty acids.
Key points from the stance are:
A spectrum exists for oxidative stress. Whereas a little stress (eustress) can be beneficial, too much can cause issues including inflammation and muscle damage.
Dietary antioxidants can manage oxidative stress, but evidence is not conclusive for all antioxidant ingredients.
Whole foods are the preferred antioxidant source, but supplements do have a place for intense training or dietary insufficiencies.
Antioxidant use should be tailored to individual needs and training regimens.
Ingredients with solid benefits for sports nutrition include omega-3 fatty acids, astaxanthin and tart cherry.
Why did the ISSN take a position on antioxidants?
“The ISSN, as an academic-oriented sports nutrition society, publishes a number of position stands, which are basically the synthesis of evidence-based research that then is distilled into useful and applicable tidbits for consumers, coaches, registered dietitians, athletic trainers and the populace,” said Douglas Kalman, Ph.D., R.D., clinical associate professor at Nova Southeastern University and ISSN cofounder.
Kalman noted exercise induces oxidative stress and produces free radicals, which in turn cause cytokine inflammatory responses.
“If exercise induces oxidative stress, will antioxidants help enhance recovery? And can they positively impact performance as well?” Kalman asked.
Antioxidants are often considered a remedy to oxidative stress and neutralizing free radicals within the body. While some oxidative stress is beneficial and improves cell adaptability, too much oxidative stress could be harmful.
“We know that there is a correlation between the effects of oxidative stress on the body over time and incidence and occurrence of a variety of various diseases, cardiovascular and neurological,” Kalman said.
Can too much of a good thing be bad?
While antioxidants can reduce inflammation and delay muscle soreness, there is a point at which too much of a good thing can have a negative impact.
“There is such a line of demarcation where an antioxidant actually can become a pro-oxidant,” Kalman said, citing vitamin C as an example.
“Vitamin C at lower doses has antioxidant behavior, and it is a known antioxidant” he said. “But at higher concentrations, it actually induces oxidative stress and oxidative damage.”
While Kalman acknowledges athletes are a bit of a microcosm, he stressed the importance balancing oxidative stress without completely shutting it down.
“We have our normal ebb and flow stress response … so we need to allow that without dampening it so much to turn it off,” Kalman said. “There’s a balance there (with) antioxidants and oxidative stress.”
Can everyone, not just athletes, benefit from antioxidants?
“The answer is yes,” Kalman said.
He shared that antioxidants that are scientifically backed for supporting athletes also have other health benefits, such as naturally occurring melatonin in tart cherry or how astaxanthin supports eye health.
While the ISSN position supports a food-first strategy, Kalman acknowledged the benefits that antioxidant supplements have for many facets of human health.
Kalman also mentioned creatine as something that can benefit everyone and not just athletes, noting that creatine is an atypical antioxidant. Both consumers and researchers have given creatine a great deal of attention outside the sports sector.
When asked what ingredients he sees emerging for sports nutrition in the future, Kalman cited pomegranate, ashwagandha and urolithin A, although more studies are needed to determine their benefits for athletic performance and recovery.
