Antioxidants

What runners need to know

While running offers a multitude of health benefits, such as building strong bones and improving cardiovascular fitness, it also results in the production of free radicals, which are unstable and highly reactive molecules that steal electrons from healthy cells in an effort to become stable, and in the process, cause cell damage. If there is a disturbance in the balance of free radicals and the body’s defence mechanism against them, oxidative stress can result, which may lead to an inflammatory response and is linked to cardiovascular disease and cancer.

This is where antioxidants come in. Antioxidants defend against oxidative stress by neutralizing free radicals. They may be endogenous (occurring naturally in the body) or exogenous (from food, drinks and supplements). Examples of antioxidants include vitamin E, vitamin C, selenium, carotenoids and flavonoids. No single antioxidant is more important than another, as they work together to defend against oxidative stress. Likewise, there is no single food or beverage with the perfect amount of antioxidants. Some examples of antioxidant rich foods include:

» FRUITS AND VEGETABLES: kale, artichokes, strawberries, blackberries

» NUTS: walnuts, pecans, sunflower seeds

» HERBS AND SPICES: cloves, cinnamon, all spice, oregano, thyme, rosemary

» OTHER: Items such as green and black tea, coffee, red wine, dark chocolate

Given that exercise increases the production of free radicals, it would make sense that runners would have increased antioxidant requirements. As a result, antioxidant supplements are often promoted for runners, to reduce muscle damage and improve performance. However, runners may want to hold off before taking an antioxidant supplement. Here’s why:

Runners may not have increased antioxidant needs

Despite the increased free radical production that comes with exercise, runners may not have increased antioxidant needs, because regular running increases the body’s endogenous antioxidant systems. This means that, with regular running, our body is better able to deal with the free radical production from exercise.

Antioxidant supplementation may decrease performance and harm health

The free radicals produced from exercise may lead to muscular adaptations that, with time, lead to improved performance. As a result, taking an antioxidant supplement may blunt the training adaptations. Beyond the impact on performance, even more concerning is the effect of high doses of antioxidants on health outcomes. For instance, there is a link between high doses of betacarotene (an antioxidant) and the risk of lung cancer.

Antioxidant supplements are not the same as antioxidant-rich foods

Whole foods contain natural antioxidants in natural ratios and proportions that can’t be replicated in pill form. For instance, there are eight different forms of vitamin E found in food, yet, most vitamin E supplements will include only one of these forms. There may also be other health-promoting substances in foods that won’t be present in a supplement.

The bottom line: athletes should aim to consume an antioxidant-rich diet, rather than taking an antioxidant supplement. Taking high doses of an antioxidant through supplemental form may be detrimental, rather than beneficial, to performance and health, by blunting training adaptations. While antioxidants defend against the free radicals produced from running when it comes to dietary antioxidants, there can certainly be too much of a good thing.