Antioxidants and Athletes

Antioxidants, what are they, do we need to take them and how much? A few years ago, I would have said antioxidants were a new “buzz word.” People weren’t sure exactly what they were, but they knew they must be important to take. I could be wrong, but I think some of the buzz has died down around them in the general public. They know they need to take them, but it isn’t a headline article every day. That’s been replaced with gluten free. Athletes on the other hand, speak often about them. And for good reason as exercise produces free radicals, which can cause harm to the body. For endurance athletes who train often, this can lead to them thinking they need to supplement for protection.

In fact, I won’t mention the name of the company, but I have had two athletes approach me about a new antioxidant supplement they were taking. It is also a multi-level marketing company where you need to “buy in,” and then you get others to buy from you. I am not a fan of multi-level marketing companies, but I was interested in the product, so I looked at it. It is a mega dose of antioxidants with little research behind it. Just what I call “smoke and mirrors” marketing. Knowing that athletes are buying these supplements, made me look further into them. Is there truth behind their claims?

Antioxidants– man-made, or natural substances that prevent or delay oxidative stress. When the body under goes stress (like exercise and other daily functions), free radicals are produced which creates cell damage or death. In order to combat the free radicals, antioxidants are used to bind to the free radicals, stopping their reaction. In addition to cell damage from exercise, oxidative stress has been linked with cancer, so they are something that researchers are looking into further. Antioxidants are found in fruits and vegetables as well as dietary supplements. Some examples include-Vit. C, Vit. E, Beta-carotene, and Lycopene.

Since I’m not a cancer researcher I’ll leave the cancer studies to the real experts. I will speak more to athletes, and if we have seen a positive or negative link to athletes consuming mega doses.

Reasons to Supplement with Antioxidants:

  1. Exercise increases  oxidative damage to skeletal muscles. The higher the intensity of the exercise, the more oxidative stress.
  2. Athletes may consume less than the RDA (recommended daily allowance) of antioxidants.
  3. Some athletes believe that antioxidant supplementation improves performance.

The first two points I do not dispute. The research is clear that exercise does increase oxidative stress, and cellular damage. And it also true that a lot of athletes do not each the recommended foods in their diet. That being said, is there evidence for improved performance? Maybe….

MB Reid, in the Handbook of Oxidants and Antioxidants, Elsevier, 2000 showed that very few studies actually showed an increase in performance. The studies that did show an increase in performance were likely due to athletes that were deficient in antioxidants prior, taking a supplement and bringing them up to the levels of RDA. That being said, there are 2 antioxidants that have shown some potential for improved performance.

N-accetyl-cysteine (NAC)-Until 1994, NAC was a prescription drug regulated by the FDA. It is now an over the counter drug used to treat acetominophen poisoning. NAC is a thiol compound and serves as a cysteine donor for the synthesis of glutathione. Glutathione is an antioxidant. Two studies, have shown a small but significant improvement in performance when taken prior to exercise. Data showed the biggest benefit with submax exercise as well. Reid, et al. J Clin Invest 94:2468-2474, 1994. There was an additional study done in the 2006 in the Journal of Physiology.

Quercetin- A flavonoid or plant pigment found in fruits, veggies, leaves and grains. There have been non exercise studies done showing benefits with asthma, cancer, inflammation and autoimmune diseases. On the exercise side of things, a meta analysis by Millard-Stafford at el. 2010 showed improved performance in humans. Nieman et al. 2010 also showed a small but significant improvement of 2.9% in humans.

There are no known values for taking either of these compounds, so I won’t list any. This is more for your benefit of knowing that these two are showing promise.

Reasons to Not Supplement with Antioxidants:

  1. Exercise increases skeletal muscle antioxidant capacity and protects itself from contraction induced oxidative injury.
  2. High levels of antioxidants can promote muscle contractile dysfunction
  3. Antioxidant supplementation could blunt the exercise induced training effect.

Both rodent and human studies have shown that endurance exercise rapidly increases the antioxidant capacity of muscle cells. After 5 consecutive bouts of exercise, that is enough to see an improvement in antioxidant enzyme capacity and protect the muscle. Powers and Jackson, Physiological Reviews, 2008. Coombes et al. 2001, showed that supplementation with Vit. E, impaired the muscle force production, meaning it produced a weaker contraction. Not a good thing for athletes.

Finally, multiple studies have shown that supplementing with antioxidants is counter productive to looking for the exercise induced adaptations from exercise. When we exercise, we create muscle inflammation and damage. As we recover we make ourselves stronger, faster, etc. If you were to blunt this effect, you would not see training adaptations. Gomez-Cabera Am J Clin Nutri. 2008.

You can see that there are reasons to supplement, and reasons not to supplement. The takeaway for you, is:

If you are eating a diet rich in fruits and vegetables, and bright in color (berries, red peppers, tomatoes, etc), you are getting a healthy dose of antioxidants. If you are not, you should change how you are eating to incorporate these, and not take a supplement. As more and more research is done, we can watch and see what might be a good supplement to try in the future. But for now, just eat a healthy dose of fruits and veggies and save your money.

I thought I would include a recipe for a delicious fruit smoothie, rich in antioxidants. I love smoothies and routinely have them for breakfast. In honor of IM Lake Placid yesterday, I chose my LP finisher glass. Congrats to all the finishers, the weather was less than desirable, at least in the morning.

Berry Smoothie

Berry Smoothie

Berry Smoothie, for 1

  • 1 cup of fluid-I use water while I’m not exercising, but milk-soy, almond, skim is fine
  • 1 cup of plain non fat greek yogurt
  • 1/2 banana
  • 1 cup of frozen berries
  • 1/2-1¬† tbsp ground chia seeds ( I just spoon some in)
  • 1/2 tbsp almond/peanut butter
  • extra ice if needed
  1. Place ingredients in the blender and blend for :30-60 depending on the power of your blender. Add extra ice if needed.

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