Antioxidants are one of the most commonly used buzzword in health and fitness reporting. Almost every wellness product is “loaded with antioxidants” so to speak. The necessity of antioxidants for our health and well being is well understood. However, are they always a good thing? Do they have any benefits beyond their recommended daily intakes ? Does supplementation with antioxidants actually help? Do they improve or impair athletic performance? Can one get sufficient antioxidants from the diet? These are some of the questions which one maybe tempted to ask when analyzing the health benefits of antioxidants. Before proceeding to analyze the pros and cons of antioxidants, let us understand the role they play in our body.
The role of antioxidants in our body
Oxygen is one of the elements which is needed for human survival. So how does it become a liability inside our body? Oxygen in our body splits into atoms with unpaired electrons known as known as reactive oxygen species or ROS . ROS comprises of both free radicals and non free radicals. Electrons prefer to be in pairs, hence ROS are always looking out for electrons from other atoms. They target the DNA, proteins and cells causing damage. Free radicals in particular have been associated with chronic diseases such as cardiovascular diseases, cancer and neurodegenerative disorders such as Alzheimer’s . Free radicals are generated within our body as well as found in our food and the water we drink , additionally they also enter our body through environmental exposure and through pesticides.
As ROS can cause cellular damage , the body needs to maintain a balance and prevent it from happening. This is achieved through antioxidants present in our diet. The mechanism of how antioxidants scavenge unpaired electrons from free radicals has been covered in an earlier blog post on Vitamin C and its role in chronic diseases. Fig 1 demonstrates how antioxidants scavenge electrons from free radicals. While the role of antioxidants maybe useful in prevention of chronic diseases, excess antioxidants are not always a good thing. Some researchers have even questioned if the role of dietary antioxidants are significant or not.
Exercise and oxidation: Are Reactive Oxygen Species indeed the villains?
Exercise requires a greater intake of oxygen than day to day activities such as sleeping, walking and sitting. Hence, one maybe tempted to think our body undergoes severe oxidative damage. However, if this were to be the case wouldn’t those who exercise frequently be suffering from heart disease, stroke and DNA damage ? On the contrary, those who exercise are actually healthier. Hence, this is one of the cases where the evidence does not back up a theoretical assumption. Excessive oxidation needs to be prevented, that is undisputed. However, our body has mechanisms to do so. Scott Powers and colleagues argue that dietary oxygen can be used only once to counter oxidative damage. Whereas antioxidant enzymes in our body are capable of handling the constant oxidative stress during periods of intense exercise.
Evidence that has emerged over the last decade has indicated that ROS plays an important role in signaling mechanisms for training adaptation. Hence low doses of ROS is not a bad thing ! The free radical buzzword you come across everywhere on the internet and health related TV shows is not always a villain! ROS act is critical signalling molecules for initiating muscle growth after a workout. Gomez and colleagues have argued against supplementation with antioxidants as being “worse than useless”, based on the fact that positive benefits of ROS are countered with dietary antioxidants.
Key takeaways for Athletes :
Based on the existing evidence atheletes should keep the following points in mind
- Reactive oxygen species especially free radicals are not always harmful in small quantities and are needed for training adaptations. They act as important signalling molecules for muscle growth, recovery and protein synthesis.
- Our body has antioxidant enzymes. A diet rich in fruits and vegetables will provide us with sufficient antioxidant needed to prevent cellular damage.
- There is no benefit in excessive antioxidant supplementation. On the contrary it harms training adaptations . Athletes are more likely to be negatively impacted by antioxidants.
- There is no evidence that antioxidants help in recovery after a workout.
- There is no evidence that antioxidants can boost performance.
Antioxidants are not proven to help in athletic performance. On the contrary athletes are encouraged to avoid antioxidant supplementation as it can cause more harm . A diet rich in fruits and vegetables will provide the needed antioxidants.
The key take home message for athletes is the fact that too much of a good thing is not always ideal. Antioxidant supplementation is unnecessary. I have previously argued that supplements are not always beneficial especially if the nutrients can be obtained through our diet. This is a prime example of the same.