Antioxidants are a broad range of vitamins and phytonutrients widely marketed for general health and anti-aging. The most common nutrients sold as antioxidants are vitamins C and E, though preparations of endogenous antioxidants such as melatonin and glutathione are also becoming popular for use as a supplement. Before we can discuss the pros and cons of these supplements, we must first examine the chemistry and logic underlying their use.
Redox reactions are the chemical processes whereby an electron is removed or donated from one molecule to another. In oxidation, it is a loss of an electron, in reduction, a gaining. In biology, this typically occurs by the swapping of hydrogen or oxygen. If the molecule is scavenging for oxygen, it is known as an oxidizing agent or free radical; if it is able to donate oxygen, it is known as an antioxidant.
Free radicals (also known as reactive oxygen species) form in the mitochondria of our cells during normal detoxification processes. There are antioxidant mechanisms in place to quell this fire, but at times, an abundant buildup of free radicals can overwhelm the body leading to cellular damage. Anytime free radicals are allowed to buildup, there is a generalized increase in cellular damage and the potential for that damage to affect the DNA, resulting in abnormal mutation.
At the onset of applying these principles to human physiology, it was first assumed that reactive oxygen species (ROS) were categorically harmful. It was also theorized that the buildup of the ROS naturally generated during normal cellular detoxification reactions was a cause of aging, then posited as the free radical theory of aging.
Since then, science has broadened its understanding of ROS and has now identified their utility as messenger molecules in the body. Emerging research shows that endogenously generated ROS play a role in cellular signaling that create a beneficial change in the body. For example, it has been reported that antioxidant supplements may have a detrimental effect when consumed after exercise. In this instance, the oxidative stress induced from exercise signals a rebuilding phase in the body, ultimately resulting in the benefit derived from the body adapting to stress. Antioxidants appear to blunt this natural response to a beneficial stress.
In a similar line of thinking, there have been numerous studies, including a meta-analysis from the Cochrane Collaboration, that show a negative effect from taking antioxidant supplements. Juxtapose this with a litany of research showing positive outcomes of high-dose antioxidant therapy, and the waters get muddy fast.
Ultimately, the truth between these two sides rests in appreciating the complexity of the body. ROS are both beneficial and detrimental depending on the amount and context through which they are generated. This is called a hormetic effect, a principle which shows how the dose of a substance determines its biological response.
The basics of redox chemistry teach us that, depending on the environment, an antioxidant can become a pro-oxidant. This effect may be explained, in part, with the understanding that not all antioxidant supplements are created equal.
One antioxidant that has received a fair amount of criticism is vitamin E. Alpha tocopherol is considered the antioxidant aspect of the fat-soluble nutrient vitamin E; however, it exists in food as as a synergy of nutrients. Compare this with the isolated and often synthetic form (dl-alpha tocopherol) found in vitamin bottles.
Although clinical efficacy can be derived from using vitamin E in its isolated form, I feel very strongly that this therapy is more like a drug effect than a nutritional strategy. It’s in such a context where the line between antioxidant and pro-oxidant can become blurred.
If the goal is nutritional support of a gland or tissue, I feel it is a far more beneficial strategy to use a whole-food form of vitamin E, wheat germ oil for instance, which contains a complement of tocopherols and tocotrienols.
Although there is a place for high doses of certain vitamins for a period of time, a long-term health or anti-aging strategy should focus on nutrients, derived from food or herbs, that enable your body’s own antioxidant capacity. One pathway that has been studied in this regard is the Nrf2-ARE pathway.
The Nrf2-ARE pathway is an internal process within our cells that dynamically responds to chemical stresses, turning on and off as needed. Certain plants have a beneficial effect on this pathway and thus exert a positive global effect on oxidative stress. In addition to health and longevity, upregulating the Nrf2-ARE pathway exerts a neuroprotective effect that could help keep our brains young and healthy. Substances which effect this pathway would be a consideration for those suffering from the ravages of neurodegenerative diseases.
Many active phytochemicals from plants have been studied and found to induce a response in the Nrf2-ARE pathway. Some of those plants include green tea, turmeric, rosemary, and the compound resveratrol found in red wine and certain medicinal herbs.
In light of this research, we now know we have a choice in how to exert an antioxidant effect on the body. One option is to ingest antioxidants through supplements. The science is mixed on the effects of these compounds so attention to quality and dose within the context of one’s overall health is a must. The other option is to ingest natural foods and herbs that, although they may not be antioxidants themselves, cause an internal response resulting in the benefits derived from taking antioxidants.
The elegance of the latter strategy is the realization that we are working within the body’s design and at its own pace. Like exercise, which induces the body through the cellular signaling of ROS, we can proceed in an evolutionary consistent manner, offering our body the tools to self-regulate and heal in a profound and holistic way.