Antioxidants—we have heard the term over and over in the health and longevity spheres, but what are they, where can we find them, and why are they so important? Several of our food and supplement recommendations are geared towards increasing your intake of antioxidants, particularly vitamins A, C, and E.
Oxidative Stress and Antioxidants – Overview
An antioxidant is a compound that stops the oxidation of another compound. Oxidation is a naturally occurring, chemical process that causes the loss of electrons.
A compound that has been oxidized is called a free radical. It is very reactive – i.e., it needs to react to another compound as quickly as possible.
Some free radicals are produced from essential processes for survival, like ones from the metabolism of oxygen, other cellular activities etc. These are termed as reactive oxidative species or ROS. Others are produced as part of series of chemical reactions, where the next step of the reaction quickly converts the free radical to something else. Still, others may be produced from breaking down harmful environmental factors, such as ingredients in cigarettes.
Free radicals that do not have a scripted next step are the ones that are most damaging to our bodies. Here’s where antioxidants come in. They can either immediately neutralize free radicals, or they can interfere with the free radical’s path of destruction and prevent or reduce the amount of damage.1
Vitamin C, or ascorbic acid, is a water-soluble vitamin that cannot be stored in the body, so humans need to consume adequate amounts of vitamin C each day.
Vitamin C is primarily in fruits and vegetables—some of the best sources are citrus, bell peppers, dark leafy greens, kiwi, broccoli and strawberries.
Research has shown that vitamin C can significantly lower a key marker of oxidative stress and markers of inflammation.
It may also have a role in reducing severity and duration of common cold and as an immunity support.2
Vitamin E is another antioxidant and is a fat-soluble vitamin. It is a family of 8 different compounds, 4 tocopherols and 4 tocotrienols — all of which together when supplemented could lead to greater benefits across wider range of tissues and organs in the body.
Vitamin E – Overview of Evidence in Liver and Inflammation
Similar to vitamin C, vitamin E helps to manage the bodies’ level of oxidative stress. If the level of oxidative stress gets too high, we may not be able to prevent or protect against cell damage.1
One area in which vitamin E may be able to prevent cellular damage is in the liver. Oxidative stress in the liver could result in liver damage, which could elevate the level of two key liver enzymes – alanine aminotransferase (ALT) and Aspartate transaminase (AST). Oxidative stress in the liver could potentially be caused by various factors, including high alcohol intake, or high intake of fatty foods and excess calories.
Clinical studies indicate that high dose vitamin E supplement may help to improve biochemical parameters of liver health.4
Lobo V, Patil A, Phatak A, Chandra N. Free radicals, antioxidants and functional foods: Impact on human health. Pharmacognosy Reviews. 2010;4(8):118-126. doi:10.4103/0973-7847.70902.
Anna Floegel, Sang-Jin Chung, Anne von Ruesten, Meng Yang, Chin E Chung, Won O Song, Sung I Koo, Tobias Pischon and Ock K Chun (2011). Antioxidant intake from diet and supplements and elevated serum C-reactive protein and plasma homocysteine concentrations in US adults: a cross-sectional study. Public Health Nutrition, 14, pp 2055-2064.
Sanyal AJ, et al. Pioglitazone, Vitamin E, or Placebo for Nonalcoholic Steatohepatitis. The New England Journal of Medicine. 2010;362(18):1675-1685.