Oxygen is one of the most essential chemical elements in the universe and it is the third most abundant one after hydrogen and helium. Oxygen is highly reactive can can become part of potentially damaging molecules called free radicals. Free radicals are molecules that are highly reactive because they have an unequal balance of charges. Free radicals can be produced during normal cellular metabolism and by exposure to toxins like cigarette smoke, pollution and some drugs. Since free radicals have unpaired electrons, they are unstable and reactive. Free radicals want to have an even number of electrons and will therefore take electrons from other molecules to do make this happen. This is to say that free radicals will oxidize other molecules to make themselves more stable. When this reaction occurs it can set off a chain reaction causing thousands of free radicals reactions within a few seconds. The effects of this can be quite damaging to our bodies. If our DNA becomes oxidized it can become broken and damaged causing potential mutations in genes and possibly leading to cancer. Free radicals can also cause damage to biological membranes and proteins in our body. Antioxidants can protect us from these harmful effects by donating an electron and creating a stabilizing effect on the free radical.
Oxidative stress is a state of imbalance between the pro-oxidants and the anti-oxidants. To reduce oxidative stress, a diet high in antioxidants can be very beneficial. Foods that contain vitamin C, vitamin E and beta carotene which the body converts to vitamin A are high on the list. It is important to note that a diet that is low in fat can impair the absorption of beta carotene and vitamin E because they are fat-soluble meaning they need fat to be absorbed by our body. Unlike water soluble vitamins like vitamin C that enter directly into your bloodstream, fat soluble vitamins are absorbed through the intestinal wall into the lymph system and then to the bloodstream where they are either used or stored in liver and fat cells. When the body needs these vitamins they are released from their storage sites.
In addition to these vitamins, there are many phytonutrients, which are compounds derived from plants, that are known for having an antioxidant effect. Flavonoids are a family of such compounds found in plants that occur naturally in fruit, vegetables, chocolate and beverages like wine and tea. Foods are given an ORAC score which stands for oxygen radical absorption capacity. High scores are given to goji berries, blueberries, dark chocolate, artichokes, pecans, cilantro, kale, strawberries and wild caught salmon among others. Herbs such as cinnamon, oregano, ginger and turmeric also score high.
Additionally, our bodies are equipped with mechanisms to protect us from oxidative stress through enzymes such as glutathione peroxidase, catalase, and superoxide dismutase. The trick to these enzymes working effectively is that they require certain micronutrients to perform their duties. These micronutrients include selenium, iron, copper, zinc and maganese. Whole grains, leafy greens, nuts, grass-fed beef and chicken can be good sources.
The take away?
Consuming a diet high in plant foods and including a rainbow of colors can offer a protective effect against the oxidative stress our cells are exposed to. This can help to “slow” the aging process and help to protect against diseases such as cancer, heart disease.
McGuire, M., Beerman, K. (2013). Nutritional Sciences From Fundamentals to Food, 3rd ed. Wadsworth. Belmont, CA.
Mandal, A. (2016). What are Antioxidants? Retrieved from http://www.news-medical.net/health/What-are-Antioxidants.aspx.
Linus Pauling Institute. Retrieved from http://lpi.oregonstate.edu/mic/dietary-factors/phytochemicals/flavonoids.
Linus Pauling Institute. Retrieved from http://lpi.oregonstate.edu/mic/minerals/manganese