Antioxidants are substances found in food – i.e. plants and animals – that inhibit the chemical process of oxidation. Oxidation is the chemical process of one chemical “taking” electrons from another chemical. This is a natural reaction and necessary for life but oxidation can also be destructive.
It’s All About The Free Radicals
No, free radicals are not some new punk band or fringe political movement; we are talking about free radical chemistry here. Free radicals are unstable molecules that are missing an electron making them highly reactive. Free radicals take electrons from stable molecules. As I stated before, when a substance takes electrons from another substance, it is called “oxidation.”
Free radicals being produced by a mitochondrion during oxidation. Mitochodria are the "power plants" of our cells.
Oxidation is not generally a problem. The problem caused by free radicals is that the free radicals set off a chain reaction. When one free radical takes an electron from a compound, that compound also becomes a free radical setting of an electron snatching frenzy with free radicals producing more free radicals. Once a free radical is formed, it is immediately on the look out to take an electron to fill that lonely spot.
Superoxide: a common free radical. Notice the missing electron on the left oxygen atom. That lonely electron is what is looking to take an electron from another substance.
Free radicals are implicated in the development cancers, atherosclerosis, emphysema, and the aging process itself. In fact, there is a “Free Radical Theory of Aging.” It states that organisms age as a result of free radical damage over time. Even though there is a lot of science behind free radical oxidation, it remains to be seen just how important free radicals are in disease and and aging processes.
Antioxidants To The Rescue
Antioxidants deal with free radicals in a pretty straightforward way. Antioxidants are highly stable molecules that neutralize free radicals by “donating” one of their electrons to a free radical, thus stopping the free radical chain-reaction. Unlike other substances, antioxidants don’t become free radicals once they have donated their electron because they are highly stable. Without going into the chemical mechanisms behind it, antioxidants stop free radicals by giving up an electron but they remain unaffected by the electron loss.
There are many antioxidants, but here is a list of the most common ones and a few examples of where they are found:
- Vitamin A and Beta-Carotene: excellent sources include sweet potatoes, carrots, broccoli, and beef liver.
- Vitamin C: excellent sources include red bell peppers, broccoli, strawberries, kiwi fruit, and brussels sprouts.
- Vitamin E: found in nuts, seeds, egg yolks, liver, and leafy green vegetables.
- Selenium: found in seafood and meat. Selenium is also found in vegetables fruits and grains, but the amounts are dependent on how much selenium was in the soil where they were grown.
Take-Away Points
Although the scientific jury is out on just how important antioxidants and free radicals are in the development of disease and aging, there is plenty of evidence on how important it is to eat fruits and vegetables. Meat, eggs, and dairy may be a more controversial topic as to the health benefits vs. risks, but there are plenty of good nutrients, including antioxidants, found in them as well. Let’s sum up like this:
Eat your fruits and vegetables with some eggs and lean meats thrown in for good measure!
Main Image: Suat Eman / FreeDigitalPhotos.net
