Antioxidants (molecules that inhibit oxidation) play a central role in the body. They are, in fact, critical for life. Without them the cells in your body would soon be damaged beyond repair.
A cell can be damaged, or mutated in several ways. Mutations usually occur when defects are created in DNA, which result in the production of defective or incorrect proteins. Many of these defects are caused by what are called free radicals. Free radicals are associated with oxygen and since we breathe in oxygen continuously, there’s plenty of it in our bodies at any time. Basically, they are oxygen molecules that are missing an electron and are looking to snatch one from another molecule in a process called oxidation.
Despite the damage they do, free radicals play an important role in nature. An exposed apple decays and dries up and iron bar eventually rusts and disappears because of them. So nature uses them to get rid of things that are no longer needed. In the body however, they can be a disaster. As you might expect, the body is programmed to get rid of them. To do this it uses antioxidants – a highly efficient process – but sometimes a few manage to elude the antioxidants and they can cause considerable damage. Strangely though, they are helpful in some cases. The immune system for example, uses them to fight infection.
But how does oxygen lose an electron and become a free radical? There are several ways. Radiation is one. Others include cigarette smoke, smog and various chemicals. Free radicals are even generated when you exercise. In addition, large numbers are produced in the “furnaces” within your cells, called mitochondria. They generate the energy that your body needs each day.
The large number of free radicals within mitochondria are, in fact, a serious problem because mitochondria has its own DNA called mtDNA, which direct everything that goes on within it. And with so many free radicals around, the mtDNA is particularly vulnerable and gets attacked continuously.
Oxidative Stress and Disease
The constant production of large numbers of free radicals in the normal course of metabolism, plus other pressures from the environment – like toxins in the air and water – places a heavy burden on our organisms, since they damage all components of our cells, including DNA, protein, cell membranes and lipids. This produces what is called oxidative stress and because it causes considerable damage to our cells and it can cause cell death. It is now thought to be involved in many diseases such as cancer, Alzheimer’s disease, Parkinson’s disease, autism, MS and others.
Oxidative stress also causes the oxidation of LDL cholesterol, which is a precursor to plaque formation and heart disease. And, it has been shown to be implicated in chronic fatigue syndrome.
Free Radicals and Aging
Free radicals are also now assumed to be related to the aging process, although there is some controversy about exactly how they are related. A theory referred to as the “Free Radical Theory of Aging” was put forward in the 1950s by Dunham Harman. A few years later it was modified to include several diseases such as cancer, Alzheimer’s, Parkinson’s, diabetes and several others. Then in 1972, Harman introduced his “Mitochondrial Theory of Aging” in which free radicals acting on mitochondrial DNA played a central role in aging. Although there’s no doubt that free radicals play some role in aging, the problem with these theories is that dietary and supplements of antioxidants, which should control the free radicals that are produced, do not appear to extend our life, or even decrease the incidence of disease. The main problem at the present time is that we do not yet fully understand all the details of how free radicals, or even antioxidants, act in the body.
Having a good supply of antioxidants in your body is critical, and there are three ways you can get them: through the food you eat; through supplements; and, your body also produces some.
Some of the major antioxidants are:
- Glutathione is synthesised in your body from amino acids. It is one of the most important cellular antioxidants and is found in all cells.
- Alpha Lipoic Acid is also present in all cells in your body. It is used in the conversion of glucose (blood sugar) into energy. It also helps recycle several antioxidants when they are used up.
- Selenium is not directly an antioxidant but is required to initiate the activity of some antioxidants. It also helps in the production of glutathione.
The Best Sources of Antioxidants
Although you can get antioxidants both from food and supplements, it is best to get them from food. The best food sources are vegetables and fruits (it’s important to note, however, that processed food contains fewer antioxidants than fresh or uncooked foods.) Other types of foods that contain smaller amounts are nuts and whole grains; with even small amounts in meat, poultry fish, eggs and coffee.
The Controversy with Supplements
Vitamins C, E and A, along with selenium, grape seed extract, pycnogenol and resveratrol are all well-known antioxidant supplements. Recent studies have shown that there are problems with antioxidants in supplement form. They show that supplements don’t appear to extend life, nor do they appear to be directly helpful in relation to most serious diseases such as cancer. Indeed, if taken in large amounts they may even have an adverse effect. This is strange in that fruits and vegetable that contain large amounts of antioxidants are particularly good for you and do appear to ward off some diseases. The reason that fruits and vegetables are so much better, according to most scientists, is that they contain large numbers of other excellent nutrients besides antioxidants, which also likely have an effect.
A few antioxidants however, do appear to be directly helpful. Lipoic acid for example, seems to protect mitochondria and studies have shown that it is also helpful in slowing macro degeneracy of the eyes.
Significant of Antioxidants in Relation to Exercise
Large numbers of free radicals are also created when you exercise and they produce oxidative stress that can last up to 24 hours after the exercise. During exercise, many muscle cells break down and die and must be replaced. They’re usually replaced by larger and more powerful cells. Antioxidants play important roles in this process. But, strangely, free radicals are also used for removing dead cells and if there are too many antioxidants present, they can delay recovery.
So, the role of antioxidants in relation to exercise is a mixed bag. You don’t want too many, but they are used by the immune system and they also help strengthen the glutathione system, which helps decrease oxidative stress.