Antioxidants work by neutralizing harmful free radicals and protecting the body against decomposition.
About free radicals
A free radical is most often an oxygen atom or a similar substance which has lost one or more electrons causing it to be unstable. This loss of electrons causes free radicals to steal electrons from nearby molecules, which in turn become unstable and are forced to steal electrons as well. A free radical only exists for a fraction of a second, but this is enough time for it to cause a chain reaction of unstable molecules which damage (dissolve – decompose) cell membranes, nearby tissue, and in some cases the cells’ hereditary information (DNA). An electron transfer which occurs like this is called oxidative stress, even when it is not caused by oxygen molecules.
We constantly create free radicals in our body while under physical activity and when we are exposed to radiation, sunlight, stress, pollution, heavy metals, tobacco smoke, alcohol, medicine, infection, and so on. Even the liver’s detoxifying process causes the formation of free radicals, which increases the body’s need for antioxidants, vitamins, minerals, and amino acids.
Cells have repair mechanisms which can repair most damage, but some damage after exposure to free radicals remains. This can cause the formation of a cancer cell
The more our lives are strained by the above mentioned activities, the more free radicals are produced. The body has some enzymes, including superoxide mutase (SOD), glutathion peroxidase, and catalase, which can neutralize free radicals, but their capacity is limited. Therefore we require regular supplements of zinc, copper, iron, manganese, and selenium (among others), which are necessary for the aforementioned enzyme systems, and we need antioxidants.
Plants produce antioxidants to protect them from the harmful effects of sunlight. The more extreme a plant’s environment, the more antioxidants it produces. We benefit from these antioxidants by consuming such plants.
Antioxidants have a property which enables them to give off electrons to free radicals whereby they protect the cellular environment from damage. Under this process they, sooner or later, lose their antioxidant effect and must be either regenerated or resupplied.
There are many different antioxidants. Some are water soluble, such as vitamin C, while others, like vitamin E, are fat soluble. Some antioxidants work only inside the cells while other work only outside. Some work only in eye tissue, and so on. We need them all. Supplementation of a single antioxidant is not sufficient, even if the dosage is very high. Antioxidants work in congress and repair each other when they are damaged in their battle against free radicals so that they work once again. Vitamin C repairs vitamin E and the reverse. Lipoin acid also repairs other antioxidants, as well as bioflavonoids.
The effects of free radicals can be seen when halved apples and avocados change from their fresh colours. If one drips lemon juice (an antioxidant) onto these fruits, no colour change occurs. The browning of an avocado or apple is caused by the theft of electrons from the surface of the fruit by the oxygen in the air. Oxygen can react with extra electrons. The vitamin C in lemon juice delivers electrons to the oxygen atoms’ attack and thereby protects the fruit.
Throughout the last 50 years, antioxidant research has shown light onto a long list of factors. In recent years the medical community has begun to realize that it is possible to lessen some of the strains on society and even to cure some illnesses with the use of antioxidants.
Antioxidant insufficiency is especially seen in:
- Elderly, who do not eat very much
- All people who lack varied diets
- People with chronic disease
- Athletes
- People with physically hard jobs
- People who suffer from stress
- Alcoholics and smokers
- People strained by medicine and other chemicals
Healthy food is known for containing a large amount of antioxidants. The best dietary sources of antioxidants are fruits and vegetables. Both black and green tea contains very high amounts of antioxidants. Vegetables of the cabbage family top the list of antioxidant containing vegetables.
It is recommended that one intakes large amounts of antioxidants daily. Taking large amounts of a single antioxidant for longer periods without supplementing with a balanced supplement of vitamins and minerals is however not recommended. Therapy with a single antioxidant can in the worst cases cause cellular imbalances which can cause unforeseen oxidative stress. It is good to take many different antioxidants because they greatly increase each others’ effectiveness. All of the most important antioxidants can be found in good multivitamin – mineral supplements.
The most important antioxidants and substances with antioxidant effects:
- Beta carotene
- Vitamin C
- Vitamin E
- Vitamin B6
- Vitamin B1 - has antioxidant effects
- Vitamin B2 - has antioxidant effects
- Vitamin B3 - necessary in certain antioxidant enzymes
- Vitamin B5 - has antioxidant effects
- Selenium - necessary in certain antioxidant enzymes
- Zinc - necessary in certain antioxidant enzymes
- Copper - necessary in certain antioxidant enzymes
- Manganese - necessary in certain antioxidant enzymes
Other substances with antioxidant effects
- Co-enzyme Q10
- Superoxide dismutase (SOD)
- Glutathione
- Alpha lipoic acid
There are several hundreds of substances with antioxidant effects, for example some amino acids and flavonoids which can be found in fruits and vegetables.
Also see "Multivitamins-minerals".
