Free Radicals in the Body

Conceptual image of nutraceuticals.
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Free radicals are unstable molecules that can damage the cells in your body. They form when atoms or molecules gain or lose electrons. They often occur as the result of normal metabolic processes. For example, when your body uses oxygen, it creates free radicals as a by-product and the damage caused by those free radicals is called 'oxidative stress.'

But your metabolism isn't the only culprit. You can also be exposed to free radicals that come from various environmental sources such as radiation, drugs, pesticides, solvents, cigarette smoke and other pollutants.

Why Are Free Radicals So Bad?

When you're young and healthy, your body does a pretty good job of dealing with these free radicals, and you don't even notice anything. But, if you don't eat right, smoke, or are exposed to a lot of environmental sources of free radicals, your risk for cellular and organ damage goes up. Oh, and aging takes its toll on your free radical defense system too.

Free radicals damage cells over time, so eventually whatever organ those cells belong to isn't going to function quite as well as it should. For example, a connective tissue called collagen gets weaker with free radical exposure, and as a result, your skin gets more wrinkles. Also, the walls of your arteries can get damaged, and cholesterol plaques build up, which can reduce blood flow to your heart, brain, and other organs, or cause blood clots. 

Because of the potential damage, excessive free radical exposure is associated with an increased risk of many chronic diseases, such as heart disease and some forms of cancer.

Obviously, it's an excellent idea to avoid excessive amounts of free radicals.

That Covers the Chemistry and Health, So What Does Nutrition Have to Do With It? 

Eating healthy foods, especially colorful fruits, and veggies may help combat some of the free radical damage. Nutrients such as vitamin C, beta-carotene, selenium and vitamin E may help prevent or reduce the damage caused by free radicals, so they're called antioxidants.

These nutrients are found in a variety of foods, but they're highest in plant sources. So that may be one reason why eating a diet rich in fruits and vegetables is so important for your health.

Indeed, studies show that eating a diet high in antioxidants is associated with better health. Of course, there are other reasons why people who have a high intake of antioxidants might be in better health. For example, individuals who eat healthily also tend to be more physically active and more likely to maintain a proper caloric intake. 

Can Dietary Supplements Fight Free Radicals?

There are so many dietary supplements that claim to be antioxidants because they're made of nutrients or plant extracts that have demonstrated antioxidant activity in a laboratory. But, although eating foods rich in antioxidants appears to be beneficial, taking antioxidant supplements doesn't seem to offer the same benefits, except in rare cases. Like the combination of lutein, zeaxanthin, and other nutrients that may slow down the progression of macular degeneration, which is the leading cause of blindness in the elderly.

Although antioxidant supplements are generally regarded as safe, some research studies suggest that taking certain antioxidant supplements can do more harm than good, which isn't what you want if you're trying to get or stay healthy.

So, rather than spend money on expensive dietary supplements, you're probably better off to buy more fruits, vegetables, and other healthy foods.

Sources:

Broadhead GK, Grigg JR, Chang AA, McCluskey P. "Dietary Modification and Supplementation for the Treatment of Age-related Macular Degeneration." Nutr Rev. 2015 Jul;73(7):448-62.

Harvard T.H. Chan School of Public Health, The Nutrition Source."Antioxidants: Beyond the Hype." 

Lobo, V. et al. "Free Radicals, Antioxidants and Functional Foods: Impact on Human Health." Pharmacognosy Reviews 4.8 (2010): 118–126.   http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3249911.

National Cancer Institute. "Antioxidants and Cancer Prevention."

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