How Free Radicals Damage the Body

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Free radicals are unstable molecules or atoms that can damage the cells in your body. They form when atoms or molecules gain or lose electrons, resulting in an unpaired electron. The free radicals collide with your cells in an attempt to "steal" an electron, and the cells that lose electrons may start to malfunction.

Free radicals often occur as a 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, cigarette smoke, and other pollutants.

What Do Free Radicals Do?

If you're young and healthy, your body does a pretty good job of dealing with these free radicals, and you likely won'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. 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 as well as it should. For example, connective tissue called collagen gets weaker with free radical exposure and, as a result, your skin gets more wrinkles.

The walls of your arteries can get damaged, and cholesterol plaques accumulate, which can reduce blood flow to the heart, brain, and other organs, or it can cause blood clots. 

Excessive free radical exposure is associated with an increased risk of chronic diseases, like heart disease and cancer. Taking steps to avoid free radical exposure, and boosting your antioxidant defenses, can help reduce your risk.

How Does Nutrition Impact Free Radicals? 

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 free radicals from harming cells and reduce oxidative stress, 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. Individuals who eat healthily also tend to be more physically active and more likely to maintain proper caloric intake.

Can Dietary Supplements Fight Free Radicals?

Many dietary supplements claim to be antioxidants because they're made of nutrients or plant extracts that have demonstrated antioxidant activity in a laboratory. 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.

One of these cases is the combination of lutein, zeaxanthin, and other nutrients that may slow the progression of macular degeneration, which is the leading cause of blindness in older individuals.

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. Rather than spending money on expensive dietary supplements, you're probably better off buying more fruits, vegetables, and other healthy foods.

7 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Shereen Lehman, MS
Shereen Lehman, MS, is a former writer for Verywell Fit and Reuters Health. She's a healthcare journalist who writes about healthy eating and offers evidence-based advice for regular people.