July 18, 2022

Why You Should Care About Free Radicals

When free radicals don’t have antioxidants to keep them in check, they go rogue

An older person holds both hands out in front of them and squeezes each one as if to relieve tension.

Our bodies are run by a system of incredibly complex processes that keep each other in balance. At the microscopic level, your health is, in part, a result of a carefully choreographed dance between your molecules.


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When the steps are followed precisely, molecules work in concert to help keep you healthy. Like a line dance gone awry, though, if one molecule slides to the left while the other slides to the right, crashes are inevitable.

Enter free radicals, the molecules with the potential to crash your party, if left to their own devices.

You’ve probably heard of free radicals. They’re often connected with aging skin, cancer, Alzheimer’s disease and more, but what are they, really? And how can they be stopped?

We talked with registered dietitian Anthony DiMarino, RD, for an easy-to-follow explanation of free radicals and what you can do about them.

What are free radicals?

Essentially, free radicals are unstable molecules looking for a dance partner.

Molecules are, in part, made up of electrons. Those electrons usually come in even numbers. But free radicals have an odd number of electrons. And they’re not happy about it.

“Free radicals are missing an electron from their outer shell. That makes them unstable, so they go and steal an electron from the molecules in your skin cells, or from your blood cells or from wherever they can. That causes damage to surrounding cells,” DiMarino explains.

Thinking back to the dance, free radicals are the belligerent friend who’ll grab anyone in arm’s reach to do-si-do.

Antioxidants are also unstable and looking for a partner. Like free radicals, antioxidants have an uneven number of electrons. Unlike free radicals, though, antioxidants don’t typically steal from otherwise stable molecules to keep themselves in check.

But antioxidants do happily take an unpaired electron from a free radical. That makes both molecules even-steven.


In the absence of antioxidants, free radicals will tango with just about anyone. And they step on some toes in the process.

Free radicals create oxidative stress

If you don’t have enough antioxidants to keep free radicals in check, they go rogue and steal electrons from wherever they can get them. When you have too many free radicals gobbling up electrons from stable molecules, it’s called oxidative stress. When that happens, cells get damaged and even die.

“When free radicals build up and start stealing electrons, those molecules, in turn, become unstable,” DiMarino says. “That leads to cellular damage down to the DNA level. So, when your body is experiencing oxidative stress in a particular area, we find signs of aging and disease.”

Oxidative stress is like that out-of-control mosh pit that’s forming on the side of the stage. And free radicals are the ones throwing elbows at you.

Health effects of oxidative stress

Studies have connected oxidative stress as a result of a buildup of free radicals to a number of diseases and signs of aging.

“The instability that free radicals cause creates damage right down to the DNA level,” DiMarino explains. “The cells become damaged, and negative effects manifest themselves. So, if you’re out in the sun too much, you can get oxidative stress in your skin, and that can lead to sun spots or even skin cancer. High blood sugar can cause oxidative stress on the blood vessels, which can lead to heart disease and poor circulation, for example.”

A short list of diseases that have been connected to free radical damage includes:

What causes free radicals?

Research explains that free radicals are naturally occurring molecules that are both created by our bodies and that enter our bodies from our environment.

Sources of free radicals in our environment include:

  • Cigarette smoke.
  • Environmental pollutants.
  • Certain drugs and pesticides.
  • Industrial solvents.
  • Ozone.
  • Ultraviolet radiation (aka direct sunlight and tanning beds).

Your body also produces free radicals naturally, including in response to stress and inflammation. Studies show oxidative stress can also occur after an extreme intensity workout.


How to reduce free radicals

The fact is that you can’t completely avoid free radicals. You can, however, limit your exposure to some unnecessary free radicals.

There are two ways to keep free radicals from taking over your dance floor. One is to limit how many of them you let in. The other is to take in enough antioxidants to keep the free radicals from taking center stage.

Limit your exposure to free radicals

Researchers suggest a few ways you can protect yourself from an abundance of free radicals:

  • Don’t smoke.
  • Limit your alcohol intake.
  • Limit your time in the sun (and properly use sunscreen).
  • Manage your stress.
  • Avoid pollution, to the extent you can.

Fight free radicals with antioxidants

Antioxidants are the key to keeping free radicals from doing the two-step with your healthy cells. Your body naturally creates some antioxidants, but DiMarino says an antioxidant-rich diet can help as well.

Getting your antioxidant fix from your diet has been proven to help minimize your risk of oxidative stress and damage. Try these vitamin-rich foods that are high in antioxidants:

  • Vitamin C: Broccoli, Brussels sprouts, blueberries, cauliflower, cantaloupe, grapefruit, leafy greens, kale, strawberries, sweet potatoes, bell peppers, tomatoes and citrus fruits.
  • Vitamin E: Almonds, avocado, sunflower seeds, oatmeal and legumes (beans, lentils, split peas), peanuts, red pepper and leafy greens.
  • Beta carotene: Apricots, cantaloupe, mangos, carrots, grapefruit and bell peppers, asparagus, beets, kale, mangoes, orange, peaches, pink grapefruit, pumpkin, squash, sweet potatoes, tomatoes, tangerines and watermelon.
  • Selenium: Eggs, tuna, salmon, brown rice, onions, poultry, shellfish and beef — limited to no more than one to two servings per week.
  • Zinc: Beef, poultry, oysters, shrimp, sesame seeds, pumpkin seeds, chickpeas, lentils, cashews and fortified cereals.
  • Phenolic compounds: Apples, wine (in moderation), onions, tea, cocoa, berries, grapes, peanuts and some spices, including oregano, thyme and rosemary.

Remember that, just like free radicals, antioxidants are unstable molecules, so an overabundance of antioxidants can potentially be damaging. DiMarino says over-supplementing with antioxidants can be problematic, so stick with getting your antioxidant fill from healthy foods before considering supplements.

“Food-first is always the best way to go in terms of getting proper nutrition,” DiMarino says. “If you think you aren’t getting enough antioxidants from the foods you eat, talk with your doctor about whether a supplement could help.”

Bottom line: Free radicals are like the Whitney Houston song — they just wanna dance with somebody. Shut them out as best you can by following a healthy lifestyle. As for the rest, a diet rich in antioxidants can help keep your biochemical music bumpin’.

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