Antioxidants 102: Free radicals, oxidative stress & inflammation (plus 5 tips for fighting them)

Healthy food clean eating selection: fish, fruit, vegetable, seeds, superfood, cereals, leaf vegetable on gray concrete background copy space

Antioxidants are good for you — this much you know.

You also know there are certain foods you can eat to boost your antioxidant levels, such as squash, citrus, fish and crab.

But do you know how antioxidants do all those good things for your body?

WellTuned spoke with Leslie Cornett, registered dietitian-nutritionist at BlueCross BlueShield of Tennessee, to get specifics.

Quick refresher: What are antioxidants?

Cornett: An antioxidant is a substance that stops or slows cell damage in our bodies. Antioxidants work by neutralizing other substances known as free radicals.

What are free radicals?

Cornett: A free radical is an atom that’s unstable. As a kind of waste product, free radicals are produced by cells in our bodies and in the environment at large.

Stable vs. unstable atoms

Every atom has an outer shell that’s filled with electrons.

  • If every spot in an atom’s outer shell is filled, the atom is stable.
  • If there’s an empty spot in an atom’s outer shell, that atom is unstable.

Antioxidant working principle abstract vector representation, illustration of a process of electron donation to a free radical molecule on a cell as a background, healthcare template

Cornett: When an atom has an unpaired electron, this unstable atom — a free radical — will go looking for another atom to steal an electron from. Naturally, if it succeeds in stealing an electron, it damages the molecule it steals from – unless that molecule is an antioxidant.

Antioxidants and free radicals

Cornett: Antioxidants are compounds that voluntarily give away their electrons. When an antioxidant donates a stabilizing electron, the free radical can no longer cause damage to other cells. By sacrificing their electrons, antioxidants stop damaging processes, which are also known as oxidative stress.

What is oxidative stress?

Cornett: Oxidative stress occurs when the ratio of free radicals to antioxidants is out of balance.

When the unstable atoms in free radicals don’t get neutralized, that causes cellular damage, or oxidative stress, in the form of disease, skin damage, inflammation, etc.

How does oxidative stress get out of control?

Cornett: Free radicals are produced naturally in the body by our metabolism and other cellular processes. Typically, our bodies can fight off the free radicals that are produced.

However, certain lifestyle factors can accelerate the production of free radicals. For example, prolonged or extreme exposure to toxins can throw that balance off and cause damage.

External causes of oxidative stress 

Cornett: Oxidative stress can be caused or worsened by exposure to:

  • Toxins
  • Chemicals (ex. pesticides)
  • Environmental pollutants (ex. air pollution)
  • Smoking
  • Alcohol
  • UV rays
  • Unhealthy foods (ex. fried foods)

Problems connected to oxidative stress 

Cornett: Studies have connected oxidative stress to:

What role does inflammation play?

Cornett: Like oxidative stress, inflammation has been linked to conditions from cancer and heart disease to diabetes. When a part of your body is inflamed, it means your immune system has identified illness or trauma and is working to heal it.

There are two kinds of inflammation:

  1. Acute inflammation is temporary — your wrist swells after you sprain it, or your fingers swell after you eat unhealthy foods for a few days.
  2. Chronic inflammation, on the other hand, is slow and lasts months or years. If you have a condition such as diabetes, heart disease, arthritis, COPD, or allergies, you may experience chronic inflammation that needs to be managed with lifestyle changes, diet, medication, etc.

Oxidative Stress Diagram

How do you fight free radicals and oxidative stress?

Cornett: As always, a healthy lifestyle is the best defense.

To keep your level of oxidative stress low:

  1. Eat an antioxidant-rich diet
  2. Limit alcohol use
  3. Avoid smoking (first- and second-hand)
  4. Avoid unhealthy sun exposure
  5. Take time to rest, recuperate and recover from stress
  6. Get regular physical activity 

            More from Leslie Cornett and WellTuned

Ashley Brantley

Ashley Brantley has been writing about food, culture and health for more than a decade, and has lived in three of Tennessee’s four major cities (Memphis, Nashville and Knoxville).

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