What are Antioxidants and What Do They Do?

Quick Health Scoop

• Antioxidants are substances that may neutralize free radicals in the body
• Free radicals in the body can have an impact on cells
• Some antioxidants are Vitamins A, C and E and carotenoids, which include beta-carotene, lycopene and lutein
• A diet rich in antioxidant foods—especially fruits and vegetables—can help minimize this impact

By now, you may have read the hype about antioxidants and you know they’re good for you. You may also know that “free radicals” are somehow involved. But sometimes it feels like you need a college degree in science or nutrition to understand the complexities of it all. What are antioxidants? What do antioxidants do and how do they benefit your health? And what foods contain antioxidants?

Let’s break it all down for you.

What Are Antioxidants?

In a nutshell, the term antioxidant means substances that may effect some cells. These substances can occur naturally in your bodyor be man-made. So, what do antioxidants do? They help to neutralize free radicals caused by oxygen (known as oxidative damage). Among the many things that can cause oxidative damage are free radicals. But exactly what are free radicals?

What Are Free Radicals In The Body?

To understand what a free radical is, you need to know that many internal body processes occur (such as converting food into energy) and they require oxygen. The byproducts of using oxygen are called oxidants (often called “free radicals”), which are very unstable molecules. What do free radicals do? On the positive side, they do play an important role in many normal cellular processes. But at high concentrations, free radicals may have an impact on cells, including DNA, proteins, and cell membranes.¹ (For a more tangible comparison, think of how oxidants can cause rust on a car.) Free radicals can cause oxidative stress. 

Note that free radicals are also formed in our body from exposure to the environment such as from air pollution, cigarette smoke, and even ultraviolet light from the sun.

What are the benefits of antioxidants? Well, remember how antioxidants help neutralize free radicals caused by oxygen? They do this by “neutralizing) free radicals. How? Antioxidants bind to oxidants, blocking the impact from occurring in the first place. They’re like superheroes!

Learn More: A Guide to Herbal Supplements

What Vitamins and Other Nutrients Are Antioxidants?

Now that you’ve got a clearer picture of the power of antioxidants, you might be wondering more specifically what vitamins are antioxidants? Helping to support healthy cells from free radical, the antioxidants list include Vitamins A, C, and E, and carotenoids, which include beta-carotene, lycopene and lutein. They’re found abundantly in fruits and vegetables. If you’re looking for extra antioxidant support, consider taking a herbal supplement like a turmeric curcumin supplement.

Learn More: Turmeric's Antioxidant Benefits

What Are Carotenoids?

With roughly 600 carotenoids in foods, the antioxidant powerhouses include beta-carotene, lycopene, lutein, and zeaxanthin. 

• Beta-carotene: As an important nutrient, beta-carotene is known as provitamin A (which means your body uses it to make Vitamin A) and it’s only found in plants. (Vitamin A from animal sources is called preformed Vitamin A.) Beta-carotene works together with Vitamin A to support the reproductive system and maintain healthy skin, eyes, and immune system.⁴
• Lutein: Related to beta-carotene and Vitamin A, Lutein is a carotenoid and this key nutrient helps support eye function and healthy vision.⁵
• Lycopene: This naturally occurring carotenoid gives fruits and vegetables a reddish color.⁶ 
• Selenium: As a key mineral, selenium plays an important role in reproduction, thyroid gland function, and DNA production.⁷ 
• Vitamin A: This fat-soluble vitamin plays an important role in supporting your immune system, vision, reproduction, and cell function. Vitamin A also helps support the functioning of the heart, lungs, kidneys, and other organs.⁸
• Vitamin C: As one of the most powerful antioxidants, Vitamin C helps support a healthy immune system. This water-soluble vitamin also plays an important role in making collagen, a protein required to help support skin structure, , and helps with the absorption of iron from plant-based foods.⁹
• Vitamin E: Vitamin E is a fat-soluble vitamin that plays an important role as an antioxidant and can help support  the immune system. This essential nutrient also helps support healthy blood vessels as well as support cell health.¹⁰

Learn More: How Much Vitamin C Should You Take Per Day?

What Foods Are High In Antioxidants?

When it comes to foods that are high in antioxidants, the shining nutrient stars below top the list. 

Beta-carotene-Rich Foods: Green leafy vegetables (spinach, collards, kale), orange fruits and vegetables (sweet potatoes, carrots, pumpkin, butternut squash, apricots, cantaloupe, oranges).

Lutein-Rich Foods: Egg yolks, broccoli, spinach, kale, corn, orange pepper, kiwi fruit, grapes, orange juice, zucchini, squash.⁵

Lycopene-Rich Foods: Tomatoes, watermelons, red oranges, pink grapefruits, apricots, rosehips, and guavas.⁶

Selenium-Rich Foods: Brazil nuts, fish, shellfish, beef, poultry, barley, brown rice.¹¹ 

Vitamin A-Rich Foods: Beef liver and organ meats, some fish (herring), green leafy vegetables (spinach, collards, kale), orange fruits and vegetables (sweet potatoes, carrots, pumpkin, butternut squash, apricots, cantaloupe, oranges), dairy products, fortified breakfast cereals.⁸ 

Vitamin C-Rich Foods: Citrus fruits (oranges, grapefruits, tangerines), strawberries, sweet red peppers, tomatoes, broccoli, potatoes.⁹

Vitamin E-Rich Foods: Apricots, vegetable oils, wheat germ, whole-grains, fortified cereals, seeds (sunflower), nuts (almonds, hazelnuts, peanuts) and nut butter.³

Aim for a total of 5–9 servings of these foods every day.²

Learn More: The Best Healthy Foods to Eat

The Bottom Line

So, what are antioxidants good for? They help support you from the effects of free radicals. Eating foods that are high in antioxidants means including plenty of fruits and vegetables in your daily meals and snacks. If you don’t eat a balanced, healthy diet, you might consider taking antioxidant supplements such as Vitamin C, or Vitamin E.^† Talk with your doctor before using supplements. 

Continue to check back on the Nature Made blog for the latest science-backed articles to help you take ownership of your health.

Learn More About Antioxidants & Your Health:

• Milk Thistle Benefits
• Elderberry Health Benefits
• Heart Healthy Foods List

This information is only for educational purposes and is not medical advice or intended as a recommendation of any specific products. Consult your health care provider for more information.

References 

1. National Cancer Institute. “Antioxidants and Cancer Prevention.” February 6, 2017. Accessed on: April 21, 2021. https://www.cancer.gov/about-cancer/causes-prevention/risk/diet/antioxidants-fact-sheet 
2. National Center for Complementary and Integrative Health. “Antioxidants: In Depth.” November 2013. Accessed on: April 21, 2021. https://www.nccih.nih.gov/health/antioxidants-in-depth 
3. Academy of Nutrition and Dietetics. “Antioxidants - Protecting Healthy Cells.” March 25, 2021. Accessed on: April 21, 2021. https://www.eatright.org/food/vitamins-and-supplements/types-of-vitamins-and-nutrients/antioxidants-protecting-healthy-cells 
4. University of Rochester Medical Center. “Beta-Carotene.” 2021. Accessed on: April 21, 2021. https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=19&contentid=betacarotene 
5. Medline Plus. “Lutein.” March 24, 2021. Accessed on: April 21, 2021. https://medlineplus.gov/druginfo/natural/554.html 
6. Medline Plus. “Lycopene.” March 25, 2020. Accessed on: April 21, 2021. https://medlineplus.gov/druginfo/natural/554.html 
7. National Institutes of Health. “Selenium: Fact Sheet for Consumers.” March 22, 2021. Accessed on: April 21, 2021. https://ods.od.nih.gov/factsheets/Selenium-Consumer/ 
8. National Institutes of Health. “Vitamin A: Fact Sheet for Consumers.” January 14, 2021. Accessed on: April 21, 2021.  https://ods.od.nih.gov/factsheets/VitaminA-Consumer/ 
9. National Institutes of Health. “Vitamin C: Fact Sheet for Consumers.” March 22, 2021. Accessed on: April 21, 2021. https://ods.od.nih.gov/factsheets/VitaminC-Consumer/
10. National Institutes of Health. “Vitamin E: Fact Sheet for Consumers.” March 22, 2021. Accessed on: April 21, 2021. https://ods.od.nih.gov/factsheets/VitaminE-Consumer/ 
11. Cleveland Clinic. “Antioxidants & Heart Health.” April 22, 2019. Accessed on: April 21, 2021. https://my.clevelandclinic.org/health/articles/16739-antioxidants--heart-health 
12. Harvard T.H. Chan School of Public Health. “Selenium.” 2021. Accessed on: April 21, 2021.  https://www.hsph.harvard.edu/nutritionsource/selenium/ 

Additional Nutrition Data from:

USDA FoodData Central: https://fdc.nal.usda.gov/fdc-app.html#/food-details/1103276/nutrients 

US FDA: https://www.fda.gov/food/food-labeling-nutrition/nutrition-information-raw-fruits-vegetables-and-fish