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Understanding Antioxidants

These compounds may help protect our cells from disease-causing damage
Written by 
Meghan Rabbitt
Canyon Ranch Reviewer: 
Updated on: 
June 26, 2015

While the message about the importance of dietary antioxidants has come through loud and clear (and may be what has already made foods like berries and kale regular entries on your grocery shopping list), there remains much confusion about how, exactly, they work in the body, and how best to get them. One important and often misunderstood point? Antioxidants are best obtained from foods rather than supplements.

In a nutshell, “antioxidant” is a catchall term for different types of compounds found in foods and produced by our bodies that may protect our cells from damage. This damage is caused by molecules called free radicals, which can be harmful in excess.

Our bodies produce free radicals every second of every day as a result of turning food into a useable form of energy, known as ATP, or adenosine triphosphate. “Think of your body burning food for fuel like burning gas in your car’s cylinder,” says Mark Liponis, M.D., Chief Medical Officer of Canyon Ranch. “The ‘sparks’ that fly off the fire are dangerous free radicals.”

Free radicals can be dangerous: They have an odd number of electrons, and when they bounce around your cells, they rob electrons from healthy cells, to neutralize their own charge. “This can cause a lot of damage on the cellular level,” Dr. Liponis says.  This harmful cascade, known as oxidative stress, can trigger a number of health issues including inflammatory diseases (such as arthritis), heart disease, stroke, Alzheimer’s and certain cancers. Oxidative stress is also involved in the process of aging.

The good news? “Our bodies know how dangerous these free radicals are,” Dr. Liponis says. The natural antioxidants that our bodies produce, as well as those we consume, interact with free radicals to neutralize their danger. Reducing our production of harmful free radicals is a worthwhile strategy for health and longevity.

Why Food Is Best

While you might be tempted to buy supplements to boost your antioxidant intake, it’s wise to be cautious. There’s not enough evidence proving antioxidant supplements work to prevent disease, and some studies show that synthetic antioxidants (particularly when consumed in high doses) may actually cause the oxidative stress you’re trying to avoid; once an antioxidant does its job, it actually becomes an oxidant, albeit a bit weaker one. Furthermore, new research hints that the kind of free radicals created as a byproduct of exercise may actually have a beneficial if not critical role in helping you build muscle and improve the efficiency and fitness of your musculoskeletal system. So, “taking a lot of antioxidants to nullify or neutralize the effect of free radicals may actually hamper the training benefits of being active,” says Dr. Liponis.

We’re now learning that neutralizing all free radicals should not necessarily be our goal, as free radicals may be a critical trigger for building muscle and aerobic fitness. It’s possible to get too many antioxidants, especially via supplementation, but not so much by eating, which is why we recommend turning to whole foods to get the dietary antioxidants your body needs. Furthermore, fruits, vegetables and other good-for-you selections are packed with several nutrients, which is the key to their power: “When consumed through a healthy diet, antioxidants work in concert with one another—something you miss out on when just taking, say, a beta carotene supplement—and that’s what seems to produce the beneficial effects,” says Dr. Liponis.

As you choose what to fill your plate with:

  • Make Your Calories Count

Because burning calories produces free radicals, you might assume that eating less is a good strategy. Of course there’s a limit to that strategy, since we can’t eat so little that we become malnourished.

A better route? Reach your daily calorie goals, but choose to do so by eating foods that have a lot of nutrients, Dr. Liponis advises. When it comes to foods with a good nutrient-to-calorie ratio (NCR), think fiber- and water-rich vegetables and fruits, lean meat, fish, poultry and eggs. Nuts and seeds are medium NCR foods, which makes them good choices in moderation. In addition to helping keep your free radical count low, these foods will also fill you up and help you maintain a healthy weight. Low NCR foods to avoid include refined grains and sugary snacks and drinks.

  • Eat the Rainbow

There’s a surprisingly simple way to figure out how antioxidant-rich your diet is: The more colorful your plate, the better off you are. “It’s the pigments in food that actually have the antioxidant properties, and the colors work together,” says Liponis. So for example, carotene works with lutein, which works with xanthine, etc.

He explains: “Neutralizing harmful free radicals is like a game of hot potato. Each antioxidant grabs a free radical, cools it off and hands it off to another antioxidant, each time making the free radical ‘cooler’ and less dangerous, until it can ultimately be excreted by the body.” Colorful foods also almost always have a high NCR, so they’ll also produce fewer free radicals than more calorie-dense foods when you eat them. High NCR foods are also likely to contain vitamins C, E and beta-carotene and the mineral selenium, which are also antioxidants. Our article, Eating a Colorful Diet for Cancer Prevention, offers more benefits and advice.

Remember to Keep Moving

Exercise actually generates more free radicals in the body, since you turn food into ATP in order to get the energy to move. But this doesn’t mean you shouldn’t be active—quite the opposite. Remember, these free radicals may actually improve your conditioning. And as you work out, your body makes antioxidants to counter the production of these harmful substances. In fact, because exercise creates such an onslaught of free radicals—even more than when we digest food—exercising actually tricks the body into making extra antioxidants. “Exercise seems to be one of the strongest ways to get your body to produce its own antioxidants,” Dr. Liponis points out. It’s important to make your exercise regular, since it takes time for the body to adapt to physical activity with extra antioxidant production.

National Cancer Institute
National Institute on Aging
Pharmacognocy Review (July–December 2010)
Rice University
About the author 
Meghan Rabbitt is an editor and writer whose work has been published in Women’s Health, Fitness, Shape, Runner’s World, Prevention, Parents and Weight Watchers.