There are tons of buzzwords in the nutrition field, and “antioxidants” is definitely one of them. But what are antioxidants really, and how do they affect your body?
From ketchup to pomegranate juice, plenty of foods are known for containing antioxidants. You’ve probably heard those compounds can do a lot for your health—they’ve been touted as doing everything from preventing heart disease to cancer—but are they as helpful as people say they are?
Like many things in the nutrition field, there’s a lot to unpack regarding antioxidants. And, despite marketing claims singing their praises, they’re not exactly a panacea on your dinner plate. That doesn’t mean you should discount them, though: Antioxidants can bring a bunch of benefits with them.
From how exactly they work to how you should be taking them in (and how much), here’s what you need to know about antioxidants.
What are antioxidants?
Before talking about what an antioxidant is, it helps to understand what we mean by another wellness buzzword: “free radical.” Free radicals refer to any molecule in your body that contains an unpaired electron, which makes them very unstable and keeps them looking for other compounds to bind to. Free radicals can serve some important functions in the body, such as signaling between cells, but because they are so reactive, they can also cause damage to cells through a process called oxidative stress.
Your body generates free radicals during activities like digestion and vigorous exercise, and in response to things like UV light exposure, pollution, smoking, and certain diseases, Chwan-Li (Leslie) Shen, Ph.D., associate dean for research at Texas Tech University Health Sciences, tells SELF. It’s when free radicals are produced in excess that they can become problematic.
Antioxidants, on the other hand, can help keep these free radicals in check. Antioxidants are compounds—either made in your body or consumed from external sources—that help neutralize free radicals and other molecules in your body that can damage cells and tissues, Mahdi Garelnabi, Ph.D., an associate professor of biomedical and nutrition sciences at the University of Massachusetts-Lowell, tells SELF. They do this through a variety of mechanisms, such as by lending an electron to a free radical to make it less reactive or by binding to a substance in a way that prevents further reactions.
By stabilizing these free radicals, antioxidants can also help your immune system function more efficiently and mitigate chronic inflammation, which is thought to be a driving force for many health problems, like cardiovascular disease and cancer. Antioxidants may also, through separate mechanisms, help repair DNA and cell membranes.
Where can you find antioxidants?
Your body makes some antioxidants on its own, but sometimes that’s not enough. “A lot of times, your body generates too many free radicals, and your body cannot handle it, so external antioxidant intake is important,” Dr. Shen says.
There are thousands of antioxidants, and they are not only present in highly hyped “superfoods.” You can find antioxidants in a broad range of foods—like fruits, vegetables, seafood, whole grains, and meats—as well as in supplement form.
Some antioxidants are essential vitamins that your body needs to function, while others are essential minerals. Examples of antioxidant vitamins include vitamin C (found in brussels sprouts, red cabbage, and peppers), vitamin E (found in almonds, sunflower seeds, and olive oil), and vitamin A, which your body makes from beta carotene (found in collard greens, sweet potatoes, and cantaloupe). Examples of antioxidant minerals include selenium (found in Brazil nuts, pork, and turkey) and zinc (found in oysters, beef, and pumpkin seeds).
Then there are antioxidants that aren’t exactly considered essential nutrients, but still have effects on cells and tissues, Bradley Bolling, Ph.D., an assistant professor of food science at the University of Wisconsin-Madison, tells SELF. You can find these in plant, animal, and other dietary sources.
A few examples of these antioxidants include carotenoid cousins of beta carotene such as lycopene (found in watermelon, tomato sauce, and ketchup) and lutein and zeaxanthin (found in spinach, Romaine lettuce, and Swiss chard), chlorogenic acid (found in coffee, apples, and eggplants), flavonoids (found in berries, tea, and citrus fruits), and ergothioneine (found in mushrooms). Many of these non-essential antioxidants are being studied for their potential effects on optimizing health, preventing chronic disease, promoting longevity, and reducing inflammation, says Dr. Bolling. “There are varying grades of evidence for the effectiveness of these non-nutritive antioxidants,” he says.
How does eating antioxidants affect your body?
As a whole, antioxidants can be helpful because they fight back against the aforementioned issue of oxidative stress, which is linked to a wide swath of health problems. Cancer, neurodegenerative diseases, diabetes, and other metabolic diseases are just a few examples, says Dr. Garelnabi.
Of course, a multitude of factors determine your risk of developing various diseases—oxidative stress being just one of them. Research does point to a broad range of health benefits in people who consume more antioxidants, but the National Institutes of Health notes that it’s possible the benefits of antioxidant-rich diets may have to do with a combination of substances in the food—or even other related lifestyle or dietary factors—rather than the antioxidants themselves.
“Eating antioxidant-rich food is not only targeting one disease, but sometimes systemically helping the body to get a balance,” says Dr. Shen.
Let’s take a look at the research showing a link between high antioxidant intake and reduced risk of disease. In one study published in the European Journal of Nutrition, researchers classified 23,595 Americans into four groups based on their antioxidant consumption. People who ate the most antioxidants had a 21% lower risk of dying over a 13-year period than people who ate the least, even as the researchers accounted for relevant mitigating factors such as participants’ age, sex, and economic status. (It’s worth noting, though, that this study was based on a 24-hour dietary recall, or people’s recollections of just one day of eating. Plus, as we mentioned above, the benefits may also have to do with other substances in the food, which can’t be measured here.)
According to a meta-analysis published in Critical Reviews in Oncology/Hematology of 19 previously published studies that included over 700,000 people, a diet high in antioxidants may reduce the risk of cancer, with significant reductions seen with colorectal, endometrial, and gastric in particular. Research also indicates that high amounts of dietary antioxidants may influence your risk of developing type 2 diabetes and stroke.
So getting a good amount of antioxidants in your diet is generally considered to be good for your health. But because different antioxidants can have different effects within the body, it’s worth talking to your health care provider about your specific health history and risk factors, as well as the role that certain antioxidants may have on your health. For instance, higher intake of flavonoids has long been linked with a reduced risk of heart disease, and a recent study in the American Journal of Clinical Nutrition suggests an association with a reduced risk of Alzheimer’s disease too. If you’re concerned about a particular condition, talk to your health care provider about whether you should focus on eating more of any one particular thing—especially if you feel like your diet is unbalanced in any way.
All that said, dietary antioxidants are no substitute for medical treatment, and getting a balanced diet is always more beneficial than relying on any one nutrient. It’s worth noting that much of the research we’ve covered so far looked at total antioxidant intake, and what researchers found were correlations—not cause-and-effect relationships. While there’s plenty of research pointing to a link between higher antioxidant intake and lower risk of disease, we can’t say with certainty that loading up on any one antioxidant will change your health in specific ways. It’s about balance and variety, which we’ll explain in a bit.
How should you work antioxidants into your diet?
For the antioxidants that fall into the essential nutrient category, recommended daily allowances (RDAs) exist to help you plan your intake. For selenium, the RDA is 55 micrograms per day. For zinc and vitamins A, C, and E, you can find RDAs for your age and sex in the Dietary Guidelines for Americans. (For instance, women 31–50 should shoot for 8 mg of zinc, 700 micrograms of vitamin A, 15 mg of vitamin E, and 75 mg of vitamin C.) Some of these essential nutrients, like vitamin C and vitamin A, are listed on food labels, so it’s easy to tally up how much you’re getting.
There’s no standard recommended amount to consume for the antioxidants that aren’t essential nutrients; researchers are still determining them, says Dr. Bolling. You won’t see the dose of those antioxidants listed on the label of foods containing them, either.
So rather than trying to hit a specific amount of these, you can instead look to add more foods that contain antioxidants into your diet. “Just having berries for breakfast or eating citrus or drinking green tea is enough to put people into the higher level of patterns of consumption,” says Dr. Bolling.
The best way to enrich your diet with antioxidants is to eat plenty of fruits and vegetables (the U.S. Dietary Guidelines recommend two and a half cups of vegetables and two cups of fruits per day), says Dr. Garelnabi. Nuts, whole grains, dark chocolate, and tea are also good antioxidant sources, as are lean meats and seafood, says Dr. Shen.
Diversity is also important in your diet, since some antioxidants work better together, says Dr. Garelnabi. To make sure you’re getting a variety, try to include different colors on your plate, since the color of fruits and vegetables can serve as a clue to their antioxidant content, suggests a study published in Current Research in Food Science. For example, reddish foods like apples, strawberries, sour cherries, red cabbage, and red peppers tend to be rich in a type of flavonoid called anthocyanins, while orange and yellow produce like mangos, yellow peppers, oranges, bananas, and nectarines are good sources of vitamin C.
So what about supplements? Loading up on antioxidants in the form of supplements doesn’t actually bring you any greater benefits. In fact, a 2014 review of the research stated “there is no evidence to support the use of antioxidant supplements in the primary prevention of chronic diseases or mortality.” In fact, there is some evidence that they may even be harmful, especially in high doses.
Eating a balanced diet for most people means you’re likely getting enough antioxidants and don’t need to take antioxidant supplements, says Dr. Garelnabi. However, some people may benefit from adding supplements, especially if they can’t tolerate or need to avoid certain foods. Just talk with your doctor before taking any supplements to determine whether you really need them and whether they could interact with any medications you take.
Otherwise, if you’re focusing on a variety in your diet, and are making it a point to try new fruits or veggies to broaden what you’re taking in, you’re likely doing just fine on the antioxidant front. To really sharpen those benefits, though, you may want to pair your balanced plate with a workout routine: Exercise—as long as you aren’t overtraining—may even help boost your body’s production of natural antioxidants, says Dr. Garelnabi.