What Are Antioxidants?
Antioxidants are substances that protect your body from the effects of unstable molecules called free radicals. Free radicals develop when atoms in your body gain or lose charged particles called electrons.
Free radicals aren’t all bad. They play an important role in many biological processes including cell division. They also help cells talk to each other, and they help your body defend against infection.
But when too many free radicals build up in the body, they can do serious damage to cells. This may contribute to conditions like cancer, heart disease, high blood pressure, and diabetes.
Antioxidants are found naturally in many fruits and vegetables and other foods, and can also be taken as supplements. They're in some skin-care products, too.
Types of Antioxidants
People tend to talk about antioxidants as a broad category, but they’re actually more of a big family. Vitamin C is an antioxidant, and so are vitamin E, vitamin A, and beta-carotene. There are many more, each with their own benefits.
Other antioxidants include:
- Coenzyme Q10
- Lipoic acid
Because antioxidants have the power to protect you from free radicals, they may be able to lower your odds of some diseases. But the connection isn't always clear, especially when it comes to supplements.
Still, a diet high in fruits and vegetables is healthy for many other reasons. Foods with antioxidants are typically:
- High in fiber
- Low in saturated fat and cholesterol
- Full of vitamins and minerals
Antioxidants for cancer prevention
Some research suggests that antioxidants could prevent some of the damage free radicals cause that can lead to cancer. But there's no scientific evidence that antioxidant supplements work to prevent cancer. We need more research to determine whether antioxidants from foods can help to reduce your cancer risk.
Antioxidants for eyes
Age-related macular degeneration, or AMD, is the most common cause of permanent vision loss in adults over age 50. It happens when the macula, which is deep in the back of your eye, begins to wear away. In time, it can lead to loss of your central vision field.
Antioxidants may help to lower your chances of AMD by up to 25%. If you already have AMD, they can help you keep more of your vision.
Vitamins C and E can lower the chance of cataracts. These are protein buildups that cloud the lens at the front of the eye, ultimately causing blurry vision. Antioxidants may also slow the progression of cataracts, letting people maintain better vision longer.
Antioxidants for heart health
There’s a lot of debate about whether antioxidants help lower people’s chances of heart disease. On one hand, research has shown that people who eat more fruits and vegetables have lower risks of heart disease and stroke. Early research has shown that antioxidants may be responsible for this benefit.
On the other hand, follow-up studies of antioxidant supplements have failed to show the same benefits. Some scientists believe that this has to do with the higher levels of antioxidants in supplements.
Getting antioxidants from foods may be the secret, but more research is needed to find out if there’s a real connection.
Antioxidants for skin
We need more research, but there's some evidence that the antioxidant vitamins C and E have skin benefits. Studies have shown that a vitamin C formula applied to the skin might help:
- Improve the appearance of wrinkles
- Protect skin from ultraviolet ray (UV) damage from the sun when used along with broad-spectrum sunscreen
- Make dark spots on the skin less visible
As an ingredient in moisturizer, vitamin E appears to help:
- Make skin softer
- Reduce moisture loss
- Protect skin cells from sun damage
An antioxidant-rich diet, with plenty of fruits, veggies, nuts, whole grains, and fatty fish, also promotes healthy skin.
Different foods contain different antioxidant vitamins and minerals.
The antioxidant beta-carotene is common in orange foods like:
- Sweet potatoes
Some green leafy vegetables also contain high levels of beta-carotene, including:
- Collard greens
These vegetables also contain high levels of the antioxidant lutein.
The antioxidant lycopene is in fruits and vegetables with pink and red or red-orange flesh. Examples include:
- Pink grapefruit
Approximately 85% of lycopene in most American diets comes from tomatoes and tomato-derived foods.
The antioxidant vitamin A comes in three different forms, the best-known being retinol (vitamin A1). You’ll find high levels of vitamin A in foods like:
- Sweet potatoes
- Egg yolks
The antioxidant vitamin C is found in high levels in many fruits and vegetables as well as in:
- Some cereals
The antioxidant vitamin E is plentiful in almonds. You can also find it in:
- Various oils including corn, soybean, and safflower
Plant-based foods tend to be much higher in antioxidants than meats. Berries and berry products rank near the top of the antioxidant scale, including:
- Wild strawberries
Many herbs and spices are high on the list, too.
Other Foods High in Antioxidants
Fruits and veggies aren't the only foods that add antioxidants to your diet. You can find them in nuts, coffee, and even chocolate.
Antioxidants in coffee
Coffee beans contain a number of antioxidants, including:
The American Chemical Society says that coffee is the No. 1 source of antioxidants in the typical U.S. diet. On the basis of antioxidants per serving size and frequency of consumption, coffee beat out all of the other foods studied.
Antioxidants in dark chocolate
Dark chocolate comes from the seeds of cacao pods, which are roasted into cocoa beans. Cocoa is a source of antioxidants because it contains flavanols, which may help protect the heart. Dark chocolate contains more antioxidants than milk chocolate and white chocolate because it has a higher concentration of cocoa solids and less cocoa butter, milk, sugar, and oil.
Antioxidants in red wine
Red wine contains the antioxidant resveratrol, which comes from the skin of red grapes. It's also found in peanuts and berries. Evidence suggests that resveratrol could destroy cancer cells and increase the effectiveness of cancer treatments, although the findings aren't conclusive.
Antioxidants in nuts
Nuts are a rich source of antioxidants. Walnuts, pecans, and chestnuts have the highest amount of antioxidants of all tree nuts. Although they're technically legumes, peanuts are also high in antioxidants.
Supplements might seem like an easy way to get antioxidants. But no supplement can match the health effects of a varied, healthy diet that includes plenty of colorful fruits and vegetables.
- The FDA doesn't regulate dietary supplements. So you can't be sure whether a supplement is effective, safe, or actually contains what it claims to.
- Antioxidant supplements haven't been shown to protect against or treat disease, other than specific formulas made for people with macular degeneration.
- Supplements may not be balanced. For example, eight different forms of vitamin E are found in foods. But supplements usually contain just one form of the vitamin.
- Antioxidants in high doses could be harmful.
While a supplement can help if you're deficient in a certain nutrient, supplements can't make up for an unbalanced diet. Always tell your doctor before taking one, especially if you're pregnant, nursing, or taking medication.
While antioxidants have loads of potential health benefits, there are a few things to keep in mind about them, particularly if you get yours through supplements.
Antioxidant supplements could interact with medicines that you're taking for another condition. For example, if you take a blood thinner, vitamin E supplements could boost your chances of bleeding.
If you smoke and you take high doses of beta-carotene, your chances of lung cancer go up. If you take a lot of vitamin E, you have a higher chance of prostate cancer and stroke.
Talk with your doctor about all the medications and supplements you take. They'll help you make sure that what you take will be safe for you.