Although it's a slow process, careful, objective medical studies provide the guidance that counts. In most cases, scientific investigations of supplements start with simple observational studies, in which researchers compare the health status of folks who take a particular supplement with the health of people who don't take the supplement.

It's an important effort, but the results don't always hold up. So the next step is to conduct randomized clinical trials, in which volunteers are assigned by lot to take either the supplement or an identical-looking placebo "dummy pill" while researchers track their health.

In the best studies, neither the volunteers nor the researchers know who is getting the real thing until the code is broken at the end of the trial. Everyone wants to know if supplements can help. It's a good question. Here's where we stand today — but you should keep an eye out for new results, since recommendations will change as scientific studies trickle in.

Unfortunately, in most cases, the studies have failed to confirm our hopes, though there are exceptions.

Many people take supplements in the belief that they will preserve health or ward off illness; many others use supplements in an attempt to treat specific conditions that have already developed. We'll have a look at popular supplements in both categories, starting with preventive supplements used principally by healthy people.

Vitamin D. To get vitamin D the old-fashioned way, by producing it in the skin, we need lots of sunshine. But as work has shifted from the farm to the office and as we've learned to use sunscreens to reduce the risk of skin cancer and wrinkles, many people lack sufficient amounts of the "sunshine vitamin.

Vitamin D is needed to absorb calcium from the intestines; that's why vitamin D is so important for healthy bones. Current guidelines call for IU international units a day below age 71 and IU a day thereafter. But many experts recommend to 1, IU a day for most adults; daily doses up to 4, IU are considered safe, but more can be toxic.

It's very hard to get the vitamin D you need from your diet; oily fish and fortified dairy products are the only important sources. So supplements do make good sense for most adults. The form known as vitamin D 3 is usually recommended, but D 2 is also effective; for best results, take your vitamin D along with a meal that has some fat.

If you want to be sure you need this supplement, ask for a blood test; levels of at least 30 nanograms per milliliter are considered best. Vitamin E, vitamin A, beta carotene, and vitamin C were the favorites of the s and early '90s.

But many careful randomized clinical trials have not shown any benefit against heart disease, cancer, or other illnesses. And that's not the worst of it. In fact, even moderately high doses of vitamin A increase the risk of hip fractures, and high levels of vitamin A have been linked to an increased risk of prostate cancer; beta carotene increases lung cancer risk in smokers; and vitamin E increases the risk of prostate cancer and has been linked to an increase in respiratory infections, heart failure, and the overall death rate.

Do not take antioxidant supplements. One exception: people with moderate or advanced age-related macular degeneration AMD benefit from special antioxidant supplements that also contain zinc. Unfortunately, though, this preparation does nothing to prevent AMD in people who have healthy eyes.

Vitamin B 12 is found only in animal-based foods, so strict vegetarians may need supplements. In addition, many older people don't make enough of the stomach acid that's needed to liberate B 12 from animal products so it can be absorbed. But B 12 is also added to fortified grain products and other foods, and this synthetic B 12 is easy to absorb even without stomach acid.

That means a single bowl of cereal can provide your RDA of 2. Still, if your fortified grain consumption is erratic, a B 12 supplement is reasonable. Folate is more complex.

The vitamin is essential for the production of red blood cells, and it has an important role in DNA production and in repairing defects in the genetic code. Although folate is present in a variety of leafy green vegetables, fruits, legumes, and meats, until the late s, many Americans didn't get their RDA of mcg from foods — and folate deficiencies during pregnancy sharply increase the risk of devastating birth defects.

That's why the U. and Canadian governments issued regulations mandating folic acid fortification of all grain products including cereal, bread, flour, pasta, and rice from onward.

Folate fortification has eased the birth defect problem, but obstetricians still recommend supplements for women who are trying to conceive or who are already pregnant. Despite their iconic status, there is no evidence that multivitamins enhance health and well-being or prevent illness.

Many foods that provide these nutrients also supply antioxidants called lutein and zeaxanthin, nicknamed the eye vitamins , found in brightly colored foods like fruits and vegetables — especially leafy greens and types that are deep orange or yellow.

These antioxidants are believed to be easily transported around the body, especially to the delicate parts of the eyes called the macula and the lens. In fact, there are more than different types of carotenoids found in nature, but only about 20 make their way into the eyes.

Of those 20, lutein and zeaxanthin are the only two macular carotenoids that are deposited in high quantities into the macular portion of the eyes, which is one of the earliest to be damaged during aging.

Research shows that high-lutein sources like spinach are proven to help decrease eye-related degeneration and improve visual acuity. Similarly, flavonoid antioxidants found in berries, such as bilberries or grapes also great sources of the antioxidant resveratrol , may be especially beneficial at supporting vision into older age.

Perhaps most noticeably, free radicals speed up the aging process when it comes to the appearance and health of your skin. Using antioxidants for skin may help combat this damage, especially from eating sources high in vitamin C, beta-carotene and other antioxidants.

Vitamin A and C have been connected to a decrease in the appearance of wrinkles and skin dryness. Vitamin C, specifically, is a powerful antioxidant that can help reduce the effect of oxidative damage caused by pollution, stress or poor diet.

Vitamin A deficiency has also been linked to skin dryness, scaling and follicular thickening of the skin. Similarly to how free radicals damage surface skin cells, keratinization of the skin, when the epithelial cells lose their moisture and become hard and dry, can occur in the mucous membranes of the respiratory, gastrointestinal tract and urinary tract.

At this point, the data does not show that all antioxidants are effective in protecting against heart disease, but some, such as vitamin C, do seem to be. The American Journal of Clinical Nutrition featured a study that found those with high levels of vitamin C in their blood had almost a 50 percent decreased risk of stroke.

Countless studies also have found that people who consume highly plant-based diets — loaded with things like fresh veggies, herbs, spices and fruit — have a better chance of living longer and healthier lives with less heart disease.

Some research has unearthed a potential connection between antioxidants and cancer. In fact, studies have found that high intakes of vitamin A, vitamin C and other antioxidant foods could help prevent or treat several forms of cancer thanks to their ability to control malignant cells in the body and cause cell cycle arrest and apoptosis destruction of cancer cells.

Retinoic acid, derived from vitamin A, is one chemical that plays important roles in cell development and differentiation, as well as cancer treatment.

Lung, prostate, breast, ovarian, bladder, oral and skin cancers have been demonstrated to be suppressed by retinoic acid. Another study collected numerous references demonstrating the findings of retinoic acid in protection against melanoma, hepatoma, lung cancer, breast cancer and prostate cancer.

Many studies have found that people eating plant-based diets high in antioxidants, such as the Mediterranean diet , have better protection over cognition. In addition to improving heart health and cognitive function, some research suggests that antioxidants could aid in the prevention of type 2 diabetes.

For example, one animal model out of Japan showed that administering antioxidants to mice helped preserve the function of beta cells in the pancreas, which are responsible for the production of insulin. Another large review of 12 studies found that vitamin E helped reduce blood sugar levels, while vitamin C was effective at decreasing levels of oxidative stress.

Antioxidants may be easier to add to your diet than you might think. Based on ORAC scores provided by Superfoodly based on research from a broad number of sources , below are some of the top antioxidant foods by weight:. The ORAC scores above are based on weight.

This means that it might not be practical to eat high amounts of all of these antioxidant foods. Other high-antioxidant foods not listed above, which are still great sources and highly beneficial, include common foods like:.

Try to consume at least three to four servings daily of these antioxidant-rich foods even more is better for optimal health.

Along with antioxidant foods, certain herbs, spices and essential oils derived from nutrient-dense plants are extremely high in healing antioxidant compounds. Here is another list of the herbs you can try adding to your diet for increased protection against disease.

Look for percent pure therapeutic grade oils, which are highest in antioxidants:. Other antioxidant-rich herbs include garlic, cayenne pepper and green tea. Aim to consume two to three servings of these herbs or herbal teas daily.

The American Heart Association, Mayo Clinic and Cleveland Clinic recommend getting antioxidants from whole foods and a wide variety of sources. Glutathione is a peptide consisting of three key amino acids that plays several vital roles in the body, including helping with protein use, creation of enzymes, detoxification, digestion of fats and destruction of cancer cells.

Glutathione peroxidase can prevent lipid peroxidation, which can fight inflammation. Derived naturally from foods like berries and leafy greens, quercetin seems to be safe for almost everyone and poses little risk.

Most studies have found little to no side effects in people eating nutrient-dense diets high in quercetin or taking supplements by mouth short term. Amounts up to milligrams taken twice daily for 12 weeks appear to be very safe for helping manage a number of inflammatory health problems, including heart disease and blood vessel problems, allergies, infections, chronic fatigue and symptoms related to autoimmune disorders like arthritis.

Lutein has benefits for the eyes, skin, arteries, heart and immune system, although food sources of antioxidants seem to be generally more effective and safer than supplements.

Some evidence shows that people who obtain more lutein from their diets experience lower rates of breast, colon, cervical and lung cancers. Known for improving immunity, vitamin C helps protect against colds, the flu, and potentially cancer, skin and eye problems. Resveratrol is an active ingredient found in cocoa, red grapes and dark berries, such as lingonberries, blueberries, mulberries and bilberries.

Astaxanthin is found in wild-caught salmon and krill and has benefits like reducing age spots, boosting energy levels, supporting joint health and preventing symptoms of ADHD. Selenium is a trace mineral found naturally in the soil that also appears in certain foods, and there are even small amounts in water.

Selenium benefits adrenal and thyroid health and helps protect cognition. It may also fight off viruses, defend against heart disease and slow down symptoms correlated with other serious conditions, like asthma. Chlorophyll is very helpful for detoxification and linked to natural cancer prevention, blocking carcinogenic effects within the body, and protecting DNA from damage caused by toxins or stress.

Cooking can alter the content of antioxidants in food, and certain cooking methods can have a different impact on antioxidant levels. One study published in Preventive Nutrition and Food Science evaluated the effects of different cooking methods on the antioxidant content of red pepper to determine which methods can help minimize antioxidant loss.

Interestingly, researchers found that stir-frying and roasting helped retain the most antioxidants, while boiling and steaming caused significant reductions in antioxidant levels. Ascorbic acid, also known as vitamin C, is a water-soluble vitamin, which means that it dissolves in water.

For this reason, cooking food in water with methods like boiling can cause a huge reduction in antioxidant content. However, not all compounds on the antioxidants list are affected in the same way by cooking.

They reduce the harm from exposure to free radicals, compounds around us that cause cellular stress. Antioxidants are predominantly found in colorful plant foods like leafy greens, nuts, and berries. This article explores why antioxidants are good for you and the best places to find them in your diet.

Every day, our cells are exposed to compounds called free radicals , which are unstable molecules regularly produced by our bodies as a normal byproduct of metabolism. For instance, our bodies produce free radicals after exposure to environmental toxins, certain foods we eat, and ultraviolet light.

They trigger oxidative stress , which is hard on our cells and can promote disease and aging. However, free radicals also serve some beneficial purposes for our health. For instance, they're deployed by the immune system to fight off infections. The key is to balance free radicals and antioxidants in the body so both can do their jobs but not cross the line into being harmful.

Antioxidants neutralize free radicals through a process of transferring electrons. This helps turn free radicals "off" to prevent them from harming our cells and DNA.

Without antioxidants, free radicals would have devastating effects on our health. Specifically, a regular supply of antioxidants through food has been associated with a reduced risk for conditions like heart disease, cancers, and other morbidities.

Free radicals are unstable compounds that can cause damage at a cellular level, promoting disease and aging. They are produced as a byproduct of normal metabolism after harmful exposures to environmental toxins and pollution, some viruses, radon, asbestos, tobacco smoke, and ultraviolet light.

Antioxidants play a crucial role in supporting and protecting our health. The same goes for plants, animals, and other living things with antioxidant defense mechanisms.

As such, antioxidants naturally occur in many foods you may already include in your diet. While they are predominantly found in whole plant foods, there are also some animal-derived sources of antioxidants. The following are some of the major types of antioxidants and where they can be found in food:.

This isn't an exhaustive list, but it does underline that the best way to incorporate antioxidants into your diet is to consume a variety of healthy, minimally processed foods. The best sources are fruits, vegetables, nuts, seeds, legumes, and certain fish.

Eating a diet low in antioxidants can set you up for a higher risk of disease. Without antioxidants, your cells are more vulnerable to damage from free radicals. Diet patterns high in saturated and trans fats, sodium, and added sugar but low in fiber and antioxidants have been found to promote the development of chronic diseases.

Research suggests that eating this way negatively alters the community of bacteria in your digestive tract, called your gut microbiome.

An imbalanced gut microbiome promotes inflammation, increasing the risk of disease. Antioxidants are also sold in supplemental form, often advertised as "ultra" or "high dose. And, there aren't necessarily antioxidants that are better than others. A combination is optimal. Taking high amounts of isolated antioxidants can harm your health, with their risk outweighing their potential benefits.

Megadoses can be toxic and, in some cases, promote oxidation rather than prevent it. For example, glutathione GSH is an antioxidant your body produces. While it has anticancer benefits, research shows that excess GSH promotes cancerous tumor growth.

Research also indicates that it's not necessarily the antioxidant that has benefits but how it works with other compounds in whole foods to provide benefits.

A small randomized controlled trial found that, although healthy participants were given either orange juice or sugar water with the same amount of vitamin C, the orange juice offered significantly more antioxidant benefits. Overall, the best way to get a variety of antioxidants in the safest and most beneficial way is to consume a diet full of antioxidant-rich foods.

If you're looking for ways to include more antioxidants in your diet, consider these ideas:. The best way to reap the benefits of dietary antioxidants is to include fruits, vegetables, legumes, nuts, seeds, and certain fish.

Consider what you currently eat for breakfast, lunch, and dinner, and identify some places you can incorporate more antioxidant-rich foods regularly. Antioxidants are compounds that help protect us from disease and the effects of aging. While your body makes some antioxidants, it's important to incorporate them into your diet regularly.

Find them in fruits, vegetables, nuts, seeds, legumes, and certain fish like salmon. It's best to get your antioxidants from these types of minimally processed foods versus high-dose antioxidant supplements, as these may negatively affect health.

You probably already consume antioxidants and can add others to your meals and snacks with little effort. Free radical properties, source and targets, antioxidant consumption and health. Aune D. Plant foods, antioxidant biomarkers, and the risk of cardiovascular disease, cancer, and mortality: a review of the evidence.

Adv Nutr. Khan UM, Sevindik M, Zarrabi A, et al. Lycopene: food sources, biological activities, and human health benefits. Oxid Med Cell Longev. NIH National Institutes of Health Office of Dietary Supplements. Vitamin C. Rizvi S, Raza ST, Ahmed F, Ahmad A, Abbas S, Mahdi F. The role of vitamin E in human health and some diseases.

Sultan Qaboos Univ Med J. Imran M, Ghorat F, Ul-Haq I, et al. Lycopene as a natural antioxidant used to prevent human health disorders. Antioxidants Basel. Kiełczykowska M, Kocot J, Paździor M, Musik I. Selenium - a fascinating antioxidant of protective properties.

Adv Clin Exp Med. Anand R, Mohan L, Bharadvaja N. Disease prevention and treatment using β-carotene: the ultimate provitamin A. Rev Bras Farmacogn. Viruses and infections attack them. Free radicals also can damage your cells and DNA. Some cells can heal from the damage, while others cannot.

Scientists believe molecules called free radicals can contribute to the aging process. They also may play a part in certain health conditions, like cancer, diabetes, and heart disease. Antioxidants are substances that help stop or limit damage caused by free radicals.

Your body uses antioxidants to balance free radicals. This keeps them from causing damage to other cells. Antioxidants can protect and reverse some of the damage. They also boost your immunity. There are things you can do to help fight free radicals and reduce the damage they cause.

You can stop smoking, get sun exposure safely, and eat healthy. Antioxidants may also help. Your body produces some antioxidants. The best way to get additional antioxidants is through certain foods and vitamins.

Common antioxidants include:. You can get most of these antioxidants by eating a healthy diet. This includes a mix of colorful fruits and vegetables. Whole grains, seeds, and nuts also provide good nutrients. Each antioxidant has a different chemical makeup. Each one provides different health benefits.

Too much of one antioxidant can be harmful. Talk to your doctor before changing your diet or taking supplements. Doctors recommend eating a balanced diet that include fresh fruits and vegetables. A lot of produce has natural antioxidants. It also contains important minerals, fiber, and other vitamins.

Eating healthy can help lower your risk of certain diseases. However, antioxidants alone do not prevent chronic conditions. Some people choose to take antioxidant supplements. However, many are not balanced.

They are also not approved or regulated by the U. Food and Drug Administration FDA. This means that the ingredients and suggested dose listed on the bottle may not be correct. Your body responds to antioxidants in different ways.

Some can cause health risks or negative effects on your health. For instance, people who smoke are in danger of getting lung cancer. Taking high doses of beta-carotene can increase your risk of this disease.

Antioxidants also can interact with some medicines. Talk to your doctor before taking high doses of antioxidants. They can help you determine what, if any, supplements are right for you. National Cancer Institute: Antioxidants and Cancer Prevention.

National Institutes of Health, MedlinePlus: Antioxidants. Last Updated: June 8, This information provides a general overview and may not apply to everyone. Talk to your family doctor to find out if this information applies to you and to get more information on this subject.

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