High-dose antioxidant supplements can also interfere with medicines. Vitamin E supplements can have a blood-thinning effect and increase the risk of bleeding in people who are already taking blood-thinning medicines. Some studies have suggested that taking antioxidant supplements during cancer treatment might interfere with the effectiveness of the treatment.

Inform your doctor if starting supplements of any kind. One possible reason why many studies on antioxidant supplements do not show a health benefit is because antioxidants tend to work best in combination with other nutrients, plant chemicals, and even other antioxidants.

For example, a cup of fresh strawberries contains about 80 mg of vitamin C, a nutrient classified as having high antioxidant activity. Polyphenols also have many other chemical properties besides their ability to serve as antioxidants. There is a question if a nutrient with antioxidant activity can cause the opposite effect with pro-oxidant activity if too much is taken.

This is why using an antioxidant supplement with a single isolated substance may not be an effective strategy for everyone.

Differences in the amount and type of antioxidants in foods versus those in supplements might also influence their effects. For example, there are eight chemical forms of vitamin E present in foods.

However, vitamin E supplements typically only include one form, alpha-tocopherol. Epidemiological prospective studies show that higher intakes of antioxidant-rich fruits, vegetables, and legumes are associated with a lower risk of chronic oxidative stress-related diseases like cardiovascular diseases , cancer, and deaths from all causes.

The following are nutrients with antioxidant activity and the foods in which they are found:. Excessive free radicals contribute to chronic diseases including cancer, heart disease, cognitive decline, and vision loss. Keep in mind that most of the trials conducted have had fundamental limitations due to their relatively short duration and inclusion of people with existing disease.

At the same time, abundant evidence suggests that eating whole in fruits , vegetables , and whole grains —all rich in networks of naturally occurring antioxidants and their helper molecules—provides protection against many scourges of aging.

The contents of this website are for educational purposes and are not intended to offer personal medical advice. You should seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.

Never disregard professional medical advice or delay in seeking it because of something you have read on this website.

The Nutrition Source does not recommend or endorse any products. Skip to content The Nutrition Source. The Nutrition Source Menu. Search for:. Home Nutrition News What Should I Eat? In , a rating tool called the Oxygen Radical Absorbance Capacity ORAC was created by scientists from the National Institute on Aging and the United States Department of Agriculture USDA.

It was used to measure the antioxidant capacity of foods. The USDA provided an ORAC database on its website highlighting foods with high ORAC scores, including cocoa, berries, spices, and legumes.

Blueberries and other foods topping the list were heavily promoted in the popular press as disease-fighters even if the science was weak, from cancer to brain health to heart disease. However, 20 years later the USDA retracted the information and removed the database after determining that antioxidants have many functions, not all of which are related to free radical activity.

Although this was not a primary endpoint for the trial, it nevertheless represents an important outcome. In the Heart Outcomes Prevention Evaluation HOPE trial, the rates of major cardiovascular events were essentially the same in the vitamin E A recent trial of vitamin E in Israel, for example, showed a marked reduction in coronary heart disease among people with type 2 diabetes who have a common genetic predisposition for greater oxidative stress.

In the Supplementation en Vitamines et Mineraux Antioxydants SU. MAX study, 13, French men and women took a single daily capsule that contained mg vitamin C, 30 mg vitamin E, 6 mg beta-carotene, mcg selenium, and 20 mg zinc, or a placebo, for seven and a half years.

The vitamins had no effect on overall rates of cardiovascular disease. Lung disease A study from the Journal of Respiratory Research found that different isoforms of vitamin E called tocopherols had opposing effects on lung function.

Cancer When it comes to cancer prevention, the picture remains inconclusive for antioxidant supplements. MAX randomized placebo-controlled trial showed a reduction in cancer risk and all-cause mortality among men taking an antioxidant cocktail low doses of vitamins C and E, beta-carotene, selenium, and zinc but no apparent effect in women, possibly because men tended to have low blood levels of beta-carotene and other vitamins at the beginning of the study.

Age-related eye disease A six-year trial, the Age-Related Eye Disease Study AREDS , found that a combination of vitamin C, vitamin E, beta-carotene, and zinc offered some protection against the development of advanced age-related macular degeneration, but not cataracts, in people who were at high risk of the disease.

However, relatively short trials of lutein supplementation for age-related macular degeneration have yielded conflicting findings.

The study found that people taking the vitamins were less likely to progress to late-stage AMD and vision loss. However, the study authors noted that taking lutein and zeaxanthin alone or vitamin E alone did not have a beneficial effect on these eye conditions. The Selenium and Vitamin E Cancer Prevention Trial SELECT Eye Endpoints Study, which followed 11, men for a mean of five years, did not find that vitamin E and selenium supplements, in combination or alone, protected from age-related cataracts.

It did not find that antioxidant supplements of vitamin E or selenium, alone or in combination, protected against dementia compared with a placebo. Early death A meta-analysis of 68 antioxidant supplement trials found that taking beta-carotene and vitamin A and E supplements increased the risk of dying.

It was also difficult to compare interventions because the types of supplements, the dosages taken, and the length of time they were taken varied widely.

The same authors conducted another systematic review of 78 randomized clinical trials on antioxidant supplements including beta-carotene, vitamin A, vitamin C, vitamin E, and selenium alone or in combination. The study found that both people who were healthy and those with diseases taking beta-carotene and vitamin E supplements had a higher rate of death.

The duration of the studies varied widely from one month to 12 years, with varying dosages. The first inkling came in a large trial of beta-carotene conducted among men in Finland who were heavy smokers, and therefore at high risk for developing lung cancer.

The trial was stopped early when researchers saw a significant increase in lung cancer among those taking the supplement compared to those taking the placebo. Again, an increase in lung cancer was seen in the supplement group.

MAX trial, rates of skin cancer were higher in women who were assigned to take vitamin C, vitamin E, beta-carotene, selenium, and zinc. These results came from the Selenium and Vitamin E Cancer Prevention Trial SELECT that followed 35, men for up to 12 years. References National Center for Complementary and Integrative Health NCCIH.

Antioxidants: In Depth. Carlsen MH, Halvorsen BL, Holte K, Bøhn SK, Dragland S, Sampson L, Willey C, Senoo H, Umezono Y, Sanada C, Barikmo I.

Strawberries are sweet, versatile, and rich in vitamin C. They also contain a lot of the antioxidant anthocyanin , which gives them their red color. Research has shown that anthocyanins may help reduce the risk of heart disease by reducing levels of LDL bad cholesterol and raising HDL good cholesterol.

Learn about the health benefits of strawberries. Artichokes are a great source of dietary fiber, minerals, and antioxidants. They are especially rich in an antioxidant known as chlorogenic acid, which may help reduce the risk of certain cancers, type 2 diabetes, and heart disease.

That said, the antioxidant content of artichokes can vary depending on how they are prepared. Learn about the health benefits of artichokes. Goji berries are often marketed as a superfood because they are rich in vitamins and minerals.

Goji berries also contain unique antioxidants known as Lycium barbarum polysaccharides, which have been linked to a reduced risk of heart disease and cancer. Moreover, there is limited research on the effects of goji berries on humans. Though these support their health benefits, more human-based research is needed.

Learn about the health benefits of goji berries. Raspberries are a great source of dietary fiber, vitamin C, and manganese. A review of five studies also concluded that the anti-inflammatory and antioxidant properties of black raspberries may slow down and suppress the effects of a variety of cancers.

Plus, the antioxidants in raspberries, especially anthocyanins, may reduce inflammation and oxidative stress. This may reduce the chance of developing heart disease. That said, most of the evidence for the health benefits of raspberries is from test-tube studies, so more human-focused research is needed.

Learn about the health benefits of raspberries. Kale is one of the most nutritious greens on the planet and is rich in calcium, and vitamins A, K, and C.

This is because red varieties of kale contain more anthocyanin antioxidants as well as several other antioxidants that give them their vibrant color. Learn about the health benefits of kale.

Also known as purple cabbage, red cabbage is rich in vitamins C, K, and A, and has a high antioxidant content. It, too, contains anthocyanins, which give it its color and may help reduce inflammation, protect against heart disease, and reduce the risk of certain cancers.

That said, the volume of antioxidants in red cabbage varies depending on how you cook it. Learn about the health benefits of red cabbage. Beans are a diverse group of legumes that are inexpensive and healthy. They are also incredibly high in fiber, which can help keep your bowel movements regular.

Beans are also one of the best vegetable sources of antioxidants, containing a particular antioxidant called kaempferol, which may help with things like reducing chronic inflammation and suppressing cancer growth.

That said, most of the research supporting the benefits of kaempferol has been in animals or test tubes, so more human-based studies are needed. Learn about the health benefits of beans. Beets, also known as beetroot , are a great source of fiber, potassium, iron, folate, and antioxidants. These give beets their reddish color and have been linked to health benefits.

For example, several test-tube studies have linked betalains to a lower risk of cancers in the colon and digestive tract. Learn more about the health benefits of beats. Spinach is loaded with vitamins, minerals, and antioxidants, and is incredibly low in calories. Learn about the health benefits of spinach.

Spices such as ginger , turmeric , and garlic , as well as herbs such as rosemary , parsley , and sage , all contain a variety of minerals, vitamins, and important antioxidants. Dark chocolate generally contains less sugar and more cacao solids than milk chocolate. It is also rich in antioxidants and some minerals.

Antioxidants are mostly found in plant foods. They are natural molecules that help neutralize harmful free radicals in our bodies. Free radicals are…. Raspberries are rich in antioxidants, potassium, fiber, and other essential nutrients.

Learn more about their benefits and get some tips on how to…. What are micronutrients? Read on to learn more about these essential vitamins and minerals, the role they play in supporting health, as well as….

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Medical News Today. Health Conditions Health Products Discover Tools Connect. A guide to antioxidant foods. Medically reviewed by Katherine Marengo LDN, R. Blueberries Dark chocolate Artichokes Pecans Strawberries Red cabbage Raspberries Beans Purple or red grapes Spinach Beets Kale Orange vegetables Summary Antioxidants are compounds that may help delay or even prevent cell damage in the body.

Share on Pinterest. Dark chocolate. Red cabbage. Share on Pinterest Research has shown that pinto beans could help in suppressing certain types of cancer.

Purple or red grapes. Orange vegetables. How we reviewed this article: Sources. Medical News Today has strict sourcing guidelines and draws only from peer-reviewed studies, academic research institutions, and medical journals and associations. We avoid using tertiary references.

We link primary sources — including studies, scientific references, and statistics — within each article and also list them in the resources section at the bottom of our articles. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.

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A study from the United Kingdom in which 72, people were followed for an average of 9 years showed that higher intakes of fruits and vegetables were associated with a lower risk of cataracts.

For example, in a study of adults living in rural areas in the United States, eating at least five servings of fruits and vegetables daily was associated with several other factors that might affect health, such as getting at least moderate physical activity and having had a routine medical exam in the past year.

Antioxidants consumed as purified chemicals might act differently than those consumed in foods, which contain complex mixtures of substances. The high doses of antioxidants in dietary supplements may have different effects than the smaller amounts in foods. Can antioxidant supplements help to prevent cancer?

In , the U. Preventive Services Task Force, an independent panel of experts that makes evidence-based recommendations about disease prevention, recommended against the use of beta-carotene or vitamin E supplements for cancer prevention. They also concluded that the evidence is insufficient to make recommendations about supplements of other single nutrients or pairs of nutrients.

Beta-carotene supplementation led to an increase in risk of lung cancer, with the strongest evidence of an increase in risk in people at high risk of this type of cancer smokers and people with occupational exposure to asbestos , as well as an increased risk of death from cardiovascular disease.

Can antioxidant supplements help to prevent cardiovascular disease? Preventive Services Task Force recommended against the use of beta-carotene or vitamin E supplements for prevention of cardiovascular disease.

Beta-carotene supplementation led to an increase in risk of lung cancer, with the strongest evidence of an increase in risk in people at high risk of this type of cancer smokers and people with occupational exposure to asbestos , and an increase in deaths from cardiovascular disease.

Can antioxidant supplements help to prevent cataracts? Are antioxidant supplements helpful for age-related macular degeneration AMD? A review that examined the results of 5 studies 76, participants did not find any significant benefit of vitamin E, vitamin C, or beta-carotene supplementation in preventing or delaying the onset of AMD.

For people who already have AMD, supplements containing a combination of antioxidants and zinc may slow the progression of the disease. The evidence for this comes from two large studies sponsored by the National Institutes of Health—the Age-Related Eye Disease Study AREDS and Age-Related Eye Disease Study 2 AREDS2.

AREDS evaluated the effects of a dietary supplement containing high doses of vitamins C and E, beta-carotene, zinc, and copper on the progression of AMD. Almost 4, people participated in this study, including 3, who had AMD. Among people with intermediate AMD, the supplement reduced the risk of developing advanced AMD by about 25 percent.

AREDS2 tested modifications to the original AREDS formula in about 4, people who were at high risk of progressing to advanced AMD. Participants were randomly assigned to groups that received the original formula or various modified versions. The modifications included removing beta-carotene and adding lutein and zeaxanthin two carotenoids that are found in the eye.

Because the link between beta-carotene and an increased risk of lung cancer in smokers was known before this study started, current smokers were not assigned to groups that received beta-carotene; only nonsmokers and former smokers were included in those groups.

After 10 years of follow-up, lutein and zeaxanthin proved to be more effective than beta-carotene in reducing the risk of progression to advanced AMD. Beta-carotene increased lung cancer risk among former smokers, but lutein and zeaxanthin did not.

Are antioxidants helpful for preserving cognitive function? Two recent reviews looked at evidence related to this topic and found mixed results.

There was low-certainty evidence of better overall cognitive function after taking beta-carotene for 18 years and after taking vitamin C for 5 to 10 years, but no effects were seen after shorter periods of supplementation or after taking vitamin E. The effects seen in the studies were small.

Another review looked at studies of vitamin and mineral supplementation in people who already have mild cognitive impairment. Two of the studies involved antioxidants. In one study participants , high-dose supplementation with vitamin E for 3 years did not have a significant effect on progression of mild cognitive impairment to dementia.

In the other study, which involved combined vitamin E and C supplementation participants , the evidence was too low in quality for any conclusions to be reached about cognitive effects. Are antioxidant supplements safe? Not necessarily. Antioxidants can have harmful effects when taken at high doses.

These effects have been seen primarily in people at high risk, such as smokers. Vitamin E supplements may also interact with certain medicines, including anticoagulant or antiplatelet medicines.

High doses of vitamin C can cause diarrhea, nausea, and stomach cramps. Vitamin C supplements may also interact with cancer treatments, such as chemotherapy and radiation therapy, and they can worsen iron overload in people with hemochromatosis, a condition that causes the body to store too much iron.

Combinations of antioxidants may have undesirable effects. For example, in one study, a combination of vitamin E, vitamin C, selenium, and beta-carotene reduced the cholesterol-lowering effects of two drugs taken together for this purpose.

Tips To Consider. If you have age-related macular degeneration, consult your health care providers to determine whether supplements of the types used in the AREDS or AREDS2 trials are appropriate for you. If you are considering a dietary supplement, first get information on it from reliable sources.

Keep in mind that dietary supplements may interact with medications or other supplements and may contain ingredients not listed on the label. Your health care provider can advise you. Take charge of your health—talk with your health care providers about any complementary health approaches you use.

Together, you can make shared, well-informed decisions. For More Information. NCCIH Clearinghouse The NCCIH Clearinghouse provides information on NCCIH and complementary and integrative health approaches, including publications and searches of Federal databases of scientific and medical literature.

Toll-free in the U. gov Email: info nccih. Know the Science NCCIH and the National Institutes of Health NIH provide tools to help you understand the basics and terminology of scientific research so you can make well-informed decisions about your health. Explaining How Research Works NIH Know the Science: How To Make Sense of a Scientific Journal Article Understanding Clinical Studies NIH.

PubMed® A service of the National Library of Medicine, PubMed® contains publication information and in most cases brief summaries of articles from scientific and medical journals. Key References. Aune D, Giovannucci E, Boffetta P, et al. Fruit and vegetable intake and the risk of cardiovascular disease, total cancer and all-cause mortality—a systematic review and dose-response meta-analysis of prospective studies.

International Journal of Epidemiology. Bjelakovic G, Nikolova D, Gluud LL, et al. Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases. Cochrane Database of Systematic Reviews.

Accessed at cochranelibrary. com on May 10, Chew EY, Clemons TE, Agrón E, et al. JAMA Ophthalmology. Evans JR, Lawrenson JG. Antioxidant vitamin and mineral supplements for preventing age-related macular degeneration.

com on March 22, Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration. Fan H, Han X, Shang X, et al.

Fruit and vegetable intake and the risk of cataract: insights from the UK Biobank study. Eye London. March 27, He FJ, Nowson CA, Lucas M, et al. Increased consumption of fruit and vegetables is related to a reduced risk of coronary heart disease: meta-analysis of cohort studies.

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Antioxidant vitamins and ageing. Sub-cellular Biochemistry. National Eye Institute. Vitamin and mineral supplements for the primary prevention of cardiovascular disease and cancer.

Updated evidence report and systematic review for the US Preventive Services Task Force. Rutjes AW, Denton DA, Di Nisio M, et al. Vitamin and mineral supplementation for maintaining cognitive function in cognitively healthy people in mid and late life.

The Nutrition Source, Harvard T. Chan School of Public Health. US Preventive Services Task Force, et al. Vitamin, mineral, and multivitamin supplementation to prevent cardiovascular disease and cancer. US Preventive Services Task Force recommendation statement.

Other References. Jideani AIO, Silungwe H, Takalani T, Omolola AO, Udeh HO, Anyasi TA. Antioxidant-rich natural fruit and vegetable products and human health. International Journal of Food Properties. Goyal S, Kaur TJ. Antioxidants: Dietary scavengers in lifestyle diseases.

Journal of Pharmacognosy and Phytochemistry. National Cancer Institute. Antioxidants and cancer prevention. American Academy of Family Physicians. Antioxidants: what you need to know. National Center for Complementary and Integrative Health. Antioxidants: in depth. Conti V, Izzo V, Corbi G, et al.

Antioxidant supplementation in the treatment of aging-associated diseases. Front Pharmacol. Use limited data to select advertising. Create profiles for personalised advertising. Use profiles to select personalised advertising. Create profiles to personalise content.

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