In part, this is because fruits and vegetables, which are rich in antioxidants, are associated with many health benefits, including a reduced risk of disease 1.

Yet, there is strong evidence to suggest that you may be doing your health a disservice by supplementing with antioxidants. Antioxidant supplements contain concentrated forms of antioxidants, which are substances that stabilize free radicals. Environmental factors, such as UV exposure, air pollutants, tobacco smoke and industrial chemicals like pesticides , are also sources of free radicals 2.

Over time, this contributes to aging and the development of diseases, including cancer 3. The main antioxidants that help regulate free radicals in your body are the vitamins A, C, and E and the mineral selenium.

The health detriments associated with taking antioxidant supplements outnumber its potential benefits. Your body naturally produces free radicals as a byproduct of energy metabolism during exercise.

The harder and longer you exercise , the more free radicals your body produces 6. However, several studies have shown that taking antioxidant supplements — specifically vitamins C and E — can interfere with how your body adapts to exercise and even eliminate some of the health benefits associated with exercise 8 , 9 , 10 , Since antioxidants neutralize free radicals, taking antioxidant supplements have been speculated to decrease the risk of developing or dying from cancer Several meta-analyses, however, have shown that taking antioxidant supplements does neither reduce the risk of many types of cancers nor reduce the risk of dying from them once diagnosed, In fact, they may even increase the risk of certain cancers 14 , 15 , 16 , In addition, several meta-analyses have found that beta-carotene supplements, a precursor of vitamin A, increases the risk of bladder cancer, and, in people who smoke, the risk of lung cancer as well 18 , 19 , 20 , The exception is selenium , which may help prevent cancer in people with low levels of the mineral or in people with an elevated risk of cancer.

However, more research is needed before selenium can be recommended for this purpose 16 , 22 , 23 , Vitamin A is important for fetal growth and development, but at high doses, vitamin A supplements can increase the risk of birth defects 25 , Therefore, women who might be or are pregnant should not take high doses of vitamin A supplements These supplements are only recommended for pregnant women in areas where vitamin A deficiency is prevalent, such as in Africa and Southeast Asia 28 , Beta-carotene, the precursor of vitamin A, is not shown to lead to birth defects.

But since taking the supplement long-term is associated with cancer, pregnant women should consult with their physician before taking beta-carotene supplements 30 , Though antioxidant supplements are generally not recommended for a variety of reasons, the antioxidant vitamin C may benefit people with the common cold or those who smoke.

Vitamin C has not been shown to prevent the common cold , but it may reduce its severity and duration. In addition, higher doses may cause stomach upset Similarly, exposure to secondhand smoke also increases vitamin C needs Yet, this additional need for vitamin C can be easily met through diet and without taking antioxidant supplements.

For the most part, the use of antioxidant supplements is discouraged, though the antioxidant vitamin C can benefit people with the common cold or those who smoke. 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.

Putting them on your food or in your cooking can help reduce oxidative stress, which can help reduce the chance of developing various health conditions. Depending on the specific herb or spice, these diseases include high blood pressure, heart disease, kidney disease, and diabetes.

Okra is a flowering plant with edible seed pods that grows best in warm and tropical climates. It also contains antioxidants that are anti-inflammatory and may help reduce high cholesterol and blood pressure, as well as protect heart and brain health. Read more about the health benefits of okra.

That said, some have more bioactive compounds than others, such as vitamins E and C , for example. Drinks that are high in antioxidants include green tea, pomegranate juice, and acai juice. They protect your body from potentially harmful molecules known as free radicals, which can accumulate and promote oxidative stress.

Oxidative stress raises the risk of heart disease, cancers, type 2 diabetes, and many other chronic conditions.

Eating a diet rich in antioxidants can help neutralize free radicals and reduce the risk of these chronic diseases. By eating a wide variety of the foods in this article, you can boost your blood levels of antioxidants and reap their many health benefits.

Our experts continually monitor the health and wellness space, and we update our articles when new information becomes available. VIEW ALL HISTORY. This article is based on scientific evidence, written by experts and fact checked by experts.

Our team of licensed nutritionists and dietitians strive to be objective, unbiased, honest and to present both sides of the argument. This article contains scientific references. The numbers in the parentheses 1, 2, 3 are clickable links to peer-reviewed scientific papers. Brain fog is a symptom of another medical condition.

Chronic inflammation refers to a response by your immune system that sticks around long after infection or injury. Learn the common symptoms and…. Inflammation is one way your body fights infection, injury, and disease. Sometimes inflammation can become a painful problem. Your doctor can perform….

What is oxidative stress, and why does it matter? We explain how this imbalance affects your body and ways to prevent it. A Quiz for Teens Are You a Workaholic?

How Well Do You Sleep? Green Tea Green tea has been consumed for centuries in India, China, Japan, and Iran, and in traditional Chinese and Indian medicine, it has been used as a stimulant for somnolence , diuretic to promote the excretion of urine , astringent to control bleeding and help heal wounds , and to improve heart health.

Other traditional uses of green tea include treating flatulence, regulating body temperature and blood glucose levels, promoting digestion, and improving mental processes. There are three main varieties of tea--green, black, and oolong Camellia sinensis. Green and oolong teas are more commonly consumed in Asian countries, while black tea is most popular in the U.

The difference between the teas is in their processing. Green tea is prepared from unfermented leaves, oolong tea from partially fermented leaves, and black tea from fully fermented leaves. The more the leaves are fermented, the lower the polyphenol content and the higher the caffeine content.

Polyphenols are chemicals that act as powerful antioxidants. Compared with black tea, green tea has a higher polyphenol content; however, black tea has roughly two to three times the caffeine content of green tea.

Green tea contains six primary catechin compounds: catechin, gallocatechin, epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate also known as EGCG. EGCG is considered to be the most active component in green tea and is the best researched of all the green tea polyphenols.

Green tea also contains alkaloids, including caffeine, theobromine, and theophylline. These alkaloids provide green tea's stimulant effects.

Consistent tea consumption leads to a significant increase in the antioxidant capacity of the blood. Beneficial effects of increased antioxidant capacity in the body may be the reduction of oxidative damage to important biomolecules.

The scientific support is strongest for the protection of DNA from oxidative damage after black or green tea consumption. In fact, this nu­ trient plays a major role in the manufacture and defense of our connective tissue, the elaborate matrix that holds the body together.

It serves as a primary ingredient of collagen, a glue-like substance that binds cells together to form tissues. Vitamin C helps some of our most important body systems. First and foremost, it helps the immune system to fight off foreign invaders and tumor cells. In addition, vitamin C supports the cardiovascular system by facilitating fat metabolism and protecting tissues from free radical damage.

It also assists the nervous system by converting certain amino acids into neurotransmitters. The skin, teeth, and bones also benefit from vitamin C's collagen-forming and invader-resisting properties; this vitamin contributes to the maintenance of healthy bones, the prevention of periodontal disease, and the healing of wounds.

It combats inflammation and pain by inhibiting the secretion of prostaglandins, which contribute to such symptoms. It works in collaboration with vitamin E, a fat-soluble antioxidant, and the enzyme glutathione peroxidase to stop free radical chain reactions.

Vitamin C is an excellent source of electrons; therefore, it can donate electrons to free radicals, such as hydroxyl and superoxide radicals, and quench their reactivity. Large concentrations of vitamin C can be found in fruits such as oranges, grapefruits, tangerines, lemons, and limes.

Vitamin C and bioflavonoids--the water-soluble substances that help to protect human capillaries--are found in the white linings of these and other plants.

Many vegetables also contain vitamin C, including tomatoes, broccoli, green and red bell peppers, raw lettuce, and other leafy greens. Studies suggest that vitamin C's antioxidant mechanisms may help to prevent cancer in several ways.

For example, vitamin C combats the peroxidation of lipids, which has been linked to degeneration and aging. The recommended daily allowance of vitamin C is mg. Each form has its own biological activity, which is the measure of potency or functional use in the body.

Alpha-tocopherol is the most active form of vitamin E in humans. It is also a powerful biological antioxidant. Vitamin E supplements are usually sold as alpha-tocopheryl acetate, a form that protects its ability to function as an antioxidant. The synthetic form is labeled "D, L" while the natural form is labeled "D.

Studies are under way to determine whether vitamin E, through its ability to limit production of free radicals, might help prevent or delay the development of some chronic diseases such as cardiac diseases. Vitamin E has also been shown to play a role in immune function, DNA repair, and other metabolic processes.

Selenium is used by our bodies to produce glutathione peroxidase, a component of the body's natural antioxidant defense system that is manufactured in the liver.

It works with vitamin E to protect cell membranes from damage caused by harmful free radicals and helps to detoxify harmful compounds in the liver. Additionally, some glutathione is released into the bloodstream, where it helps to maintain the integrity of red blood cells while protecting immune system white blood cells as part of the body's defense.

Eighteen patients received no supplementation, 14 patients received oral selenium, and 13 patients received oral beta-carotene for a period of one year.

Between three and six months, glutathione activity increased significantly in patients treated with selenium, compared with those treated with placebo. Only a slight increase was found following treatment with beta-carotene.

The researchers stated that because glutathione plays an important role in the natural enzymatic defense system in detoxifying hydrogen peroxide in water, selenium supplementation could be of great interest in protecting cells against oxidative stress.

Because of the risk of toxic levels of selenium building up in the system, patients should avoid taking high doses mcg or more at one time, or mcg daily for an extended period of time. Patients must also be aware of the amount of selenium they take in from seafood, whole grains, oats, and nuts.

Most of these antioxidants are affordable and readily available to anyone who wants them. Research indicates promising results on the protective effects of antioxidants to strengthen the immune system to fight toxins in human body. Pharmacists are in an exceptional position to explain proper dosages to their patients and to clarify the roles of various synthetic and natural antioxidants available on the market.

They can also explain the benefits patients receive from scavenging free radicals in their bodies to reduce cell and tissue damage. Di Mascio P, Kaiser S, Sies H. Lycopene as the most efficient biological carotenoid singlet oxygen quencher.

Arch Biochem Biophys. Saljoughian M. Lycopene: nature's powerful antioxidant. UC Berkeley wellness letter.

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.

Journal of Human Hypertension. Lutfiyya MN, Chang LF, Lipsky MS. BMC Public Health. Mathew MC, Ervin A-M, Tao J, et al.

Antioxidant vitamin supplementation for preventing and slowing the progression of age-related cataract. com on May 17, McCleery J, Abraham RP, Denton DA, et al. Vitamin and mineral supplementation for preventing dementia or delaying cognitive decline in people with mild cognitive impairment.

Milasav I, Ribarič S, Poljsak B. 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. Finley JW, Kong A-N, Hintze KJ, et al. Antioxidants in foods: state of the science important to the food industry. Journal of Agricultural and Food Chemistry.

Forman HJ, Zhang H. Targeting oxidative stress in disease: promise and limitations of antioxidant therapy. Nature Reviews. Drug Discovery. National Cancer Institute. These alkaloids provide green tea's stimulant effects. Consistent tea consumption leads to a significant increase in the antioxidant capacity of the blood.

Beneficial effects of increased antioxidant capacity in the body may be the reduction of oxidative damage to important biomolecules. The scientific support is strongest for the protection of DNA from oxidative damage after black or green tea consumption.

In fact, this nu­ trient plays a major role in the manufacture and defense of our connective tissue, the elaborate matrix that holds the body together.

It serves as a primary ingredient of collagen, a glue-like substance that binds cells together to form tissues. Vitamin C helps some of our most important body systems.

First and foremost, it helps the immune system to fight off foreign invaders and tumor cells. In addition, vitamin C supports the cardiovascular system by facilitating fat metabolism and protecting tissues from free radical damage.

It also assists the nervous system by converting certain amino acids into neurotransmitters. The skin, teeth, and bones also benefit from vitamin C's collagen-forming and invader-resisting properties; this vitamin contributes to the maintenance of healthy bones, the prevention of periodontal disease, and the healing of wounds.

It combats inflammation and pain by inhibiting the secretion of prostaglandins, which contribute to such symptoms. It works in collaboration with vitamin E, a fat-soluble antioxidant, and the enzyme glutathione peroxidase to stop free radical chain reactions.

Vitamin C is an excellent source of electrons; therefore, it can donate electrons to free radicals, such as hydroxyl and superoxide radicals, and quench their reactivity.

Large concentrations of vitamin C can be found in fruits such as oranges, grapefruits, tangerines, lemons, and limes. Vitamin C and bioflavonoids--the water-soluble substances that help to protect human capillaries--are found in the white linings of these and other plants.

Many vegetables also contain vitamin C, including tomatoes, broccoli, green and red bell peppers, raw lettuce, and other leafy greens. Studies suggest that vitamin C's antioxidant mechanisms may help to prevent cancer in several ways.

For example, vitamin C combats the peroxidation of lipids, which has been linked to degeneration and aging. The recommended daily allowance of vitamin C is mg. Each form has its own biological activity, which is the measure of potency or functional use in the body.

Alpha-tocopherol is the most active form of vitamin E in humans. It is also a powerful biological antioxidant. Vitamin E supplements are usually sold as alpha-tocopheryl acetate, a form that protects its ability to function as an antioxidant. The synthetic form is labeled "D, L" while the natural form is labeled "D.

Studies are under way to determine whether vitamin E, through its ability to limit production of free radicals, might help prevent or delay the development of some chronic diseases such as cardiac diseases. Vitamin E has also been shown to play a role in immune function, DNA repair, and other metabolic processes.

Selenium is used by our bodies to produce glutathione peroxidase, a component of the body's natural antioxidant defense system that is manufactured in the liver. It works with vitamin E to protect cell membranes from damage caused by harmful free radicals and helps to detoxify harmful compounds in the liver.

Additionally, some glutathione is released into the bloodstream, where it helps to maintain the integrity of red blood cells while protecting immune system white blood cells as part of the body's defense.

Eighteen patients received no supplementation, 14 patients received oral selenium, and 13 patients received oral beta-carotene for a period of one year. Between three and six months, glutathione activity increased significantly in patients treated with selenium, compared with those treated with placebo.

Only a slight increase was found following treatment with beta-carotene. The researchers stated that because glutathione plays an important role in the natural enzymatic defense system in detoxifying hydrogen peroxide in water, selenium supplementation could be of great interest in protecting cells against oxidative stress.

Because of the risk of toxic levels of selenium building up in the system, patients should avoid taking high doses mcg or more at one time, or mcg daily for an extended period of time.

Patients must also be aware of the amount of selenium they take in from seafood, whole grains, oats, and nuts. Most of these antioxidants are affordable and readily available to anyone who wants them.

Research indicates promising results on the protective effects of antioxidants to strengthen the immune system to fight toxins in human body. Pharmacists are in an exceptional position to explain proper dosages to their patients and to clarify the roles of various synthetic and natural antioxidants available on the market.

They can also explain the benefits patients receive from scavenging free radicals in their bodies to reduce cell and tissue damage.

Di Mascio P, Kaiser S, Sies H. Lycopene as the most efficient biological carotenoid singlet oxygen quencher. Arch Biochem Biophys.

Saljoughian M. Lycopene: nature's powerful antioxidant. UC Berkeley wellness letter. Co-Enzyme Q May Smith AR, Shenvi SV, Widlansky M, et al. Lipoic acid as a potential therapy for chronic diseases associated with oxidative stress.

Curr Med Chem. Packer L, Witt EH, Tritschler HJ. Alpha-lipoic acid as a biological antioxidant. Free Radic Biol Med. Whiteman M, Tritschler H, Halliwell B. Protection against peroxynitrite-dependent tyrosine nitration and alpha 1-antiproteinase inactivation by oxidized and reduced lipoic acid.

FEBS Lett. Pantuck AJ, Leppert JT, Zomorodian N, et al. This discount no longer applies if you unsubscribe from our newsletters. Français Deutsch Español Italiano Nederlands Português. Log in. Anti-ageing Advice The 7 most powerful antioxidants Antioxidants have been very popular for several years because of their ability, real or perceived, to help fight against ageing.

But which of them offers the greatest potency? Discover the 7 most effective antioxidants for health, and where to find them. Rédaction Supersmart. publication: Comments 1. Glutathione A pseudopeptide composed of three amino acids glycine, cysteine and glutamate , glutathione is produced naturally by the liver and is therefore found throughout the body.

Astaxanthin The most powerful carotenoid naturally present in a wide range of fish and seafood such as salmon, trout, shrimps, as well as plankton and krill, astaxanthin is a red-orange pigment produced mainly by algae. Riboflavin is resent in many foods including dairy products , and according to European health authorities, plays a role in 3 : normal energy metabolism; normal nervous system function; healthy skin and mucous membranes; normal vision; normal red blood cells; normal iron metabolism; reducing fatigue ; protecting cells against free radicals antioxidant effect.

Selenium Selenium is present in soil to varying degrees depending on the region, and is therefore found at differing levels in the food chain as a whole. Selenium is a powerful antioxidant which, according to the EFSA, supports 4 : normal sperm production; healthy hair and nails; normal immune system function; normal thyroid function; protection of cells against free radicals antioxidant effect.

Vitamin C Ascorbic acid or vitamin C is undoubtedly the best-known of all the antioxidant vitamins. According to the EFSA, vitamin C plays a role in 5 : normal collagen production necessary for the healthy function of blood vessels, bones, cartilage, skin, teeth and gums; normal energy metabolism; normal nervous system function; normal mental function; normal immune system function reducing fatigue ; regenerating vitamin E in its reduced form digestive absorption of iron protection of cells against free radicals antioxidant effect.

Vitamin E Present at high levels in plant oils and thus in oilseeds , vitamin E naturally occurs in eight different forms, the best-known and most powerful of which is alpha-tocopherol. Zinc Last but not least, zinc is a trace-element essential both for the activity of many enzymes in the body, as well as for growth, the immune system, skin renewal , hair renewal, etc.

European health authorities have noted that zinc contributes to: normal DNA synthesis; normal acid-base metabolism; normal metabolism of food, of carbohydrates, fatty acids, vitamin A; protein synthesis; normal intellectual functioning; normal fertility and reproduction; maintaining healthy skin, hair and nails; normal vision; maintaining healthy bones; normal immune system function; cell division; protecting cells against free radicals antioxidant effect 7.

Share Facebook Twitter Pinterest. Comments You must be connected to your account to leave a comment. Vogelberg J. Selenium is beneficial and also has some cancer preventing effect on animals, but in case of overdosing selenium significantly increases the risk of cataract development.

Our selection of articles. Anti-ageing: which foods should you eat to activate telomerase? Anti-ageing: what can you do to slow down skin ageing? Erectile problems: 10 natural and effective remedies. Anti-ageing: senolytics, the best way to stay young. Oxidative stress: symptoms, causes and protection.

Products which must be of interest Senolytic Complex Senolytics: a revolutionary formula for destroying the senescent cells responsible for aging Mitochondrial Formula Rejuvenates senescent cells by generating new mitochondria AMPK Booster The cellular enzyme that promotes longevity and reduces fat storage