Antioxidants: Health Benefits, Types and Food Sources

Antioxidants are molecules that are capable of slowing down or preventing oxidation. Oxidation is a chemical reaction in which electrons are transferred from one molecule to another, or from an atom to an electron.

Oxidative stress has been linked to heart disease, cancer, arthritis, stroke, respiratory diseases, immune deficiency, emphysema, Parkinson’s disease and other inflammatory or ischemic conditions

Antioxidants are substances that protect the body from damage caused by free radicals. Free radicals are unstable molecules that can cause cell damage in the body. Antioxidants protect cells from free radical damage by donating an electron to them and stopping them from reacting with other cells. The human body is constantly exposed to free radicals and so it needs antioxidants to stay healthy.

Factors that increase the production of free radicals in the body can be internal, such as inflammation, or external, for example, pollution, UV exposure, and cigarette smoke.

Antioxidants are said to help neutralize free radicals in our bodies, and this is thought to boost overall health. They are found in many foods and supplements and can help prevent or delay some types of cell damage.

Health Benefits of Antioxidants

Antioxidants are substances that protect cells from the damage caused by free radicals. Antioxidants can help prevent diseases such as cancer, heart disease and diabetes. Antioxidants can also help with weight management and reduce the risk of developing cataracts.

  • Antioxidants may protect against certain diseases, such as heart disease and cancer.
  • Antioxidants may reduce oxidative stress.
  • Antioxidants may increase the activity of enzymes that recycle other important antioxidants in the body.
  • Some antioxidants can increase the amount of energy that people have and make them feel less tired.

Activities and processes that can lead to oxidative stress include:

Oxidative stress is a condition that occurs when the body has too many free radicals. It is the result of many different activities and processes.

  1. When there is an imbalance in the body’s antioxidant system, oxidative stress can occur from environmental factors such as pollution and tobacco smoke.
  2. The body can also produce free radicals through physical exertion, such as weightlifting or running, or even during periods of high stress.
  3. Free radicals can be produced by certain foods like red meat and processed foods containing trans fats and sugar.
  4. People who have chronic health conditions like diabetes or Parkinson’s disease are more likely to develop oxidative stress because their bodies are not able to effectively break down sugars that produce free radicals when they are metabolized in the cells of these patients.
  5. Some of the activities or exposures that can lead to oxidative stress are smoking, exposure to air pollution, exposure to radiation, and occupational hazards.
  6. Exposure to chemicals, such as pesticides and drugs, including chemotherapy.

Such activities and exposures can result in cell damage. This, in turn, may lead to:

  • An excessive release of free iron or copper ions
  • Activation of phagocytes, a type of white blood cell with a role in fighting infection
  • Increase in enzymes that generate free radicals
  • Disruption of electron transport chains

All these can result in oxidative stress. The damage caused by oxidative stress has been linked to cancer, atherosclerosis, and vision loss. It is thought that the free radicals cause changes in the cells that lead to these and possibly other conditions.

Types of antioxidants

Antioxidants are substances that prevent or reduce the effects of oxidation. Antioxidants are substances that inhibit the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons or hydrogen from a substance to an oxidizing agent.

Antioxidants can be classified as either synthetic or natural. Synthetic antioxidants are man-made compounds like butylated hydroxy anisole (BHA) and butylated hydroxytoluene (BHT). Natural antioxidants come from plant sources like grapes, blueberries and broccoli.

There are major types of antioxidants:

Flavonoids, flavones, catechins, polyphenols, and phytoestrogens are all types of antioxidants and phytonutrients, and they are all found in plant-based foods.

Each antioxidant serves a different function and is not interchangeable with another. This is why it is important to have a varied diet.

Food sources

Antioxidants are found in a wide variety of foods, but some have more than others. Foods that are particularly high in antioxidants are often referred to as a “superfood” or “functional food.” The best sources of antioxidants are plant-based foods, especially fruits and vegetables.

To obtain some specific antioxidants, try to include the following in your diet:

Vitamin A: Dairy products, eggs, and liver.

Vitamin E: Plant oils, nuts, seeds and vegetables.

Vitamin C: Citrus fruits, strawberries, broccoli, and bell peppers.

Beta-carotene: Fruits and vegetables including, carrots, pumpkin, sweet potatoes, apricots, mangos.

Lycopene: Pink and red fruits and vegetables, including tomatoes and watermelon.

Selenium: Rice, corn, wheat, and other whole grains, as well as nuts, eggs, cheese, and legumes.

Lutein: Green leafy vegetables, corn, papaya, and oranges

The following foods are good sources of antioxidants

  • Berries
  • Broccoli, spinach and other leafy greens
  • Nuts and seeds
  • Apple
  • Coffee
  • Eggplants
  • Legumes such as black beans or kidney beans
  • Black and Green teas
  • Red grapes
  • Dark chocolate
  • Pomegranates
  • Cocoa beans
  • Red wine

Tips To Add Antioxidants to Diet

The following tips could help increase your antioxidant intake:

  • Have a cup of green or matcha tea every day.
  • Include a fruit or a vegetable every time you eat, meals and snacks included.
  • Look at the colors on your plate. If your food is mostly brown or beige, the antioxidant levels are likely to be low. Add in foods with rich colors, such as kale, beets, and berries.
  • Use turmeric, cumin, oregano, ginger, clove, and cinnamon to spice up the flavor and antioxidant content of your meals.
  • Snack on nuts, seeds, especially Brazil nuts, sunflower seeds, and dried fruit, but choose those with no added sugar or salt.

There is no set recommended daily allowance (RDA) for antioxidants, but a high intake of fresh plant-based produce is considered healthful.


Antioxidants are a type of molecule that can counteract the effects of free radicals. Free radicals have been linked to a range of diseases, including cancer, heart disease, and vision loss, but this does not mean that an increased intake of antioxidants will prevent these diseases. Antioxidants from artificial sources may increase the risk of some health problems.

It is important to seek out natural sources of antioxidants, in the form of a healthful diet. Consuming fruits and vegetables has been linked to a lower rate of chronic diseases, and antioxidants may play a role. However, it is unlikely that consuming added antioxidants, especially in processed foods, will provide significant benefits.

Some antioxidants found in food sources include beta-carotene, Vitamin A, Vitamin C, Vitamin E and lycopene. Some antioxidants are made by the body and include glutathione, alpha lipoic acid and coenzyme Q10.

In addition, anyone considering taking antioxidant supplements should speak to a health provider first.