The causes of antioxidants can be natural or artificial. Some plant-based foods are thought to be rich in antioxidants. Plant-based antioxidants are a kind of phytonutrient or plant-based nutrient.

The body also creates some antioxidants, known as endogenous antioxidants. Antioxidants originated outside the body are called exogenous.

Some free radicals are waste substances produced by cells as the body processes food and reacts to the environment. If your body cannot process and eliminate free radicals, oxidative stress can result. This can harm cells and body function. Free radicals can also be known as reactive oxygen species (ROS).

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

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 said to help neutralize free radicals in our bodies, and this is thought to boost overall health.

Fruits
Fruits

Health Benefits of Antioxidants

Antioxidants can help protect against the cell damage that free radicals have caused, known as oxidative stress.

Activities and processes that can lead to oxidative stress include:

  • mitochondrial activity
  • excessive exercise
  • tissue trauma, due to inflammation and injury
  • ischemia and reperfusion damage
  • environmental pollution
  • consumption of certain foods, especially refined and processed foods, trans fats, artificial sweeteners, and certain dyes and additives
  • smoking
  • radiation
  • ozone
  • exposure to chemicals, such as pesticides and drugs, including chemotherapy
  • industrial solvents

Such activities and exposures can result in cell damage.

This may also lead to:

  • activation of phagocytes, a type of white blood cell with a role in fighting infection
  • an increase in enzymes that generate free radicals
  • a disruption of electron transport chains
  • an excessive release of free iron or copper ions

All of these can happen in oxidative stress.

The damage generated by oxidative stress has been linked to cancer, atherosclerosis, and vision loss. It is believed that free radicals cause changes in the cells that lead to these and possibly other conditions. An intake of antioxidants is believed to reduce these risks.

One study: “Antioxidants act as a radical scavenger, electron donor, hydrogen donor, peroxide decomposer, singlet oxygen quencher, an enzyme inhibitor, synergist, and metal-chelating agents.”

Additional research also indicated that antioxidant supplements may help reduce vision loss due to age-related macular degeneration in older people.

Overall, however, there is a lack of evidence that a higher intake of specific antioxidants can reduce the risk of disease. In most cases, results have tended to show no benefit or a detrimental effect, or they have been conflicting.

Types

There are assumed to be hundreds and perhaps thousands of substances that can act as antioxidants. Each has its own role and can interact with others to help the bodywork effectively.

“Antioxidant” is not really the name of a substance, but rather it describes what a range of substances can do.

Examples of antioxidants that come from outside the body include:

Flavones, flavonoids, 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

The best sources of antioxidants are plant-based foods, especially fruits and vegetables. Foods that are particularly high in antioxidants are often referred to as a “superfood” or “functional food.”

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

  • Vitamin A: Dairy produce, eggs, and liver
  • Vitamin C: Most fruits and vegetables, especially berries, oranges, and bell peppers
  • Vitamin E: Nuts and seeds, sunflower and other vegetable oils, and green, leafy vegetables
  • Beta-carotene: Brightly colored fruits and vegetables, such as carrots, peas, spinach, and mangoes
  • Lycopene: Pink and red fruits and vegetables, including tomatoes and watermelon
  • Lutein: Green, leafy vegetables, corn, papaya, and oranges
  • Selenium: Rice, corn, wheat, and other whole grains, as well as nuts, eggs, cheese, and legumes

Other foods that are believed to be good sources of antioxidants include:

  • legumes such as black beans or kidney beans
  • eggplants
  • green and black teas
  • red grapes
  • dark chocolate
  • pomegranates
  • goji berries

Goji berries and many other food products that contain antioxidants are available to purchase online.

Foods with rich, vibrant colors often contain the most antioxidants.

The following foods are good sources of antioxidants. Click on each one to find out more about their health benefits and nutritional information:

  • blueberries
  • apples
  • lentils
  • broccoli
  • spinach

Effect of cooking

Cooking particular foods can either increase or decrease antioxidant levels.

Lycopene is the antioxidant that gives tomatoes their rich red color. When tomatoes are heat-treated, the lycopene becomes more bio-available (easier for our bodies to process and use).

However, studies have shown that cauliflower, peas, and zucchini lose much of their antioxidant activity in the cooking process. Have it in mind that the important thing is eating a variety of antioxidant-rich foods, cooked and raw.

Dietary tips

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. 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.

Or, try these healthy and delicious recipes developed by registered dietitians:

Finally, a high intake of fresh plant-based produce is considered however healthful.