Your Complete Guide to Antioxidants: Expert Insights and Research

Written by Ahmed Zayed | Last updated on August 4, 2023

Antioxidants are molecules that protect your body from the harmful effect of free radicals which can result in certain diseases like cancers, cardiovascular, and inflammation.

Some factors that are linked to the production of free radicals include inflammation, UV rays, cigarette smoke, and pollution. 

Antioxidants neutralize the effect of free radicals by giving out their electrons. In order to keep free radicals in balance, your body has its own antioxidant defense mechanism that fights free radicals to protect your body from their harmful effects.

antioxidant foods

They are found in many fruits and vegetables. Out of all vitamins, E and C are effective antioxidants.

There is a lot of information in this article on antioxidants, their role in health and disease, and how a diet rich in antioxidants can help prevent diseases. It also discusses how natural antioxidants can boost your immune system.

Understanding How Free Radicals Work

free radical diagram showing how it forms antioxidants

In your body, free radicals play both toxic and beneficial roles.

Free radicals are continuously being formed inside your body through normal metabolic functioning. They are unstable molecules that can cause damage to your body and can result in aging. 

Free radicals are like waste substances that your body produces in response to some environmental factors. If your body cannot eliminate these waste substances from your body then oxidative stress can occur inside your body. 

This can lead to multiple health issues like heart diseases, diabetes, arthritis, and immune deficiency. 

Antioxidants play an important role in neutralizing the harmful effect of free radicals.

When free radicals and antioxidants are out of balance then oxidative stress will occur, while antioxidants and free radicals are a part of your body’s natural functioning. 

Therefore it's really important to maintain a balance between free radicals and antioxidants. 

Oxidation is an important function inside the body but when oxidative stress occurs it is harmful. 

To protect the body from oxidative stress your body has a defense mechanism that includes antioxidants and some detoxifying enzymes.

Your body uses free radicals for different functions like regulating cell growth and killing pathogens but when they are out of balance then they are harmful to your body.

Combating Oxidative Stress

Antioxidants are stable molecules that give their electrons to free radicals and try to neutralize them. 

Without antioxidants, free radicals that are highly unstable molecules can cause serious damage to your health such as vision loss, acceleration of aging, arthritis and certain cancers.

image showing how oxidative stress works

A diet high in antioxidants reduces the risk of many diseases. 

For instance, men who eat antioxidant lycopene, which is found in many fruits and vegetables such as tomatoes, watermelon, and red apricots, have a reduced risk of prostate cancer.

Antioxidants are an essential component for the survival of all living organisms. 

Cellular antioxidant glutathione is a natural antioxidant that is produced by your body while others can be found in some fruits and vegetables. Your life depends on the intake of some important antioxidants like vitamins E and C. 

Antioxidants are molecules that have the ability to reduce oxidative stress and inhibit the formation of free radicals. 

Therefore, eating a well-balanced diet with a variety of fruits and vegetables that are a rich source of antioxidants can overcome the damage of free radicals and oxidative stress.

Types of antioxidants 

There are different types of antioxidants that play an important role in your lives. 

Some essential antioxidants include:

  • Coenzyme Q10: It is a powerful antioxidant that is stored in mitochondria and is present in the heart, lungs, and kidneys in higher concentrations. Its production inside the body decreases with age but can easily be absorbed by the body if taken in food and supplement form . Spinach, soybean, broccoli , lentils, and pistachios have high concentrations of Coenzyme Q10. Coenzyme Q10 is required by your body for the growth and maintenance.

broccoli ceramic bowl
  • Vitamin C: Vitamin C is one of the best antioxidants. It is present in different fruits and vegetables.

    It plays an important role in boosting immunity, neutralizing free radicals and increasing iron absorption. Citrus fruits, strawberries, and white potatoes are rich in vitamin C.

    In addition, Vitamin C also enhances the effect of other antioxidants like vitamin E.
fresh fruit slices vitamin c
  • Vitamin E: Vitamin E is a fat-soluble vitamin that plays an important role in the protection of your cell membrane against oxidative stress.

    It is present in foods like olives, sunflower, canola, corn, carrot and spinach. It is also present in nuts like peanuts, almonds and hazelnuts.
  • Carotenoids: Carotenoids are converted into vitamin A when consumed. Carotenoids are responsible for the yellow, orange, and red pigments in different plants.

    Some fruits and vegetables that include carotenoids include Apricots, beets, broccoli, carrots, mangos, oranges, peaches, grapefruit, and watermelon.

    Carotenoids contribute to some therapeutic effects also such as anti-diabetic, anti-cancer, and anti-inflammatory.
watermelon slices
  • Vitamin A: Vitamin A is a fat-soluble vitamin. An antioxidant that plays an important role in your body. It helps to maintain your skin,your teeth and promotes good eyesight.

    The most common type of vitamin A is beta-carotene. Beta-carotene protects your body from harmful effects of free radicals. Sources of Vitamin A include carrots, milk, liver, and egg yolk.

Benefits of Antioxidants

Antioxidants are also called free radical scavengers as they protect the cells and tissues of your body from the harmful effects of these free radicals.

Protection against chronic diseases

Vitamin E is a powerful antioxidant that protects your cell from excessive cell damage which otherwise can result in different chronic diseases like cancer and heart diseases. 

Antioxidants also play an essential role in certain neurodegenerative diseases that are linked to aging and are caused by oxidative stress. 

Antioxidant phytochemicals that are naturally occurring compounds in fruits and vegetables also help to neutralize free radicals and are also responsible for the prevention of many chronic diseases. 

Therefore, fruits and vegetables rich in antioxidants can lower the risk of chronic oxidative stress-related diseases like cancer, heart disease, and cell death.

Boosting immune system

Antioxidants play an important role in boosting your immune system. The immune system protects your body from foreign bacteria and helps prevent your body against many diseases. 

As your body is continuously exposed to the harmful effects of pollution, smoke, radiation, and processed food, which produce free radicals. 

These free radicals in excessive amounts cause oxidative stress inside your body which can weaken your immune system as a result of which they lack their ability to fight against foreign bacteria. 

Therefore incorporating antioxidants in your diet can boost your immune system, for example, vitamin D, Vitamin C, Vitamin E, and zinc are powerful antioxidants that can kick-start your immune system.

Anti-aging properties 

anti aging

Antioxidants that are found in many foods are potent protective compounds. They provide many benefits to your body ranging from antiaging to prevention of cancer. Therefore a diet that has plenty of antioxidants is important for antiaging. 

Due to exposure to UV rays, accumulation of reactive oxygen species can occur which can result in wrinkles, skin damage, and atypical pigmentation. Therefore antioxidants can protect your skin from the harmful effect of reactive oxygen species.

Cognitive Function and mental health

Antioxidants are very important for your brain health as your brain is highly susceptible to the damage caused by oxidative stress, which can result in age-related cognitive decline and can affect your mental health. 

Therefore a diet rich in antioxidants is very important for mental health-related issues like depression and certain mood disorders. 

Omega-3 fatty acids are powerful antioxidants that are very beneficial for cognitive decline and mental health and are normally found in fish and walnuts.

Examples of Bioactive Antioxidants and Their Health Benefits

Bioactive compounds are the type of chemicals found in certain plants that help promote good health and also protect your body against certain diseases. 

Bioactive compounds with antioxidant activity include vitamins such as vitamin A, vitamin C and vitamin E, carotenoids, omega 3 fatty acids and flavonoids. 

These bioactive antioxidants play an interesting role in health and disease. 

  • Flavonoids: Flavonoids are rich in antioxidants that help prevent certain diseases like cardiovascular, Alzheimer's disease, dementia and certain cancers.

    Flavonoids also protect your bodies against the harmful effect of free radicals. Some foods that contain flavonoids contain onions, berries, tomatoes, and broccoli.
  • Polyphenols: Polyphenols are bioactive compounds with antioxidant properties. Polyphenols have many health benefits.

    They help in maintaining your blood sugar levels lowering the risk of diabetes, they also improve heart health by lowering blood pressure and cholesterol levels in your body.

    Foods that are rich in Polyphenols include apples, apricots, blueberries, grapes, lemon, spinach, black beans, carrots, and potatoes.
  • Fatty acids: Fatty acids also act as an important antioxidant. They have an essential role in the immune system where they are required for its proper functioning. For instance, omega 3 is an important fatty acid that plays an essential role in inflammatory processes.

Antioxidants in food

  • Allium sulfur compounds: Allium sulfur compounds protect your body against harmful effects of free radicals. Allium sulfur plays an important role in preventing the formation of blood clots.

    They also boost your immune system and have anti-aging properties. These are naturally found in leeks, onions, and garlic.
  • Lycopene: Lycopene, a potent antioxidant has been shown to be associated with a decreased risk of many diseases such as prostate cancer, cardiovascular disease and promotes good oral and bone health. Lycopene is found in tomatoes, watermelon, grapefruit, and apricots.
  • Beta-carotene: Beta-carotene protects your body by fighting against the free radicals. It is found in carrots, spinach, mangoes, apricots, and pumpkin. 
  • Zinc: Zinc plays an important part in protecting your bodies against certain diseases. They decrease the incidence of infections and have anti-inflammatory and antioxidant properties. Zinc is found in seafood, milk, and nuts.

Antioxidant supplements

Pros of antioxidant supplements

Antioxidant supplements are actually the concentrated form of naturally occurring antioxidants.

These concentrated forms of antioxidants help protect your body against the damage caused by free radicals which in high amounts can result in damage to the cells and tissues of your body and can cause some serious diseases.

Free radicals also affect our ability to exercise for a long time. Free radicals are the byproduct of energy metabolism. Therefore, taking antioxidants supplements can improve the performance of exercise by neutralizing the effect of free radicals.

Cons of antioxidant supplements 

Antioxidant supplements at relatively high doses can result in harmful effects on human health.

For instance, beta-carotene at high concentrations can result in an increased risk of lung cancer in people who smoke.

Whereas a relatively high dose of vitamin E can result in hemorrhagic shock that causes bleeding from the brain. 

Moreover, antioxidants also have the ability to interact with other medicines as well. For instance, they can increase the risk of bleeding in people who are on anticoagulants. 

High doses of Antioxidant supplements can also result in skin discoloration and some gastrointestinal problems as well. 

Choosing the Right Antioxidant Supplement 

Always try to look for supplements that are made from truly plant-based sources. Avoid taking supplements that contain preservatives and other food coloring agents that can be harmful to your health.

Read the product label to look for the ingredients and other preservatives. 

In order to choose an antioxidant supplement for your skincare then pick it according to your skin type. For instance, if you have sensitive skin then avoid using vitamin C and if you have dry skin then look for antioxidants that have hydrating power like vitamin E.

Frequently Asked Questions

What do antioxidants do for your body?

Antioxidants play an important role to protect your body from the harmful effect of free radicals. These free radicals in high concentrations can result in certain diseases like cancer, cardiovascular diseases, and neurodegenerative diseases. Antioxidants boost your overall health.

What are the best antioxidants? 

The best antioxidants are the ones that serve to protect your bodies from the harmful effects of free radicals and protect your body from heart diseases, and cancer.

They support disease prevention, improve eye health, and aid in brain functioning.

What are the three main antioxidants?

There are many different types of antioxidants that serve to protect your body. But The three main antioxidants comprise vitamin C, vitamin E, and beta-carotene. 

Can you get too many antioxidants?

No, you cannot take too many antioxidants as they can cause harm and even increase the risk of cancer. 

For instance, taking too much beta-carotene can result in an increased risk of lung cancer in smokers whereas taking too much vitamin E and lycopene can cause an increased risk of prostate cancer.

What are antioxidant foods?

Fruits and vegetables are the best sources of antioxidants. Some foods that are rich in antioxidants include blueberries, apples, apricot, black beans, kidney beans, and legumes.

Can antioxidants help with weight loss? 

Eating a diet high in antioxidants can help reduce your weight by reducing the oxidative stress caused by free radicals.

Some fruits and vegetables such as berries, nuts, and vegetable juice can help promote weight loss when consumed in daily routine.


Antioxidants can slow down the damage caused by free radicals, free radicals are molecules that are produced by your body in response to environmental and other pressure. These free radicals can also increase the risk of various health problems.

Free radicals are neutralized by antioxidants and this can boost your overall health. Therefore it is important to incorporate antioxidants into your lifestyle and diet as they play a major role in the prevention of many diseases and can boost your immune system. 


  1. Physiological role of antioxidants in the immune system. Retrieved from
  2. Antioxidant vitamins and their effect on immune system. Retrieved from
  3. Antioxidants may help patients with depression and anxiety. Retrieved from

About the author 

Dr Ahmed Zayed is a medical resident specializing in plastic surgery with years of experience in the field. He is also a writer for top-rated websites including Washington Post, Chicago Tribune, ConsumerHealthDigest, and Huffington Post

You may also like