What Are Free Radicals?

Mon Feb 28, 2022

What Are Free Radicals?

Free radicals are molecules with one or more unpaired electrons. They are a part of our normal metabolic process and are neutralized by antioxidants which donate an electron, making the molecule stable again. However, when oxidative stress occurs, there is an imbalance of free radicals to antioxidants, leading to unstable cells.1

Acute vs. chronic inflammation

Oxidative stress is caused by several factors, some of which are a part of living like breathing oxygen and burning fuel for energy— but others that are influenced by our lifestyle and external factors. These include:

  • Stress
  • Illness
  • Injury
  • Processed foods
  • Smoking
  • Alcohol
  • Environmental factors (ozone, pollution, radiation)

As explained by Khansari, when our bodies have overproduced free radicals, they react with fatty acids and proteins and impair their function. The free radicals also lead to DNA damage and mutation —this predisposes one to developing cancer, as well as a variety of chronic diseases.2

Relationship Between Oxidative Stress and Inflammation

Oxidative stress is a part of our body’s normal process. There is exercise induced oxidative stress, which is considered temporary and is a good thing for the body! The issue is when there is a build-up of long-term oxidative stress caused by the other factors listed earlier.

Relationship between oxidative stress and inflammation

When free radicals build up in the body, they cause damage to healthy cells and lead to inflammation. This inflammatory response then produces more free radicals, causing more oxidative stress, creating a vicious cycle for the body and resulting in chronic inflammation.1

Acute Vs. Chronic Inflammation

Chronic inflammation is different from acute inflammation. 

Acute inflammation is your body’s response to body damage, such as a cut on your finger. Your body sends inflammatory cells to the site of the injury. Chronic inflammation is when your body sends inflammatory cells when there is no external danger to the body.3

Chronic inflammation can be responsible for a long list of diseases including cancer, cardiovascular disease, autoimmune disorders, bone and joint disease, neurological diseases, metabolic disorders and more.

Oxidative Stress Contributes Neurological Diseases

Oxidative stress and chronic inflammation may contribute to neurological conditions including Alzheimer’s Disease, Parkinson’s Disease and Multiple Sclerosis.1

Since the brain consumes 20% of the body’s oxygen, if there is not enough available, proper function and activity will be jeopardized.4

Chronic Inflammation Causes Disease

The negative cycle of oxidative stress and chronic inflammation can cause several other conditions to occur in the human body. These include:

  • Cancer5
  • COPD6
  • Asthma7
  • Rheumatoid Arthritis8
  • Osteoporosis9
  • Osteoarthritis10
  • Diabetes1
  • Non-Alcoholic Fatty Liver Disease12
  • Atherosclerosis13
  • Heart Failure14
  • Stroke15
  • Hypertension16
  • IBD17
  • Crohn’s Disease18
  • Colitis19
  • Lupus20
  • Multiple Sclerosis21

How to Prevent Oxidative Stress

The key to reducing oxidative stress is limiting your exposure to free radicals and increasing your antioxidants. By doing so, you reduce chronic inflammation in your body which we know can cause the pathogenies of the health conditions previously listed. For example, changing your diet to include less processed food and more plants sources (fruits and vegetables) will decrease the free radicals in your body while adding more antioxidants.

antioxidants vs free radicals

Sources of Antioxidants

Antioxidants are found in plant foods including fruits, vegetables, nuts, wholegrains and some meat, poultry and fish.22

Antioxidant-Rich foods22

  • Vegetables
  • Fruit
  • Whole grain foods
  • Legumes
  • Beans
  • Lean meat and poultry
  • Fish
  • Eggs
  • Tofu
  • Nuts and seeds

WebMD explains three of the major antioxidant vitamins are beta-carotene and other carotenoids like lutein, zeaxanthin and astaxanthin, vitamin C and vitamin E. There are several food sources for each type of antioxidant including everything from berries and broccoli to collard greens and sweet potato. 

While there are various foods to get these antioxidants in, you may find that you struggle to eat them daily. There are a variety of antioxidant supplements available which can help you add more antioxidants into your body.

Tip the Scale in Your Favor

Ultimately, the best way to prevent the development of chronic disease caused by oxidative stress is to reduce free radicals in your body and add more antioxidants. This will help put a stop to the cycle of inflammatory response and provide other anti-aging properties.


1 Medical News Today

2 Tehran University of Medical Sciences

3 Cleveland Clinic

4 Redox Biology

5 Free Radical Biology and Medicine

6 Rahman

7 Allergy, Asthma & Immunology Research

8 BioMed Research International

9 Journal of Bone & Joint Surgery

10 Medicine & Pharmacy Reports

11 Circulation Research

12 Nutrients, Volume 11, Issue 4

13 Current Atherosclerosis Reports, 2017

14 American Journal of Physiology - Heart and Circulatory Physiology

15 International Journal of Stroke

16 AHA Journals

17 Oxidative Medicine and Cellular Longevity

18 World Journal of Gastroenterology

19 Indian Journal of Medical Research

20 Nature Reviews Rheumatology

21 Experimental Neurology, Volume 277

22 Better Health


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