Understanding Oxidative Stress And How It Affects Our Body

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

Introduction to oxidative stress

When researchers talk about oxidative stress, they often use an interesting analogy ‘seesaw’ for it. On one side of the seesaw are molecules called reactive oxygen species (ROS) while on the other side are antioxidants.  

Oxidative stress is the imbalance between these two in your body is called oxidative stress. It destroys various tissues and organs resulting in various diseases.

Good news is you can easily maintain this balance by living a healthy lifestyle.

Causes of oxidative stress

As we know that oxidation is a normal process that happens in our bodies. On the other hand, oxidative stress happens when there is some sort of imbalance between antioxidants and free radicals

image showing how oxidative stress works

Accurate balance of free radicals in our body is important because when they are functioning properly they help fight pathogens. If pathogens are not eliminated at the right time they cause infections. 

Free radicals can naturally occur as a result of breathing, digestion, or when your body converts food into energy.

This is appropriate and beneficial. The free radical formation can also be accelerated by other exposures and lifestyle choices such as:

  • Ultraviolet rays produced by the sun or tanning beds
  • Second-hand smoke and cigarette smoking
  • Alcohol
  • Pollutants
  • Pesticides, medications, and chemicals
  • Insufficient or excessive exercise (overtraining)
  • Consuming a lot of sugar or fat 

Oxidative stress is a result of an imbalance between the production of free radicals and the cell's capacity to eliminate them.

For example, an overabundance of peroxynitrite and hydroxyl radicals can lead to lipid peroxidation, which harms lipoproteins and cell membranes. 

What are free radicals?

A free radical is any molecular species with an unpaired electron in its atomic orbital which is capable of existing on its own.

Most radicals exhibit certain similar characteristics when an unpaired electron is present. It is important to note that many radicals are highly reactive and unstable in nature.

free radical diagram showing how it forms antioxidants

A vast variety of molecular species, including lipids, proteins, and nucleic acids, are often destroyed by oxidative stress. This develops as a result of an imbalance between free radical generation and antioxidant defenses.

According to research, cells that have been harmed by free radicals suffer from pathogenic age-related alterations.

Along with the aging process itself, an increasing number of illnesses or ailments also take place.

Have a look at our blog to know more about the 12 hallmarks of aging. 

Sources of free radicals

Free radicals and other reactive oxygen species (ROS) are produced by the body’s regular, vital metabolic activities or by external factors such as exposure to X-rays, ozone, tobacco smoke, air pollution, and industrial toxins. 

Either internal or external factors can generate ROS.

Internal producers of ROS are various cellular organelles, for example, mitochondria, peroxisomes, and endoplasmic reticulum, where substantial oxygen consumption takes place.

Role of Antioxidants

Have you heard the word “antioxidant”? You might have read it on the back of your orange juice carton you picked up last week or maybe on that supplement bottle, you took this morning.

Most people only know that antioxidants are healthy, many don’t have any idea what they actually do.

Read on to learn more about this nutrition buzzword.

What are antioxidants?

foods with antioxidants

Antioxidants are human-made or naturally occurring substances that protect us against oxidative stress.

Years of research suggest that antioxidants offer defense against free radical damage, which is a major factor in the development of many chronic diseases. 

How is oxidative stress reduced?

Antioxidants can get rid of harmful reactive oxygen molecules (ROS) in the body. They also stop proteins from changing their shape and keep cancer from happening because of oxidative stress.

Due to the possibility of genetic damage caused by oxidative products, B-carotene's antioxidant properties may offer protection against cancer.

B-carotene's photoprotective qualities may therefore guard against UV light-induced cancer. B-carotene's immune strengthening may help prevent cancer.

By changing how carcinogens are metabolized by the liver, b-carotene also has anti-carcinogenic effects.

It’s important to note that while antioxidants can help to reduce oxidative stress, they are not a cure-all for all health problems.

As always it’s very important to maintain a balanced diet and healthy lifestyle to promote overall health and well-being.

Sources of Antioxidants in the Diet

You can lower your risk of developing certain diseases by consuming an antioxidant-rich diet that increases blood antioxidant levels. Here are some excellent suggestions:

Dark Chocolate: Dark chocolate contains more minerals and antioxidants than conventional chocolate, as it has more cocoa. It has phytonutrients called flavonoids, which are plant chemicals acting as antioxidants.

dark chocolate

Additionally, the antioxidants in cocoa and dark chocolate have been linked to several remarkable health advantages, including a decline in inflammation and a reduction in heart disease risk factors.

Did you know dark chocolate may lower the risk of heart disease by increasing your blood antioxidant levels and reducing the oxidation of LDL (bad) cholesterol?

Pecans: The antioxidant levels in the blood can be increased by taking them regularly. For instance, a study revealed that people at risk of heart disease who consumed pecans every day for eight weeks saw a rise in blood antioxidant levels. Pecans contain tocopherols that provide antioxidants to the body.  

Blueberries: Among popular fruit varieties, blueberries have one of the most significant antioxidant capabilities.


It helps in lowering inflammation and changing how some genes are expressed.

Additionally, it has been demonstrated that the antioxidants in blueberries, particularly a variety known as anthocyanins, lower blood pressure, and LDL cholesterol levels. The Two biggest risk factors for heart disease. 

Artichokes: Numerous minerals and antioxidants are found in artichokes, and how they are prepared might affect how much of an antioxidant they contain.

In one interesting study, trusted Source, the antioxidant levels were compared after boiling, frying, and steaming.


According to the findings, boiling enhanced antioxidant effectiveness eight times while steaming increased it by fifteen. Boiling and steaming weaken the cell walls make the antioxidants more readily available. 

Strawberries: The antioxidants, vitamins, and minerals in strawberries are abundant. The antioxidant compounds called anthocyanins are responsible for the red color of strawberries. Anthocyanins in strawberries promote bone health and keep the digestive system healthy.

Red cabbage: Numerous minerals, including vitamins A, C, and K, as well as many antioxidants, are present in red cabbage. Anthocyanins are present in red cabbage, red kale, and strawberries.

These antioxidants not only give the vegetable its red color but also support heart health, fight cancer, and lessen inflammation.

Beetroot: Vegetables like beets include betalains, a kind of antioxidant that is pigmented. Betalains may aid in the prevention of digestive problems and colon cancer.

Beetroot also helps in cognitive function and glucose metabolism in our bodies.

Spinach: One of the vegetables with the highest nutritional content is leafy green spinach. It has many vitamins, minerals, and antioxidants with a super low-calorie count.

Spinach has an abundance of Lutein and zeaxanthin, two antioxidants that may help shield your eyes from harmful UV light and other light wavelengths

These antioxidants assist in preventing long-term eye damage that free radicals may cause. 

Beans: Kaempferol is a specific antioxidant found in beans. Significant health advantages of this antioxidant include decreased chronic inflammation and reduced cancer growth.

For instance, kaempferol may inhibit the formation of malignancies in the breast, bladder, kidneys, and lungs, according to some animal studies. 

Contribution of Oxidative Stress on Chronic Diseases

As we already know how oxidative stress takes place. Therefore we know that excess oxidants can harm cells, tissues, and organs if the antioxidant defenses are overwhelmed.

Oxidative stress can harm DNA, proteins, and cells, speeding up the aging process.

Numerous medical disorders, such as diabetes, cancer, and neurological illnesses like Alzheimer’s, may also be impacted along the way.

Chronic inflammation can be triggered by oxidative stress. The body’s immune system is triggered by infections and trauma. Immune cells, called macrophages, produce free radicals as they fight off invasive microbes. Inflammation can result from these free radicals damaging healthy cells. 

Diagnosing oxidative stress

There are numerous methods for measuring oxidative stress in our bodies. 

Direct and indirect assessment methods are common ways to measure oxidative stress. 

The indirect method is less expensive and less invasive than the direct method. They can be easily performed in clinical settings using readily available equipment and can provide a broad overview of the oxidative stress status of the body.

Direct methods, on the other hand, are more sensitive and specific in detecting ROS levels and can provide more accurate measurements.

However, direct methods are often more technically demanding and require specialized equipment and expertise to perform.

They may also be more invasive and expensive than indirect methods.

Let us have a look at a few of these below:

Direct Method

Here are some of the common direct assessment methods:

  • Chemiluminescence to measure ROS levels (most common)
  • ROS levels in white cells and platelets by flow cytometry
  • Cytochrome c reduction test
  • Nitroblue tetrazolium test

Indirect method

Some of the indirect methods are as follows:

  • Myeloperoxidase or Endtz test
  • levels of products of lipid peroxidation, protein oxidation, and DNA oxidation
  • Chemokine levels
  • Levels of antioxidants, micronutrients, and enzymes
  • Redox potential (GSH/GSSG)
  • Thiobarbituric acid assay (TBARS)

Supplementation and oxidative stress

Beyond middle age, antioxidant supplements can be beneficial and act as free radical scavengers.

It is highly recommended for anyone over thirty years of age to take their daily dose of multivitamins.

antioxidant supplements

Let's have a look at some of the supplements which help with oxidative stress.

  • Vitamin C: It is a good source of antioxidants available in fruits and vegetables. It acts as a redox buffer and neutralizes oxidative stress. It helps reduce the risks of chronic diseases and boosts immunity levels. 
  • Vitamin E: It is a fat-soluble antioxidant that prevents the formation of ROS. It is the most potent antioxidant of the lipid membrane. It prevents heart diseases, protects the skin, and treats eye disorders. 
  • Beta-carotene: It safeguards the body from free radicals as they damage the body and cause chronic diseases. 
  • Coenzyme Q10: It is an essential antioxidant, especially when it mixes with vitamin E. It promotes energy in cells and prevents blood clots. 

Also, Trace elements like selenium and zinc are supplements one must include in the diet.  

Managing oxidative stress

In today’s fast-paced world, it is nearly impossible to completely avoid being exposed to free radicals and oxidative stress. 

If you follow these 7 actions, they could lessen disorders linked to free radical cell injury and oxidative cell damage in your body:

  1. Eating foods high in natural antioxidants (at least 5 servings daily), such as Fruits including citrus, berries, cherries, tomatoes, and olives Avocados, broccoli, carrots, prunes, and dark-green leafy veggies
  2. Regular use of stress-relieving exercises like yoga and meditation.
  3. Do not use expired or rancid oil for cooking.
  4. Routine exercise.
  5. Maintain a regular sleep schedule and biological rhythm.
  6. Eat organic food that has not been treated with pesticides or chemicals.
  7. Use environmentally beneficial practices including avoiding plastics, carpooling if possible, and disposing of toxic waste safely.

Role of Oxidative Stress in Aging

The imbalance between reactive oxygen and nitrogen species synthesis with antioxidant defenses leads to oxidative stress. 

The steady loss of tissue and organ function is a feature of aging. The oxidative stress theory of aging suggests that as we age, our body accumulates damage caused by RONS (reactive oxygen and nitrogen species). 

This damage leads to declines in our body's functions over time. There is a  connection that links chronic inflammation to the development of cancer. 

The gradual decline of organ and tissue function occurs at age 17. 

The free radical theory of aging is based on the structural damage-based premise that age-associated functional losses are caused by the accumulation of oxidative damage to macromolecules.

This theory was later renamed the oxidative stress theory of aging.

Increased RONS levels likely cause cellular senescence, a physiological mechanism that prevents cellular growth in response to damage during replication. 

However, the precise mechanism of oxidative stress-induced aging is still unknown. Protein misfolding and errors also occur within cells during the impact of oxidative stress.

Frequently Asked Questions:

What are the symptoms of oxidative stress?

Oxidative stress can cause signs and symptoms like Fatigue, loss of memory, or mental fog. However joint and muscle ache is very common. With the process of aging wrinkles, white hair & declining vision are observed.

Moreover, headache, responsiveness to noise, the potential for infection, and unstable levels of blood sugar are also seen. 

How do you get rid of oxidative stress?

Here are three types of plant foods that help prevent oxidative stress and inflammation.

  • Vegetables and fruits are abundant in polyphenols.

When consumed, polyphenols work as antioxidants in the body to fend off free radicals and stop cell deterioration.

  • Terpenoids, which are included in a variety of herbs and spices, may strengthen the body’s defenses against oxidative stress.
  • Through the use of phenolic chemicals, legumes, and beans also aid the body in the battle against oxidative stress. 

Does anxiety cause oxidative stress?

YES. According to recent research, oxidative stress is linked to many psychiatric conditions, including anxiety and serious depression.

Since anxiety disorders are associated with increased oxidative stress, some people have proposed antioxidant therapy as a complementary therapy to traditional drugs. 

What vitamin stops oxidative stress?

A water-soluble antioxidant called vitamin C, which is present in the cytosol and extracellular fluid can interact directly with free radicals to stop oxidative damage. 

Vitamins E and C have been found to work better as antioxidants together than they do separately because of their varied subcellular sites. 

What happens when you have too much oxidative stress?

Numerous neurological conditions, including Parkinson’s disease, Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS), multiple sclerosis, depression, and memory loss, have been associated with oxidative stress.

Oxidative stress is associated with lung conditions like asthma and chronic obstructive pulmonary disease (COPD), which are characterized by local and systemic chronic inflammation. 


We understand that you can not completely avoid constant exposure to free radicals.

What you CAN do is, you can make better lifestyle choices regarding exercise, food, and the environment. This will keep diseases away from your body for as long as you follow them.

Antioxidants have always left a lasting influence in industries like pharmacy, food, cosmetics, and medicine.

According to the studies, since oxidative stress has so many beneficial benefits on human health, it is crucial to consume natural antioxidants regularly.

To strengthen your body’s antioxidant defenses and reduce your exposure to free radical triggers, you must adopt a holistic approach throughout all of your everyday routines.


Knudsen. M. (2021). Oxidative stress: causes, effects, prevention from https://ro.co/health-guide/oxidative-stress/

López-Otín. C. Blasco. M. Partridge. L. Serrano.M. Kroemer G. (2023) Hallmarks of aging: An expanding universe from https://pubmed.ncbi.nlm.nih.gov/36599349/#:~:text=We%20propose%20the%20following%20twelve,exhaustion%2C%20altered%20intercellular%20communication%2C%20chronic

Lobo. V Patil. A. (2010). Free radicals, antioxidants, and functional foods: Impact on human health from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3249911/

Phaniendra. A Jestadi. B. (2015). Free Radicals: Properties, Sources, Targets, and Their Implication in Various Diseases https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4310837/ 

Zehiroglu. C. (2019). The importance of antioxidants and their place in today’s scientific and technological studies from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6828919/ 

Raman. R.(2022). 12 Healthy Foods High in Antioxidants from https://www.healthline.com/nutrition/foods-high-in-antioxidants#TOC_TITLE_HDR_11

Fletcher. J.(2019). A guide to antioxidant foods from https://www.medicalnewstoday.com/articles/325873 

Eske. J.(2019). How does oxidative stress affect the body? https://www.medicalnewstoday.com/articles/324863 

Venkataraman. L.(2023). Diagnosis and Prevention of Oxidative Stress https://www.google.com/amp/s/www.medindia.net/amp/patientinfo/diagnosis-and-prevention-of-oxidative-stress.htm 

Liguori. I. Russo. G. Curcio. F. Bulli. G.(2018). Oxidative stress, aging, and diseases https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5927356/#:~:text=The%20oxidative%20stress%20theory%20of,accumulation%20of%20RONS%2Dinduced%20damages. 

Benedict. F.(2016). How to fight oxidative stress with plant food https://chopra.com/articles/how-to-fight-oxidative-stress-with-plant-foods

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