What Is Oxidative Stress? How to Combat It
Oxidative stress is an imbalance between free radicals (reactive oxygen species) produced inside the cell and the antioxidants in the body that neutralize them.
The final electron receptor in the electron transport chain, the energy-generating pathway in every cell’s mitochondrion, is oxygen. Approximately 4% of the oxygen species receiving electrons gain an unstable number of electrons. These highly reactive oxygen species react with structural elements in your cells, taking their electrons and changing their structure.
Oxidation is a normal process in your body. For example, a respiratory burst produces superoxide and hydrogen peroxide to kill bacteria in your cells. Other processes in the body produce reactive oxygen species for normal cell functioning and to talk to other cells.
Antioxidants are molecules that can donate an electron to a reactive oxygen species, stabilizing it without becoming unstable themselves.
When the number of free radicals produced exceeds your body’s ability to neutralize them, it is called oxidative stress.
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What is oxidative stress?
Free radicals (reactive oxygen species) are a byproduct of normal immune function and metabolism in every cell in your body. Exposure to tobacco smoke, drugs, pollution, pesticides, and ultraviolet radiation also produces free radicals.
Free radicals have an unpaired electron, which makes them highly reactive. They need another electron to become stable. Since they are so unstable, they are dangerous to cells. Hydrogen peroxide and singlet oxygen act similarly to free radicals and, therefore, are all grouped as reactive oxygen species. Reactive nitrogen species also contribute to oxidative stress.
Reactive oxygen species bind to cell proteins, lipids in cell membranes, DNA, and other cell structures, slightly altering their shape and impairing their function. When reactive oxygen species bind to:
- Lipids: Reactive oxygen species can change the shape of cell membranes, damaging their integrity.
- DNA: Reactive oxygen species can cause mutations in your genetic code, increasing the risk of cancer.
- Proteins: Reactive oxygen species can change protein’s shapes and render them nonfunctional.
Your cells can repair some damage caused by reactive oxygen species, but if the damage is too great, it will trigger a process called apoptosis (controlled cell death) or necrosis (more widespread tissue death).
To protect itself, your body produces antioxidants such as glutathione, which neutralize and eliminate free radicals by converting them to harmless substances such as oxygen gas and water.
An imbalance between the body’s capacity to use antioxidants to combat free radicals and their production is the root cause of oxidative stress.
What diseases are associated with oxidative stress?
Oxidative stress increases with age and is a risk factor for chronic diseases such as1,2
- Acute inflammation
- Alzheimer’s disease
- Amyotrophic lateral sclerosis
- Cardiovascular disease
- Chronic obstructive pulmonary disease
- Heart attacks
- Kidney disease
- Multiple sclerosis
- Parkinson’s disease
- Rheumatoid arthritis
The brain is very sensitive to oxidative stress because of its high metabolic activity, high density of oxidative substances, and relatively low oxidative defense systems.3
What is the major cause of oxidative stress?
Oxidative stress can occur naturally in your body. Lifestyle, disease, and environmental factors can increase reactive oxygen species production and cause oxidative stress. Examples include1,2
- Anticancer drugs
- Chemical solvents
- Chronic infections
- Chronic inflammation
- Excessive alcohol consumption
- Excessive exercise
- Heavy metals
- Mental stress
- Overweight and obesity
- Ultraviolet radiation
Protecting yourself from these environmental factors can reduce oxidative stress in your body and potentially slow the aging process.
How can you manage oxidative stress?
Free radicals and reactive oxygen species are essential for normal cellular function and to protect against bacterial infections. However, excessive oxidative stress can contribute to aging and diseases associated with aging.
Antioxidants donate electrons to reactive oxygen and reactive nitrogen species and can help your body manage oxidative stress. They donate an electrons to reactive oxygen species and stabilize them. Vitamins A, C, and E are examples of antioxidants.
Highly processed foods can increase oxidative stress. Choose whole foods rich in antioxidants such as beta-carotene, ubiquinone, polyphenols, flavonoids, quercetin, resveratrol, and curcumin. Examples of foods rich in these antioxidants include the following:
- Citrus fruits
- Dark, leafy greens
- Green tea
- Onion and garlic
These nutritional antioxidants scavenge free radicals, repair oxidized cell membranes, decrease reactive oxygen species production, and neutralize reactive oxygen species.4
Making the following lifestyle changes can reduce excessive oxidative stress:2,5
- Quit smoking. If you smoke
- Wear sunscreen
- Increase physical activity throughout the day
- Manage mental and emotional stress
- Limit exposure to toxins and chemicals
- Limit alcohol consumption
- Get enough sleep
Many people take antioxidant supplements to help their bodies manage oxidative stress, especially if they don’t consume a diet rich in antioxidants. Examples of antioxidant supplements include:
- Glutathione is a “master antioxidant” that is produced and consumed in every cell in your body. Glutathione is also important for healthy immune function.
- Coenzyme Q10 is an antioxidant and a mitochondrial cofactor involved in energy conversion in mitochondria.
Learn more about glutathione and other antioxidant supplements that decline with age and may contribute to aging-related diseases.
Get started today with a monthly subscription of glutathione.
- Pizzino G, Irrera N, Cucinotta M, Pallio G, Mannino F, Arcoraci V, Squadrito F, Altavilla D, Bitto A. Oxidative Stress: Harms and Benefits for Human Health. Oxid Med Cell Longev. 2017;2017:8416763. doi: 10.1155/2017/8416763. Epub 2017 Jul 27. PMID: 28819546; PMCID: PMC5551541.
- Simioni C, Zauli G, Martelli AM, Vitale M, Sacchetti G, Gonelli A, Neri LM. Oxidative stress: role of physical exercise and antioxidant nutraceuticals in adulthood and aging. Oncotarget. 2018 Mar 30;9(24):17181-17198. Doi: 10.18632/oncotarget.24729. PMID: 29682215; PMCID: PMC5908316.
- Garcia-Mesa Y, Colie S, Corpas R, Cristofol R, Comellas F, Nebreda AR, Gimenez-Llort L, Sanfeliu C. Oxidative Stress Is a Central Target for Physical Exercise Neuroprotection Against Pathological Brain Aging. J Gerontol A Biol Sci Med Sci. 2016;71:40–49.
- Berger MM. Can oxidative damage be treated nutritionally? Clin Nutr. 2005;24:172–183.