What happens to your body when you take antioxidants?

October 16, 2025 •

4 min read

According to research from the National Institutes of Health, an imbalance between free radicals and antioxidants, known as oxidative stress, has been implicated in numerous chronic diseases. So, what happens to your body when you take antioxidants? In essence, these compounds help restore balance by neutralizing unstable molecules that can cause cellular damage throughout the body.

Quick Summary

Antioxidants work by neutralizing harmful free radicals that cause oxidative stress and cellular damage. They are vital for maintaining physiological balance and are obtained from a diet rich in fruits, vegetables, and other plant-based foods. While supplements exist, food sources offer synergistic benefits and are generally safer.

Key Points

Neutralizes Free Radicals: Antioxidants donate electrons to neutralize unstable free radical molecules, stopping the chain reaction of cellular damage.
Combats Oxidative Stress: By counteracting free radicals, antioxidants help maintain the balance needed for proper physiological function and prevent oxidative stress.
Protects Against Chronic Disease: A diet rich in antioxidants is linked to a lower risk of chronic conditions like heart disease, certain cancers, and neurodegenerative disorders.
Enhances Cellular Health: They protect vital cellular components, including DNA, lipids, and proteins, from oxidative damage.
Varies by Source: Antioxidants from whole foods provide a synergistic benefit, whereas high-dose supplements can be ineffective and potentially harmful.
Supports Skin and Immune Health: Specific antioxidants like vitamins C and E protect skin from environmental damage and support a healthy immune system.
Potential Risks of Supplements: Excessive intake of isolated antioxidants, such as high-dose beta-carotene, can lead to adverse health outcomes like an increased risk of lung cancer in smokers.

The Fundamental Process: How Antioxidants Counteract Free Radicals

To understand the role of antioxidants, one must first grasp the concept of free radicals. Free radicals are highly reactive molecules with an unpaired electron, formed as natural byproducts of metabolism and from external sources like pollution, tobacco smoke, and UV radiation. Because they are unstable, they steal electrons from other healthy cells, triggering a chain reaction of damage known as oxidative stress.

When you introduce antioxidants into your body, you are providing molecules that can readily donate an electron to a free radical without becoming unstable themselves. This action neutralizes the free radical, terminating the destructive chain reaction and preventing damage to vital cellular components like lipids, proteins, and DNA. Maintaining a healthy balance between free radicals and antioxidants is critical for proper physiological function.

The Impact of Antioxidants on Different Bodily Systems

Antioxidants are not a single substance but a diverse group of compounds, each with a unique role in different parts of the body. Their collective efforts contribute to overall health and disease prevention by mitigating the damage caused by free radicals.

Cardiovascular Health: Antioxidants play a crucial role in protecting against heart disease. They prevent the oxidation of low-density lipoprotein (LDL) cholesterol, which can stick to artery walls and contribute to the formation of plaque, a key step in the development of atherosclerosis. Lycopene, found in tomatoes, is one example of an antioxidant linked to a reduced risk of cardiovascular issues.
Brain Function and Aging: Oxidative stress is thought to play a role in neurodegenerative diseases and the aging process itself. Antioxidants help protect nerve cells from damage. Lutein and zeaxanthin, for instance, are antioxidants that have been linked to improved cognitive function and a reduced risk of age-related macular degeneration.
Immune System Support: The immune system uses free radicals to fight off infections, but an excess of these compounds can be detrimental. Antioxidants, such as vitamin C, help modulate this response. Adequate intake supports the immune system's function while preventing collateral damage to healthy cells.
Skin Protection: Environmental factors like UV radiation and pollution generate free radicals that can damage skin cells, leading to premature aging and other issues. Vitamins C and E are powerful antioxidants that protect skin from this damage and support collagen production, helping maintain skin elasticity.

The Dietary Difference: Food vs. Supplements

There is a significant difference in how the body processes antioxidants from whole foods versus high-dose supplements. This has important implications for both efficacy and safety.

Natural Antioxidant Sources vs. High-Dose Supplements


Feature	Natural Food Sources	High-Dose Supplements
Antioxidant Delivery	Synergistic effect from complex mix of vitamins, minerals, fiber, and other phytochemicals.	Isolated and concentrated doses of specific antioxidants.
Health Benefits	Strongly associated with a lower risk of chronic diseases, improved overall health.	Lack strong evidence for disease prevention; some studies show conflicting or detrimental effects.
Safety Profile	Low risk of overconsumption and adverse effects. Whole foods provide a natural balance.	Potential for harmful, toxic effects and increased health risks at high doses (e.g., lung cancer in smokers taking high beta-carotene).
Bioavailability	Natural context of food matrix may enhance bioavailability and effectiveness.	Can interfere with the body's natural processes or with certain medications.

For most healthy individuals, the best strategy is to obtain antioxidants from a balanced, varied diet rich in fruits, vegetables, nuts, and whole grains.

Potential Risks of Excessive Antioxidant Intake

While antioxidants are generally beneficial, the idea that "more is better" does not apply, especially concerning supplements. High doses of isolated antioxidants can lead to unintended consequences, sometimes promoting oxidative damage rather than preventing it—a phenomenon known as the “antioxidant paradox”.

One of the most well-documented risks involves beta-carotene supplements. Studies have shown that high doses can increase the risk of lung cancer in smokers and individuals with occupational exposure to asbestos. Similarly, excessive intake of vitamin E has been linked to an increased risk of prostate cancer in some studies.

Furthermore, high-dose antioxidants can sometimes interfere with beneficial training adaptations in athletes or interact negatively with certain medications, including cancer treatments.

Conclusion: The Importance of Balance

In summary, when you take antioxidants through a balanced diet, your body benefits by strengthening its defense against oxidative stress and reducing the risk of chronic diseases. Antioxidants neutralize free radicals, protecting your cells from damage that can affect your cardiovascular system, brain, skin, and immune function. The key lies in obtaining these powerful compounds from diverse, whole food sources. Relying on high-dose supplements of isolated antioxidants can be ineffective and potentially harmful, disrupting the body’s natural equilibrium. A diet rich in a rainbow of fruits and vegetables is the most effective and safest way to harness the protective power of antioxidants for long-term health.

For more information on the role of nutrition in preventing chronic disease, see the Better Health Channel's page on antioxidants.

Frequently Asked Questions

The primary function of antioxidants is to neutralize free radicals, which are unstable molecules that can cause cellular damage, a process known as oxidative stress. By donating an electron to the free radical, the antioxidant stabilizes it and stops the chain reaction of damage.

Antioxidants can be obtained from both dietary and internal sources. Your body produces its own endogenous antioxidants, but it also relies on exogenous antioxidants from your diet, primarily found in fruits, vegetables, nuts, seeds, whole grains, and spices.

No, evidence suggests that getting antioxidants from whole foods is more beneficial. Foods contain a complex mix of nutrients and other compounds that work synergistically. High-dose supplements of isolated antioxidants have shown mixed results in studies and can sometimes be ineffective or even harmful.

Yes, excessive intake of antioxidants, particularly from high-dose supplements, can be harmful. In some cases, it can cause the antioxidant to act as a pro-oxidant, increasing oxidative damage. High doses can also interfere with the body's natural processes or interact with medications.

Oxidative stress is an imbalance between the production of free radicals and the body's ability to neutralize them. Prolonged oxidative stress can damage DNA, proteins, and lipids, contributing to chronic disease. Antioxidants help by scavenging and neutralizing excess free radicals, restoring the natural balance.

Yes, different antioxidants have unique properties and act in different areas of the body. For example, fat-soluble vitamin E protects cell membranes, while water-soluble vitamin C works in cellular fluids. Carotenoids like lutein and zeaxanthin are particularly beneficial for eye health.

Excellent sources of antioxidants include berries, dark chocolate, spinach, kale, artichokes, plums, pecans, and various herbs and spices. Colorful fruits and vegetables tend to be especially rich in these beneficial compounds.