How much do you know about antioxidants? If you’re like most people, you can name vitamin C and a few others. Plus, you likely know they fight free radicals. Beyond that, it’s all rather vague.
You don’t need a thorough mastery of the subject to reap the many health benefits of antioxidants. You do, however, need a basic understanding of what antioxidants do for the body so you won’t fall for the misinformation about these essential nutrients.
Antioxidant bashing has reached new heights, most recently with the CDC’s bum advice discouraging vitamin C and other supplements for immune support. As a longtime champion of antioxidants, I want to set the record straight.
Free Radicals—the Good & the Bad
Simply put, antioxidants are compounds that inactivate free radicals.
Free radicals are molecules or atoms with an unpaired electron. This makes them extremely unstable and reactive, so they seek out other electrons to pair up with. In the process, they steal electrons from (oxidize) other atoms or molecules, making them unstable and activating a chain reaction of oxidation and free radical production.
Free radicals are formed in your body during a number of biochemical reactions, most notably the production of energy (ATP) in the mitochondria of your cells. These free radicals, which are derived from oxygen, are called reactive oxygen species (ROS).
ROS and other free radicals are not always harmful. Your immune system harnesses them to kill bacteria and viruses, and they are involved in cell signaling. Furthermore, your body has an elaborate and powerful antioxidant system for neutralizing and curbing their activity.
If your antioxidant defenses cannot keep up, however, free radicals are bad news. Unchecked by antioxidants, they go on a rampage of destruction. This may be due to a shortage of antioxidants or an accumulation of oxidative damage that occurs as we age. Environmental pollutants, cigarette smoke, UV radiation, toxins, poor diet, infections, injuries, and chronic diseases also accelerate the production of free radicals—and deplete your antioxidant stores due to excessive oxidative damage that accumulates with age or to a shortage of antioxidants.
Dangers of Oxidative Stress
Whatever the reason, when your body’s antioxidant defenses and repair systems are overpowered by free radicals, the result is oxidative stress. Oxidative stress damages cells, tissues, and organs throughout your body and is a primary driver of many common health challenges:
- Immune dysfunction: It impairs the immune response and is implicated in the overwhelming inflammation that damages the lungs and endangers the lives of people with severe viral respiratory infections.
- Cardiovascular disease: Oxidized LDL cholesterol is a chief component of arterial plaque. Oxidative stress also plays a central role in heart attack and stroke damage.
- Diabetic complications: Oxidative damage to the nerves and blood vessels can lead to neuropathy, retinopathy, and other complications of diabetes.
- Cancer: Free radical-induced DNA mutations are associated with cancer.
- Autoimmune diseases: Unbridled oxidative stress stimulates chronic inflammation in rheumatoid arthritis, multiple sclerosis, and other inflammatory conditions.
- Neurodegenerative diseases: The brain’s high energy requirements make it vulnerable to oxidative stress, which is a contributor to Alzheimer's, Parkinson’s, and other neurodegenerative disorders.
I could go on and on, but you get the picture. Oxidative stress contributes to most chronic diseases—and to aging itself.
Why You Need an Antioxidant Support Team
Antioxidants are your body’s frontline defense against oxidative stress. Whether they are enzymes such as superoxide dismutase (SOD), catalase, and glutathione peroxidase produced in your body; compounds in produce and other foods; or specific nutritional supplements, antioxidants stop the vicious cycle of oxidation by giving up electrons to stabilize free radicals.
Some antioxidants like vitamin C have an affinity for water-soluble tissues, while others such as vitamin E tackle lipid peroxidation (oxidation of fats in cell membranes). Regardless of their specialty, antioxidants work as a team. Quenching a free radical makes an antioxidant momentarily unstable—but it is rapidly regenerated by other antioxidants. For example, vitamin E is reactivated by vitamin C and glutathione, and vitamin E recharges vitamin A.
These unique functions and interrelated networks underscore the importance of getting not just one antioxidant—but a whole range—which is something science has proven as well.
Studies consistently show excellent therapeutic effects of a diet rich in fruits and vegetables, which contain a wide variety of antioxidants. Meanwhile, clinical trials of a single antioxidant supplement are inconsistent—and this is why antioxidants have unfairly earned their “bad reputation.”
The Best Sources of Antioxidants
What foods have antioxidants? Virtually all living things, plants, animals, and even bacteria, have antioxidant defenses, but plants are a particularly abundant source. Berries, leafy greens, brightly colored fruits and vegetables, cruciferous vegetables, citrus, peppers, nuts, seeds, legumes, green tea, coffee, and dark chocolate are brimming with antioxidants.
As you can see, a healthy diet is a cornucopia of antioxidants. Problem is, a large government-sponsored survey, “What We Eat In America,” reports that 75% of children and adults don’t get the recommended daily intake of fruit, and 80% fail to eat enough vegetables. That’s why I also recommend taking a multivitamin with adequate levels of all the major antioxidant vitamins and minerals.
The most popular antioxidant supplements are vitamins A, C, and E, beta-carotene, zinc, and selenium, and they are included in most multivitamins. Alpha lipoic acid and coenzyme Q10 are also quite adept at quenching free radicals. Plus, many plant-based compounds with potent antioxidant activity—carotenoids (lutein, lycopene), flavonoids (catechins, resveratrol), and curcumin, to name a few—are available in supplement form.
Remember, these nutrients are no one-hit wonders. Each has many other vital, health-enhancing functions in addition to their antioxidant properties.
Antioxidants for Specific Health Challenges
Research supports the protective effects of antioxidants for the conditions related to oxidative stress discussed above—but there’s more. Here are a few additional proven benefits of dietary and supplemental antioxidants:
- Diabetes: A 2020 study published in the BMJ found that women with the highest fruit and vegetable intake and blood levels of vitamin C and carotenoids had a 50% lower risk of developing diabetes.
- Vision: Large clinical trials confirm antioxidants’ benefits for protecting against advanced macular degeneration. The best antioxidants for eyes include vitamins C and E, lutein, zeaxanthin, and zinc.
- Skin: Oral and topical antioxidants, especially vitamins A, C, and E and carotenoids, benefit the skin by quenching UV radiation-induced free radicals.
- Energy: Free radicals are a byproduct of energy production, so your ATP-generating mitochondria are hit hard. Because coenzyme Q10 is required for energy production—and is a potent antioxidant—it protects the mitochondria and boosts energy.
- Memory: Although the effects of antioxidants on memory improvement are unclear, vitamin C, coenzyme Q10, resveratrol, and curcumin have been shown to protect the brain and may slow cognitive decline.
A Cornerstone of Health
I’m the first to admit that some of the claims (antioxidants help you lose weight, antioxidants for erectile dysfunction, etc.) are over the top. Antioxidants are not a magic bullet—there is no such thing.
They do, however, serve an indispensable function, and higher levels have multiple health benefits. In my book, that’s reason enough to make an antioxidant-rich diet and supplement program a cornerstone of your daily regimen.