The definition of free radicals is “uncharged molecules (typically highly reactive and short-lived) having an unpaired valence electron.” According to the Pharmacognosy Review, “reactive oxygen species and reactive nitrogen species are generated by our body by various endogenous systems, exposure to different physiochemical conditions or pathological states.” (1)
Free radicals can be very harmful, but their production within the body is certainly not abnormal or even entirely bad. Despite contributing to the aging process, free radicals are also essential players in the immune system. Our bodies produce free radicals as byproducts of cellular reactions, metabolism of foods, breathing and other vital functions. (2) The liver produces and uses free radicals for detoxification, while white blood cells send free radicals to destroy bacteria, viruses and damaged cells.
Why are free radicals thought to be dangerous then? As naturopath Dr. Stephen Byrnes explains, free radicals are unstable molecules, meaning they’re always on the lookout for chemical components that other cells have but that they themselves are missing.
Electrons exist in pairs, and free radicals are missing an electron. This is their weapon of sorts: Free radicals “react” with just about anything they come into contact with, robbing cells and compounds of one of their electrons. (3) This process makes the affected (“robbed”) cell or compound unable to function normally and turns some cells into electron-seeking muggers themselves, leading to a chain reaction in the body and the proliferation of even more free radicals. The clean-up crew, our immune system’s “soldiers,” lose their control and end up marauding and pillaging throughout the body, destroying healthy cells and tissues.
What Is “Oxidative Stress,” and How Do Antioxidants Fit In?
Free radicals ultimately harm and age the body over time because they damage DNA, cellular membranes, lipids (fats) stored within blood vessels and enzymes. Normally, free radicals — or as they’re also commonly referred to, reactive oxygen species and reactive nitrogen species — live in balance with antioxidants in the body. It’s when this balance is disturbed, due to low intake of antioxidants and accumulation of free radicals, that accelerated aging occurs.
The damage done by free radicals in the body is known as oxidation:
- Oxidation is the same process that browns an apple or rusts metal. Rampaging free radicals react with compounds in the body and oxidize them. The amount of oxidation in the body is a measure of oxidative stress.
- High levels of oxidative stress affect every organ and system in the body and have been linked with everything from Alzheimer’s disease, arteriosclerosis, cancer and heart disease to accelerated aging, asthma, diabetes and leaky gut syndrome. Oxidative stress is believed to lead to the development of the most prevalent chronic diseases and disorders killing adults today, especially heart disease, cancer and diabetes.
- Oxidation lays the foundation for the proliferation of free radicals and damage to cells, muscles, tissue, organs, etc.
Antioxidants counteract free radicals because they’re essentially “self-sacrificing soldiers.” As Byrnes explains, they donate an electron to free radicals to “calm” them down and are consumed in the process.
Our bodies use antioxidants to lessen the impact of free radicals, and our diets give us the tools to do so. Glutathione is considered the most important “master” antioxidant and is the liver’s major weapon. It’s created from the amino acids cysteine, glycine and glutamic acid.
Other major antioxidants that have been identified include some you’re likely familiar with, such as vitamins A, C and E; beta-carotene; bioflavonoids; CoQ10; selenium; and zinc. Copper and manganese have roles in antioxidant production as well.
Many other phytochemicals from plants also seem to play antioxidant roles. We usually think of these chemicals — like lycopene, tannins, phenols, lignans or quercetin, for example— as antioxidants even though the body doesn’t make them on its own. Once consumed they help reduce inflammation and the effects from oxidation. (4)
Here are some of the roles that antioxidants have:
- The antioxidant lipoic acid repairs essential enzymes in the body.
- Melatonin is an important antioxidant linked to regulation of the circadian rhythm (sleep/wake cycle).
- Even cholesterol can have antioxidant benefits. “Good” HDL cholesterol in some ways acts as a powerful antioxidant by repairing damaged blood vessels and reducing oxidation, meaning the addition of oxygen to low-density lipoproteins (LDL or “bad” cholesterol). This helps stop the buildup of fatty plaque on artery walls (atherosclerosis) and keeps blood flowing to the heart.
Our ability to produce antioxidants in the body declines with age, says Mayo Clinic’s Dr. Donald Hensrud. The reason that antioxidants are often touted as “anti-aging” compounds is because they help protect us from age-related diseases, which are caused in part by free radicals and inflammation. While we can never entirely stop the aging process, as diet high in antioxidant foods helps us age much more gracefully — living longer, healthier, more vibrant lives.
Major Sources of Free Radicals
So what causes free radicals to proliferate? Basically, the typical “Western lifestyle” — with its processed foods, absence of healthy whole foods, reliance on medications and antibiotics, common use of alcohol or drugs, environmental pollutants, and high stress levels. Free radicals are generated due to oxidation and when toxins are broken down in the body. The liver produces free radicals as it breaks down compounds and removes them.
The major sources of free radicals include: (5)
- Ordinary body functions, such as breathing and digestion
- Exposure to radiation
- Exposure to other environmental pollutants
- Consumption of cigarettes or tobacco, drugs, and alcohol
- Certain medications or high use of antibiotics, which leads to antibiotic resistance
- A poor diet that includes foods like unhealthy fats, too much sugar, pesticides, herbicides or synthetic additives. Many processed and refined foods contain oxidized fats that add free radicals to the body. Excessive amounts of sugar and sweeteners are other sources of free radical growth that contribute to aging, weight gain and inflammation.
- Even too much exercise (overtraining) generates added free radicals
- High amounts of emotional or physical stress. Stress hormones (like too much cortisol) can generate free radicals.