Many people have heard that antioxidants protect us from free radical damage in our bodies. But what exactly are free radicals, why are they bad and where do they come from?
Free Radical Damage
Free radicals can be very harmful components, but they’re also essential players in our immune system. Our bodies produce free radicals as byproducts of cellular reactions; the liver produces and uses free radicals to detoxify; white blood cells send free radicals to destroy bacteria, viruses and damaged cells.
So why are they thought to be dangerous? As naturopath Dr. Stephen Byrnes explains, free radicals are unstable molecules. Electrons exist in pairs and free radicals are missing an electron. This is their weapon of sorts. They “react” with just about anything they come into contact with, robbing cells and compounds of one of their electrons.
This makes the affected cell or compound unable to function and turns some cells into electron-seeking muggers themselves, leading to a chain reaction in the body and the proliferation of free radicals. Free radicals damage DNA, cellular membranes and enzymes.
Normally, free radicals, or as they’re also referred to, reactive oxygen species (ROS) and reactive nitrogen species (RNS), live in balance with antioxidants in the body. It is when this balance is disturbed and free radicals multiply that damage is done. The clean-up crew, our immune system’s soldiers, loses their control and end up marauding and pillaging throughout the body, affecting healthy cells.
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. When antioxidant levels in the body are lower than that of free radicals due to poor nutrition, or they are being used to battle other incoming toxins, oxidation wreaks havoc in the body, damaging cells, breaking down tissue, mutating DNA and overloading the immune system. The amount of oxidation in the body is a measure of oxidative stress.
Oxidative stress (OS) is believed to lead to the development of disease and disorders.
High levels of oxidative stress affect every organ and system in the body and have been linked with everything from Alzheimer’s disease, arthrosclerosis, cancer and heart disease to accelerated aging, asthma, diabetes and leaky gut syndrome.
Free Radical Sources
So what causes free radicals to proliferate? Environmental pollutants, alcohol, smoking, unhealthy fats and even too much exercise generates added free radicals.
Free radicals are generated when toxins are broken down in the body. 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.
Stress hormones generate free radicals. The liver produces free radicals as it breaks down compounds and detoxifies the body.
The Western lifestyle, with its processed foods, absence of healthy whole foods, reliance on medications and drugs, environmental pollutants and high stress levels all lay the foundation for the proliferation of free radicals and damage due to oxidative stress.
Antioxidants and What They Do
Antioxidants are self-sacrificing soldiers. As Dr. Byrnes explains, they donate an electron to free radicals to “calm” them down and are consumed in the process.
Our bodies produce antioxidants as a matter of course and our diets give us the tools to do so. Glutathione is the most important antioxidant and is the liver’s major big-hitter. It is created from the amino acids cysteine, glycine and glutamic acid.
Other major antioxidants that have been so far identified are: vitamins A, C and E, betacarotene, bioflavonoids, CoQ10, selenium and zinc.Copper and manganese have roles in antioxidant production.
Many other phytochemicals from plants also seem to play antioxidant roles.
The antioxidant lipoic acid repairs essential enzymes in the body; melatonin is an important antioxidant; even cholesterol acts as a powerful antioxidant, repairing damaged blood vessels.
Our ability to produce antioxidants in the body declines with age, says Mayo Clinic’s Donald Hensrud,but although antioxidants are often touted as “anti-aging” compounds; the evidence so far, says microbiologist TI Mbata, is that plant foods protect us from age-related diseases rather than halt or reverse the aging process itself. This allows us to age much more gracefully, living longer, healthier, more vibrant lives.
30% of Americans are taking some form of antioxidant supplement. But the American Heart Association, along with the Mayo Clinic and Cleveland Clinic, recommend getting antioxidants from whole foods and a wide variety of foods instead.
Dr. Hensrud points out that most foods with high ORAC scores offer other great benefits in terms of fiber, proteins, vitamins and minerals. The Cleveland Clinic points out that plant food in whole form contain flavonoids and lycopenes that play antioxidant roles.
Based on a 2005 review, TI Mbata worries that people rely on supplements to counteract unhealthy lifestyles and poor nutrition, and worries that too many antioxidants may compromise the defensive role of free radicals in the immune system.
Isolating specific antioxidants and consuming them isn’t very helpful, Mbata says. It is the variety and interaction of many different antioxidants as they exist in foods that seem to be beneficial.
There are “literally thousands of different antioxidants in the human diet,” Mbata writes, and they exist in many different forms. Some scientists believe that only in food form do antioxidants interact beneficially with our bodies.
Author of In Defense of Food, Michael Pollan, calls this obsession with finding the magical and pivotal ingredient in foods “nutritionism” and “reductionist science” and believes that it actually promotes unhealthy eating.
Looking at foods from the perspective of the specific nutrients they contain dissolves “distinctions between processed foods and whole foods,” Pollan says. It’s easier to post “contains essential vitamins and minerals” or “contains antioxidants vitamins C and E” on a box of processed cereal than it is to label a banana or a carrot in the same way.
“People don’t eat nutrients,” Pollan says. “They eat foods, and foods can behave very differently than the nutrients they contain.”
Foods Rich in Antioxidants
The real bottom line is that while it’s helpful to be aware of antioxidants and their benefit; the real benefit comes from eating a wide variety of whole foods and reducing toxin load in your body by:
- avoiding environmental pollutants in water
- reducing chemical exposure in household and cosmetic products
- limiting intake of processed and refined foods
- limiting intake of pesticide and herbicide-laden foods
- limiting intake of antibiotic and hormone-laden foods
- avoiding over-use of medications
- reducing stress
- getting moderate amounts of exercise
- using natural, cold-pressed oils (heat oxidizes fats in refined oils)
The National Institute on Aging in the National Institutes of Health has developed a scoring system to measure the amounts of antioxidants in foods known as an ORAC score. ORAC stands for Oxygen Radical Absorbance Capacity. Here are just a few foods that have high ORAC scores:
Brightly colored fruits and vegetables
Orange foods like carrots, sweet potatoes, pumpkin & cantaloupe contain cartenoids which can reduce sunburn and wrinkles. Citrus fruits contain quercitin. Spinach & kale are high in lutein, and tomatoes & red peppers contain lycopene.
Berries are the fruits highest in antioxidants. A study in the Journal of Agricultural & Food Chemistry found berries an easy winner in the amount of antioxidants for the price. As an added bonus, berries also tend to be lower in sugar than other fruits.
Green and white tea
White and green teas are very minimally processed and contain less caffeine than coffee or even other varieties of tea. They also contain a very high concentration of antioxidants called polyphenols that have been shown to have cancer fighting properties.
A study from the Seoul National University has shown that cocoa has a higher antioxidant content that green tea, black tea and even red wine! But you want to make sure the cocoa you are eating is very minimally processed.
Weston A. Price Foundation (2003)
Internet Journal of Food Safety (2005)
The Cochrane Library (2010)