Antioxidants: What they are, What they do & What foods to eat
In the past few decades, the term “antioxidant” has become a popular term among health conscious shoppers. Antioxidants, present in a variety of foods, are understood to be key players in counteracting everything from cancer to arthritis to even the effects of aging. With so much buzz about the health benefits of antioxidants, many are left wondering what they are and how they work. And what foods should be eaten to maximize health benefits?
Why are Antioxidants Important?
Oxidation, sometimes called “biological rust,” is a natural process that occurs with all cells in nature including the ones in our bodies. It is a normal chemical process that plays an important role in our cells’ metabolism—the turning of food into energy. More precisely defined, oxidation is the loss of at least one electron when two or more substances interact.
“Oxidation is a process that’s necessary for us. If you slice an apple or banana and leave it out in the air it can turn brown. Our cells can do the same thing,” says Sharon Hopper, a nutritionist at Memorial Health System’s Center for Cancer Support.
One of the results of this oxidation is the production of free radicals—atoms or molecules that have a charge due to an excess or deficiency of electrons. Free radicals can also be present in food or air, while others are created as a result of exposure to tobacco smoke, radiation, toxins, sunlight, X-rays or excessive exercise.
Free radicals are highly unstable, and scavenge the body to donate or grab electrons. While they are helpful in performing some immune functions, in excess or in the wrong place, they can start a chain of damaging chemical reactions that result in damage to cellular and genetic material.
“When an atom—circled by a pair of electrons—is exposed to toxins, one of the electrons in an existing pair can be removed, causing free radical formation,” says Leslie Roberts, a nutritionist at Hamilton Diabetes and Nutrition Center. “In turn, the highly unstable atom [free radical] will seek out an additional electron from a neighboring molecule in order to regain stability. You can think of the free radical as a bully attacking an innocent atom in order to satisfy its need for stabilization. This process will lead to a chain reaction of free radical formation and ultimately the death of the cell.”
Cellular damage caused by free radicals has been linked to disease processes from cancer to heart disease to arthritis. It is also thought to contribute to the bodily deterioration that accompanies aging.
What are Antioxidants?
Antioxidants are compounds capable of counteracting the damaging effects of oxidation caused by free radicals. They donate their own electrons to stabilize the unstable free radicals, and do so without becoming electron-scavenging themselves.
While the body naturally creates many different types of antioxidant molecules to fight free radicals and protect cells from damage, its effectiveness in doing this can decline with age. However, antioxidants can also be gained through the foods we eat.
“Antioxidants are nutrients in food that help prevent oxidative damage and cell damage in our bodies that can lead to disease processes like heart disease and cancer,” says Hopper. “There are many forms of them in vitamins, minerals and phytochemicals that are naturally occurring compounds in plant foods. Some very common ones are vitamin C, vitamin E and vitamin A.”
“Antioxidants can prevent excessive oxidation in our bodies by slowing down the process or even repairing damages,” says Roberts. “Research has shown that people who eat a diet rich in antioxidants tend to have a decreased risk of developing many of the diseases linked to an excess of free radical formation.”
“Once an antioxidant donates and satisfies a free radical, it can no longer fulfill that function again,” she adds. “This is why we should continue to eat foods rich in antioxidants. It’s not just a one-time deal. We should have a continuous supply of them every day so we can continue to fight free radicals.”
What Foods are Rich in Antioxidants?
“If you look at the New American Plate or the New American Dietary Guidelines, you’ll see that they’re recommending that two-thirds to three-fourths of the plate be plant foods, and only one-fourth to onethird be protein,” says Hopper. “Vegetables, fruits and whole grains should make up two-thirds of the plate, and many of those will have antioxidants.”
Roberts agrees. “It’s important to get variety. Fruits and vegetables that are deep in color are particularly good. Yellow, orange, and red foods—like citrus fruits—are very high in vitamin C. Leafy greens like spinach, kale, collard greens, broccoli and brussel sprouts are very high in vitamin C and A. Deep red foods like watermelon or tomato or pink grapefruit are high in vitamin A and lycopene.”
Research Supports Health Benefits
Beginning in the 1990s, scientific researchers studying the function of specific compounds in foods made significant strides in understanding free radicals and antioxidants. Around that time, links were established between the destruction caused by free radicals and a whole host of negative conditions including cancer, atherosclerosis and vision loss.
Over the years as research progressed, that list grew to include arthritis, heart disease, Parkinson’s disease, Alzheimer’s disease and more. Simultaneously, research showed that diets containing ample intake of antioxidant-packed fruits and vegetables led to a notably decreased risk of these conditions.
This may seem straightforward and intuitive: that consuming more fruits and vegetables is good for you. However, the point is that antioxidants have been identified as one of the major, specific compounds within those fruits and vegetables that actively work to maintain or improve good health.
What scientists have not determined is the exact manner in which various types of antioxidants work together with other vitamins and nutrients to fight off free radicals and forge health benefits. However, it’s evident that maximum health benefits are derived from consuming a wide variety of antioxidants in vitamins and minerals found in a variety of food sources.
A Balanced Intake
Like Hopper and Roberts, most nutritionists agree that people should pursue a balanced diet of antioxidant-rich fruits, vegetables and grains. Antioxidants and vitamins are believed to work best in cohesion with one another rather than in isolation.
“Scientists are finding that if you get antioxidants in a wide variety of foods, it tends to help our bodies better than just getting a nutrient or two from one thing,” Hopper says. “They seem to do better when consumed with other nutrients.”
“It’s also wise for people to have a good general knowledge of the foods that contain antioxidants, including their caloric content,” says Roberts. “I would be cautious of saying to anyone, ‘If a food is high in antioxidants, then eat as much as you want.’ We want people to use good calorie knowledge too. Foods such as nuts, seeds and salmon are excellent sources of antioxidants, but they also contain a high fat and calorie content, so people should be mindful of their portions.”
That said, in the true pursuit of good health, the war against free radicals must be waged both by increasing antioxidant intake and by working towards decreasing the excess production of the free radicals themselves. “In combination with the diet, general lifestyle issues are importance. If you smoke, then you need to quit. Smoking is an external source that leads to free radical development. Daily physical activity and exercise will also help to fight off free radicals by reducing stress, enhancing overall health and strengthening the body’s immune system,” Roberts says.
Antioxidants play a vital role in achieving and maintaining good health. A diet rich in fruits, vegetables, nuts, berries and grains is a healthy and tasty way to increase antioxidant intake and strive for good health. The benefits are proven, and for the creatively minded, the potential for delicious, antioxidant-filled recipes is endless.