You hear a lot about antioxidants these days. Many people like to taut their benefits. But what are they? How do they work? Where do they come from? Should you be including them in your diet?
What is an antioxidant?
Here's the dictionary definition:
That's pretty clear, right? You take antioxidants, and you won't be damaged by oxidizing agents, whatever that means. Let's dive a little deeper.
According to eatwell.org, "our bodies are battlegrounds against infection and diseases. Normal body functions such as breathing or physical activity and other lifestyle habits such as smoking produce substances called free radicals that attack healthy cells. When these healthy cells are weakened, they are more susceptible to cardiovascular disease and certain types of cancers. Antioxidants, such as vitamins C and E and carotenoids, which include beta-carotene, lycopene and lutein, help protect healthy cells from damage caused by free radicals."
So it seems like if we want to know more about antioxidants, we need to know more about free radicals. And we're not talking James Dean here.
What is a free radical?
According to rice.edu, free radicals are atoms or groups of atoms with an odd (unpaired) number of electrons and can be formed when oxygen interacts with certain molecules. Once formed these highly reactive radicals can start a chain reaction, like dominoes. Their chief danger comes from the damage they can do when they react with important cellular components such as DNA, or the cell membrane. Cells may function poorly or die if this occurs.
Some free radicals arise normally during metabolism. Sometimes the body's immune system?s cells purposefully create them to neutralize viruses and bacteria. However, environmental factors such as pollution, radiation, cigarette smoke and herbicides can also spawn free radicals. Check out the graphic below for some sources of free radicals.
One other surprising source of free radicals is exercise. Exercise, because it requires increased oxygen consumption, also increases the production of free radicals.
So what you need to know is that free radicals come from internal and external sources and that they are unstable. Generally, free radicals attack the nearest stable molecule, "stealing" its electron. When the "attacked" molecule loses its electron, it becomes a free radical itself, beginning a chain reaction. Once the process is started, it can cascade, finally resulting in the disruption of a living cell.
How do these disruptions surface in our bodies? Free radicals disturb the action of cellular DNA, which directs key cellular activities. Cells with damaged DNA stagnate and are prone to developing cancer and growths. This kind of damage also accelerates the aging process, directly causing wrinkles and age spots and severely taxing the immune system. Other diseases such as heart disease, atherosclerosis, Parkinson's disease, Alzheimer's, inflammatory joint disease and degenerative eye disease to name a few are also attributed to free radicals (source: purenewyou.com).
Antioxidants to the rescue
Sounds pretty bad, all of these free radicals roaming our bodies causing cell damage and disease. How can they be stopped? That's where antioxidants come in. Antioxidants neutralize free radicals by donating one of their own electrons, ending the electron-"stealing" reaction. The antioxidant nutrients themselves don't become free radicals by donating an electron because they are stable in either form They act as scavengers, helping to prevent cell and tissue damage that could lead to cellular damage and disease (source: healthchecksystems.com).
Doesn't that sound wonderful? These altruistic antioxidants donate their electrons to disable the menacing free radicals. How do I get my hands (or body) on these wonder nutrients?
Sources of antioxidants
The table below shows 20 common foods that are great sources of antioxidants (source: WebMD).
You'll notice that we're talking about beans, fruits and vegetables in this list. Another plug for healthy eating!
What about antioxidant supplements? Do I really need to eat all of this healthy food? In a word, yes. Most sources I looked at gave the same story - all of the supplements and foods that have been enriched with antioxidants can interfere with the normal metabolism of nutrients within the body, primarily because they contain a high concentration of antioxidants. So stick to natural sources for best results.
Too good to be true?
If you've read this far, great! Now you'll hear the deeper, darker side of the story, why free radical's aren't so bad and how antioxidants aren't always so great.
I mentioned earlier that exercise produces more free radicals. For this reason, it was suggested that athletes take antioxidant supplements in the form of Vitamins C and E. But studies over the past 10 years on rats have shown that free radicals, when produced through exercise, actually had jump-started a process that over time would allow the rats’ muscles to adapt to exercise. Suppressing the production of free radicals had, they concluded, prevented the ‘‘activation of important signaling pathways’’ and altered the muscles’ ability to adapt to exercise. As a result, they wrote, ‘‘the practice of taking antioxidants’’ to ward off the presumed free-radical damage caused by exercise ‘‘may have to be re-evaluated.’’ (source: nytimes.com) These results were also verified in human tests, to the point where although supplements didn't physically harm athletes, their own antioxidant defense systems weren't as strong and their insulin response was weaker.
Can free radicals be beneficial to our health?
Scientists agree that overall their role is destructive, and contribute to skin wrinkling, cancer progression and neurodegenerative diseases (source: Discovery.com). But in an interesting study published in PLoS Biology, worms that were treated with a free-radical-producing herbicide actually lived longer than normal worms. What's more, when the longer-lived mutant worms were given antioxidants, the effects were reversed, and the worms had a conventional worm lifespan. The finding flies in the face of the idea that antioxidants battle the effects of aging. According to study author Siegfried Hekimi of McGill University in Montreal and others, what is emerging from this and other experiments is a view of free radicals -- or, more precisely, reactive oxygen species -- as a normal part of the body's stress response, with beneficial effects at certain (low) levels. Hekimi and others point out that part of exercise's benefit may be because exercise causes mild increases in the levels of reactive oxygen species that are actually good for us.
Can antioxidants be bad for our health?
While antioxidants confer many benefits, taking too much of one or a few antioxidants at once or taking high doses over a long period can lead to problems. A meta-analysis of studies done by Cleveland Clinic found that beta-carotene supplements raised the risk of mortality significantly and slightly raised the risk of cardiovascular disease (source: livestrong.com). Another well-studied antioxidant that may cause harm when consumed in excess is vitamin E. According to the Office of Dietary Supplements, doses above 150 IU per day began to raise the risk of death, with the risk rising along with the dose. Doses of 50 to 400 IU per day have been linked to an increased risk of hemorrhagic stroke.
Also on a side note, when my son was going through chemotherapy for a cancerous tumor, we were told not to give him any antioxidant-containing food. Why? Because the point of chemotherapy is to destroy cells, much like free radicals do. So antioxidants would combat the effects of chemotherapy.
What about reducing sources of free radicals?
With all of the emphasis on how great antioxidants are in combating the evil free radicals, it seems like we are missing one key point. There are many sources of free radicals, like UV rays from the Sun, air pollution, radiation, smoking and inflammation caused by eating poorly. Although it's great to increase your intake of fruits and vegetables containing antioxidants, it is just as important to try and reduce sources of free radicals (rather than combat them with antioxidants). It is silly to smoke a cigarette and then eat some blueberries to combat its effects. So wear sunscreen, try not to breath pollution, and avoid poor food choices that cause inflammation (like sugar and refined carbohydrates). And yes, exercise.
The body is an amazing machine. It has brilliant defense mechanisms against disease that can help you as long as you treat it correctly.
Once again, my friends, it comes down to eating right and exercising. No pill or enhanced food can make you healthy if you're not willing to treat your body right.