Antioxidants are quite popular nowadays. Superfoods are evaluated not only based on their nutritional value but also based on their antioxidant contents. Given a choice between similar foods or supplements of equal nutritional value, consumers often go for the ones with higher antioxidant content.
Most people who have heard of the term antioxidants know that it’s something healthy. But not everyone really knows how antioxidants work to protect our bodies. There are basically three ways that antioxidants work for our benefit. Read on to find out exactly how antioxidants help keep us healthy.
#1 Prevent Free Radical Formation
First-line defense antioxidants help prevent the formation of free radicals in the body. Defined simply, free radicals refer to any atom that contains one or more unpaired electron. Free radicals are dangerous because the unpaired electron that it contains will always want to pair or bond with another atom or molecule.
When free radicals pair up with a molecule that it’s not supposed to bond with, it could end up causing damage by modifying the structure of the other molecule and how it’s supposed to work in the body. For example, a free radical can bond with a nucleic acid. Nucleic acids are the ones that make up our DNA. So if one of the nucleic acids in the DNA is modified by a free radical, it can cause cellular abnormalities, and can even lead to the formation of cancer cells.
There are many ways free radicals can cause damage to our bodies. First off, the walls of our cells are largely made of lipids. Free radicals can attach to the lipids in our cell membrane and cause damage to the cells or impair the cell membrane’s functions. Free radicals can also attack the lysosomes in our cells. When these lysosomes are destroyed by free radicals, enzymes are released which cause the cell to self-destruct and digest itself.
There are three important enzymes in our body that are considered as the first-line antioxidant defense mechanism. These are superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT). The three enzymes are naturally produced by our body which is why they are considered as endogenous antioxidants.
Another reason why they are considered the most important antioxidant defense of our body is that these three enzymes can actually eliminate or neutralize millions of free radicals. The three important enzymes neutralize superoxide radicals, hydroperoxides, and hydrogen peroxides and convert them to molecules like oxygen that don’t cause harm to the body.
#2 Free Radical Scavenging
Even when we have a lot of primary or first-line defense antioxidants that can prevent the formation of free radicals, there will always be free radicals in our body. This is because even our normal body functioning can cause the formation of free radicals. For instance, when we breathe, there are enzymatic reactions involved that naturally cause the formation of free radicals.
Our body’s second line of antioxidant defense system actively searches for these existing free radicals and neutralize them. These antioxidants are known as scavenging antioxidants because of the way they actively seek out their target free radicals. Some of the more popular second-line defense antioxidants include uric acid, glutathione, ascorbic acid, vitamin E in the form of alpha-tocopherol, and ubiquinol.
Ascorbic acid or vitamin C and other secondary antioxidants seek out active free radicals. Once a free radical target is found, it is neutralized by the antioxidant through the transfer of an electron from the antioxidant to the radical. This process stops the neutralized free radicals from further forming chains and from causing damaging chain reactions.
However, when these antioxidants bind with the free radicals, the antioxidant becomes a free radical itself because of its unpaired electron. But this time, they are easy to neutralize and other antioxidants can make them completely harmless. The only unfortunate thing about the process is that these secondary antioxidants can only neutralize one free radical at a time.
#3 Radical-Induced Damage Repair
The third line of defense only gets involved when the free radicals have already caused damage. This is because the third line defense system is primarily geared towards repairing the damage. These third level antioxidants work on damaged lipids, DNA, and proteins, and repair whatever damage the free radicals might have caused.
Another function of tertiary antioxidants is to clean up after free radicals have caused damage. These antioxidants work by removing or breaking down oxidized or damaged lipids, proteins, and DNA materials. By doing so, the accumulation of these damaged compounds is prevented, thereby also preventing them from reaching toxic concentrations.
Third line defense antioxidants include proteolytic enzymes and the DNA repair enzyme. When there’s a cell membrane damaged by a free radical, these tertiary antioxidants work to reconstitute the cell membrane, keeping it whole and properly functioning again. The DNA repair enzyme, on the other hand, works on DNA materials that have been damaged by free radicals.
Popular Antioxidants And How They Work
Of the many antioxidants discovered so far, some of the most popular include vitamins A, C, E, and K, carotenoids like lycopene and lutein, and polyphenols like flavonoids. These antioxidants are also referred to as non-enzymatic antioxidants and they function in various ways to protect our body from free radical-induced damage.
For instance, vitamin E or alpha-tocopherol works as a chain breaker. This means that vitamin E stops chain reactions caused by free radicals. More specifically, because vitamin E is a lipid-soluble antioxidant, it works on lipids that have been or are being attacked by free radicals. Curcumin, found in ginger and turmeric, works like vitamin E does by stopping free radicals from causing chain reactions.
On the other hand, flavonoids like catechin, the antioxidant found in green tea, helps protect our DNA from hydroxyl radicals. Carotenoids such as lycopene and beta-carotene seek out peroxyl radicals and neutralize them to prevent damage to lipids found in cells. Like carotenoids, allicin in garlic also scavenges and neutralizes peroxyl radicals. Uric acid which is naturally found in our bodies is another powerful scavenger of free radicals. In aqueous environments, uric acid works on peroxyl radicals and carbon-centered radicals.