What are Free Radicals? (1, 2)
Free radicals are atoms present in an unstable form, which have a tendency for damaging the cells resulting in aging and illness. Free radicals are associated with a variety of health problems including aging; however, not much is known of their function in the health of human beings or how one can stop them from causing illness in people.
Free radicals are thought to cause changes related to age, such as causing grey hair and wrinkles. One needs to have a basic knowledge of chemistry to understand free radicals.
Electrons surround the atoms in layers known as shells. Every shell has to be filled by a particular number of electrons. After a shell is full; then electrons start to occupy the next shell.
Formation of Free Radicals (2)
If there is an atom present, which has incomplete outer shell, which is not full, then it can connect with another atom in order to complete its outer shell with the help of electrons. These kinds of atoms formed from incomplete shells and getting attached to other atoms to complete themselves are known as FREE RADICALS.
Atoms having a complete outer shell are stable; however, free radicals are unstable atoms and in trying to fill the electrons in outer shell, these free radicals will rapidly react with other substances.
What is Oxidative Stress? (1, 3)
When oxygen molecules get divided into single atoms having unpaired electrons, they turn into unstable free radicals, which search for other molecules or atoms to attach to. As this continues to occur, it results in a process known as OXIDATIVE STRESS. This oxidative stress causes damage to the cells of the body causing various diseases and aging symptoms, such as wrinkles.
How Do Free Radicals Affect The Body?
As mentioned before, free radicals are nothing but unstable atoms or atoms lacking the complete electron layer; and in order to become stable or get the needed electrons, they attach to electrons present in other atoms. This causes medical issues and signs of aging.
In 1956, the free radical theory of aging was first described and according to this, free radicals cause breakdown of cells over a period of time.(4)
As the body grows older, there is loss of its ability to combat the effects of free radicals, which leads to increased free radicals, increased cell damage, increased oxidative stress resulting in degenerative processes along with the normal aging process.
Even though the free radical theory of aging is comparatively new, there are many studies supporting it. Various studies done on rats have revealed a substantial increase in free radicals, as the aging process continued in the rats.(5) These changes resembled the health decline associated with age.
As time went on, researchers have modified this free radical theory of aging to concentrate on mitochondria, which are the small organelles responsible for processing the nutrients for the cells.(6) The research done on rats revealed that free radicals created in the mitochondria cause disruption in the substances needed by cell to function properly. This in turn leads to more production of free radicals, which again speeds up the damage to the cell.
This theory helps in understanding aging, as aging increases over time. The slow, but doubly fast accumulation of free radicals gives an explanation for aging and deterioration of even healthy bodies.
Different theories and studies have made the connection of oxidative stress caused by free radicals to:
- Cardiovascular disease caused by clogged arteries.
- Diseases of the central nervous system, such as dementias and Alzheimer’s.
- Age-related vision decline and cataracts.(7)
- Inflammatory and autoimmune disorders, such as cancer and rheumatoid arthritis.(8)
- Changes in appearance related to age, such as wrinkles, loss of skin elasticity, changes in hair texture, hair loss and graying hair.
- Diabetes.
- Genetic degenerative diseases, such as Parkinson’s or Huntington’s disease.
What Causes the Production of Free Radicals? (9)
Free radical theories of disease and aging can help us understand the reason why some individuals age slowly when compared to others. Free radicals are naturally produced in the body; however, certain lifestyle factors increase their production, such as: Eating fried foods, smoking, drinking alcohol and exposure to harmful chemicals, air pollution and pesticides.
All these lifestyle factors have been associated with cardiovascular disease and cancer amongst others. This is why one can come to a conclusion that oxidative stress is the reason why disease occurs after exposure to these substances.
What is the Connection Between Antioxidants and Free Radicals? (10)
Antioxidants are helpful in preventing the harmful effects caused by free radicals. Antioxidants are naturally found in food items, such as carrots, citrus fruits, berries and soy products.
These days the internet is flooded with many advertisements with products containing antioxidants to fight aging and what not. Antioxidants are the molecules, which help in preventing other molecules from oxidation.
Antioxidants help in preventing or reducing harmful effects of free radicals. Antioxidants provide electrons to the free radicals, hence decreasing their reactivity. This is a unique thing about antioxidants where they are able to give an electron without converting into free radicals that are reactive in nature themselves.
There is not a single antioxidant, which can prevent the effects of free radicals. Different free radicals have different type of effects on various parts of the body; and similarly each and every antioxidant acts differently according to its chemical properties.
In certain circumstances there are some antioxidants, which can turn into pro-oxidants that snatch electrons from other molecules producing instability in the chemicals resulting in oxidative stress.
Antioxidant Foods and Antioxidant Supplements: How Effective Are They? (15, 16, 17)
There are so many molecules and chemicals, which act as antioxidants, such as beta-carotene, glutathione, Vitamins C and E and phytoestrogens (plant estrogens). All these are some of the antioxidants, which are effective in counteracting the negative effects of free radicals.
Seeing that antioxidants are abundantly present in various foods has prompted health experts in recommending diets rich in antioxidants. Thanks to the antioxidant theory with regards to aging, there are many companies which are producing and advertising antioxidant supplements.
Some of the antioxidants-rich foods are citrus fruits, berries and other fruits, which are full of vitamin C. Carrots are loaded with beta-carotene and the soy present in soybeans and certain meat replacement are full of phytoestrogens.
Studies on antioxidants are varied and majority of the research has revealed very less or no benefits. A study done in 2010 on antioxidant supplementation for preventing prostate cancer yielded no results.(11) A study done in 2012 established that antioxidants were not beneficial in decreasing the risk of cancer of the lungs.(12)
On the contrary, individuals such as smokers who are at increased risk of cancer; are more on the slightly higher risk with antioxidants.
There is some research that revealed antioxidant supplements can be harmful; especially if taken more than the recommended or prescribed dose. Increased doses of vitamin E and beta-carotene are shown to increase the risk of death.(13)
Some studies have also shown benefits of antioxidant use; however, the results have been poor. A study in 2007 showed that continuous use of beta-carotene can slightly cut down the risk of problems associated with aging when it comes to thinking.(14)
What We Know and What We Do Not Know?
According to studies, antioxidants will not be able to “cure” the free radicals effects, especially when antioxidants are sourced artificially. This has given rise to questions regarding the authenticity of free radicals and why they develop.
Free radicals can be an early sign of inflammation where the cells in the body are fighting a disease. The formation of free radicals is also inevitable as one ages. More studies are needed to completely understand the issue of free radicals.
Individuals who want to counteract aging associated with free radicals should stay away from free radicals, such as fried food and pollution. To avoid the free radical effects one should focus on consuming a healthy and balanced diet rich in antioxidants instead of thinking about antioxidant supplements.
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3614697/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3249911/
- https://pubmed.ncbi.nlm.nih.gov/10693912/
- https://www.uccs.edu/Documents/rmelamed/harman_1956_13332224.pdf
- http://www.sciencedirect.com/science/article/pii/0047637487900571?via%3Dihub
- http://www.sciencedirect.com/science/article/pii/S0531556509000023
- https://www.ncbi.nlm.nih.gov/pubmed/7785961
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3614697/
- https://hopes.stanford.edu/about-free-radical-damage/
- https://www.hsph.harvard.edu/nutritionsource/antioxidants/
- http://www.tandfonline.com/doi/abs/10.1080/01635581.2010.494335
- http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD002141.pub2/abstract
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3765487/
- https://www.ncbi.nlm.nih.gov/pubmed/17998490?dopt=Citation
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3093095/
- https://www.nccih.nih.gov/health/antioxidants-in-depth
- https://www.frontiersin.org/articles/10.3389/fphar.2016.00024/full