Monday - Dec 09, 2019

How Free Radicals Combat Aging?


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We know that free radicals are harmful to our health.  Past researches have shown that free radicals are damaging molecules that contribute to aging process.  But an interesting study from Mc Gill University in Canada proved that free radicals can actually prolong the lifespan rather than shorten it.

What are Free Radicals?

Free radicals are unstable and reactive oxidants having one unpaired electrons. It can come from external sources like exposure to environmental pollutions or from smoking.  It can also be formed naturally inside the body. When free radical interacts with the body, it targets the DNA and or the protein components that cause chemical reactions which then damages its chemical structure.

Previous researches have shown that cells that are constantly exposed to free radicals will contribute to the aging process. But in a study entitled “The Intrinsic Apoptosis Pathway Mediates the Pro-longevity Response to Mitochnodrial ROS in C. elegans” which was recently published in the Cell journal, the scientist presented an opposite effect of free radicals with regards to aging.  The senior author Seigfried Hekemi of the research team, who is associated with the Department of Biology at McGill University, reported that they use the roundworm nematode with a scientific name – Caenorhabditis elegans as their model organism. 

The result was controversial considering that it opposed what people used to believe in about free radicals. The team found out that free radicals can actually stimulate apoptosis.  Programmed cell death or apoptosis is a normal process that takes place in the body. 

Damage cells undergo apoptosis or cell suicide to prevent them from being cancerous.  This is an auto-immune response of the body to destroy viruses that works by taking over to the cell’s normal processes. The researchers discovered that when free radicals triggers apoptosis, the cell’s natural defenses are reinforced, thus increasing their lifespan. 

Hekemi stressed that what people usually believe that these free radicals are unhealthy and can contribute to the aging process is actually incorrect. He also contradicts the Free Radical Theory of aging, and he pointed out that the opposite of this theory can be true. 

Free Radical Theory of Aging

According to the Free Radical Theory of Aging, free radicals causes damage to our cells through the oxidative stress that the oxygen-free radical causes.  This is the main reason why the human body undergoes the aging process.  They believe that when a person is younger, the cells have a defense mechanism which is known as superoxide dismutase or SOD that reins over the free radicals.

As one get older, the SOD is no longer active as it is before. The weakening of the SOD, allowed a chance for the free radicals to cause damage to the cells.  If the damage is too much, it can cause the death of the cells.

Free radicals have been linked to various conditions and diseases that are related to aging such as cancer, heart disease and dementia. But not everyone agrees with the theory because people argue about which comes first – the unhealthy free radicals or the aging process?  Others argue also that it could be possible that when free radicals have induced damage to the cells, that’s the time when aging begins. They also argue whether if free radicals can be tamed, can it postponed the aging process?

What Does the Findings Say?

According to Hekemi and his team, their findings have proved that the production of free radicals increases during the aging process because these unhealthy molecules actually combat aging not causes it.  They also pointed out that through their model organism, they were able to show that when they elevated the generation of free radicals it then increases the longevity of the cell’s life.

The researchers added that the molecular mechanism of free radical production induces the increase lifespan of the cell.  This showed that indeed free radicals have a positive effect on the signaling molecules of the cells. Contrary, to what earlier researches have pointed out, free radicals does not induce the aging process but in reality they actually prevent it.

Apoptosis signaling occurs because it is used to stimulate the processes that slow down aging. Hekemi added that process of apoptosis has been comprehensively studied because of its significant role in cancer and immunity.  Pharmacological tools that are widely used are designed to manipulate the apoptotic signaling.

Hekemi noted that understanding the process of apoptosis signaling is important in treating neurodegenerative disorders.  He pointed out that the apoptotic signaling in the brain is focused on increasing the resistance capability of the damaged cells rather than destroying it considering that it is difficult to restore dead neurons compared with other cells because of the complexities of interconnections of the neurons.

What is the Implication of the Study?

The researchers have taken their study one step further by showing the possibility of how free radicals can actually promote longevity through their model organism, C. elegans. The findings of the study was surprising considering that free radicals or oxidants was involved on a molecular mechanism that signals the cells to kill themselves to prevent further damage to the other healthier cells.  The researchers pointed out that if the same molecular mechanism is stimulated in a right way, this would reinforce the defense mechanism of the cell, thus increasing its lifespan.