Why do we grow old? Prof. Tavernarakis talks about the mysteries of ageing
The question of why we age, grow old and die is one that has haunted humanity since the dawn of time, a recurrent theme in art, literature and poetry through the ages. Recently, science has started to unlock the answers to some these burning questions, revealing the mechanisms that underlie our path from youth to old age.
The Athens-Macedonian News Agency (ANA) talked about some of the latest breakthroughs in the science of ageing with Professor Nektarios Tavernarakis, at the School of Medicine of the University of Crete, and how they have furthered our understanding of the phenomenon, as well as ways to slow the progress of ageing and protect against the diseases that accompany old age.
“We already know some of the mechanisms in our cells that are responsible for ageing. One such mechanism, for example, is linked to the production of energy in our cells and certain organelles found in our cells called mitochondria…what we found in the laboratory, for the first time, is that damage to our mitochondria results in a reduction in the production of energy, on the one hand, and an increase in the production of the by-products of metabolism, such as oxygen free radicals, on the other hand,” Tavernarakis said.
As he explained, oxygen free radicals are molecules that cause the oxidation and destruction of cells, while disruption of the process of converting glucose to energy in cells is a key cause of cell damage and death.
“Essentially, when we have damage to mitochondria, this causes ageing. Cells are not defenceless, however. They have mechanisms for repairing the damage and one such mechanism is mitophagy. In other words, a mechanism that destroys the damaged mitochondria so they cannot cause harm. Younger cells can do this but, as time passes, the cells progressively lose their ability to renew their mitochondria, to destroy the damage ones and make fresh new ones that function.”
Ageing is associated with a number of degenerative diseases, including neurodegenerative diseases, cancer or type II diabetes, Tavernarakis said, whose incidence is much higher among older individuals. A great body of research is devoted to finding what triggers the onset of these diseases, many of which are linked to genes carried since childhood.
“We believe that by understanding the mechanisms of ageing, we can then use this knowledge to offer a better quality of life to older age groups. For this reason, there is a great need to understand ageing and what links it with these diseases, so we can use this knowledge to develop therapy strategies that can address this connection and break the link between the diseased state and advanced years, so we have a better quality of life in old age,” he said.
Can ageing be prevented or delayed, ANA asked. On this score, Prof. Tavernarakis said, the science of genetics was delivering some encouraging news.
“We have found that we can have very good results in cell survival, either using genetic methods, in other words intervening genetically to change some genes that are responsible for regulating the process of mitophagy, or by using chemical substances that result in the increase and activation of mitophagy. In fact, we can extend the life spans of laboratory animals. Already, experiments have been carried out on several laboratory animals that are being used in practice. This cannot be done on people, of course, but the knowledge can translate into practices that can be used on people,” he said.
Clinical trials were underway in the United States, Germany and Austria that used such chemical substances to activate mitophagy and allow cells to detoxify, Tavernarakis reported. One such drug was spermidin, found in certain plant products and fruit. Another such substance was metformin, which had been shown to have good results for ageing in lab animals and was now being tested on patients in the U.S. in clinical trials.
He also cited several other substances found in some natural products that had a beneficial effect on the ageing process, such as resveratrol in red wine or urolithin found in pomegranate juice and other plant sources.
“In people, the aim is not to extend life; the interest is focused on how exactly to attain a good quality of life in old age,” he said.
Asked for tips on how to achieve a healthy old age, Professor Tavernarakis said the main thing was to avoid exposure to factors that accelerate ageing, such as pollution and toxins, and ensure a health diet.
“One should avoid smoking and excessive exposure to ultraviolet radiation, to the sun. About 95 pct of skin ageing is due to exposure to UV radiation,” he pointed out. Another major factor was obesity, he noted, which had been shown to decrease life span and increase the chances of age-related diseases, such as cancer, diabetes, heart and circulation problems or metabolic ailments.
“We can also try to control another major factor, the environment. But our genetic blueprint we cannot change,” he added.