Database of diseases - Practical psychiatry and psychogeriatry

The free radicals theory is the most popular explanation of the causes of aging   . The first publications on free radicals are from 1956. This theory is based on the assumption that changes leading to aging are induced by damage to cellular macromolecules (DNA, proteins, lipids, carbohydrates) that arise from the action of free radicals. Free radicals are highly reactive atoms or molecules that have a free electron in the outer orbit. Their structure and ability to donate electron makes it particularly easy to react with many compounds. They often react with DNA and phospholipids of cell membranes, altering the antigenicity of cell membranes. In addition, they inhibit the synthesis of prostaglandins and thereby facilitate the development of atherosclerosis. It was noticed that in the brain of patients with Parkinson's disease or Alzheimer's disease they accumulate in neuromelanin, which is formed as a result of free radicals. .

Free radicals destroy the inside of the cells 

They cause damage to cellular lipids, which can be manifested by the accumulation of senile pigment in cells, as well as damage to proteins and DNA as well as mitochondria. These injuries lead to disorders in the functioning of their aging cells, and then to their death. The living organism has numerous mechanisms that neutralize radicals, but during the course of life, cell damage is accumulated. . Free radicals destroy the genes of longevity . Nematode Ceanorhabditis elegans has been a model organism for studying the processes of aging, apoptosis and cell cycle for years. It is known that in stressful situations, for example in the absence of food, he enters the stage of stopping development, in which the worm's metabolism is released to the minimum to survive in these difficult conditions. The stadium is called dauer, from the German word for persistence. Dauer not only allows you to survive stress, but also to extend the life of the nematode. Melendez and Levine have determined which gene is responsible for entering the dauer worm. This gene, called bec-1, is responsible for a process called autophagy, which involves the secondary processing of proteins that are no longer needed inside the cell. Unnecessary cellular proteins are digested and broken down into individual building blocks in the form of short chains or single amino acids, from which new proteins can then be produced. In this way, once formed amino acids and short peptides (short chains of linked amino acids) can be repeatedly used, which saves energy and raw materials. It was established that without active bec-1 nematode C. elegans can not enter the dauer stage, which prevents survival in stressful situations and shortens the life of the worm. The bec-1 genes involved in the processing of cellular proteins have also been identified in yeasts and mammals. Studies have shown that not only yeasts and worms, but also people owe their longevity to the sirtuin 3 gene, among others. The research was carried out on 801 people from the university's surroundings (of which 120 were centenarians). It turned out that older men (but not women) much more than young have two copies of one of the varieties of the sirtuin gene 3. This gene encodes the protein necessary in cellular mitochondria. This would confirm the theory that aging is associated with the accumulation of highly reactive free radicals produced in the mitochondria. Antioxidants can prolong life . It has been shown experimentally that it manages to prolong the life of laboratory animals by enriching the diet with antioxidant vitamins. Similar effects were obtained when animals used caloric restriction, thus extending the life time of animals by up to 50%. Due to environmental pollution and ionizing radiation, the human body is more and more exposed to free radicals. However, it is worth remembering that their source is also a diet abundant in saturated fatty acids. Free radicals damaging cell membranes and inducing chain reactions lead to the development of so-called free radical diseases. The lack of balance between active forms of oxygen and antioxidants is known by the concept of oxidative stress. Its occurrence favors the oxidation reactions involved in the pathogenesis of atherosclerosis. Here is a list of diseases in which free radicals are involved in the pathogenesis:     Atherosclerosis (including coronary, cerebral, renal, intestinal and peripheral circulatory abnormalities).
• Diabetes and diabetic angiopathy.
• Lung diseases (chronic spastic bronchitis, bronchial asthma, emphysema).
• Cataracts.
• Tumors (especially caused by environmental damages).
• Parkinson's disease.
• Various poisoning. . Scientific implications of the free radical theory
The theory of free radicals is consistent with the theory of aging of the body, and at the same time combines and complements all other theories. The use of antioxidative therapy therefore has a strong scientific justification. He often acknowledges the aging of the organism as an inevitable process waiting for all people, and for the reason - genetically conditioned. The genetically determined hereditary factor determines the length of life, both individual and species. Aging is an inevitable and irreversible change of living matter that occurs in it as a result of the passage of time. According to the authors of this theory, ages are not only living plasma, but also inanimate matter. Even the radioactive decay of elements can be considered as the aging of matter, and in this dimension it is a general cosmic phenomenon.

Aging is therefore a complex process that is difficult to explain with only one mechanism and many factors play an important role here and the presented theories provide a lot of information for research on this mysterious process.

     Doctor of Medicine Janusz Krzyżowski
Psychiatrist
Private office tel. 22 833 18 68
00-774Warszawa, Dolna 4 lok. 15    .