Is it time to test medicines for old age on a person?
Scientists disagree on aging
Nadezhda Markina, "Newspaper.Ru"According to experts, by 2050, the number of people on Earth who have lived to 80 years will triple.
The part of humanity that will need care and suffer from infirmity and diseases will become three times larger. Will we be ready for this? Scientists from all over the world in their laboratories are actively researching various aspects of aging, analyzing them at the molecular level. But practical medicine is not yet ready to accept the challenge and slow down human aging by some means. Two different views on this problem are presented in the July issue of the journal Nature (Medical research: Treat aging).
One group of scientists – Luigi Fontana, professor of medicine at Washington University in St. Louis, Brian Kennedy, director of the Buck Institute for the Study of Aging, and Walter Longo, director of the Longevity Institute at the University of Southern California - believes that we already know enough about aging to move from animals to humans. Therefore, we can develop a program and begin clinical trials on humans of those drugs that slow down aging and prolong life in animals.
"The problems of aging come to us in a package," the authors of the article write. – More than 79% of people over the age of 65 have two or more chronic diseases, such as arthritis, diabetes, cancer, cardiovascular diseases, stroke, etc. Moreover, studies show that when we delay the onset of one disease with the help of diet or medications, others are also in no hurry to attack."
This group of scientists shares the point of view that it is more effective to deal not with individual diseases, but with old age as such. Then the diseases will go away. As Ilya Mechnikov said 100 years ago, "old age is a disease that needs to be treated." Consider aging a disease – this appeal to the World Health Organization was made by the participants of the international conference on the genetics of aging and longevity, held this year in Sochi.
In favor of this view, the authors of the article in Nature cite the results of experiments with mice. These rodents manage to prolong life by 50% by limiting calories in the diet and certain genetic influences. After these Methuselah mice do die, their internal organs show that heart and vascular problems, brain neurodegeneration and metabolic disorders affected them to a much lesser extent than normal mice.
"In other words, the prolongation of life turns out to be the prolongation of a healthy life, without chronic diseases," the scientists note. And this is exactly what a person would like.
But these studies are hardly recognized in medicine. Medicine deals with the treatment of individual diseases, such as Alzheimer's disease or heart failure, and not old age in general.
Although some means of healthy human longevity work in practice – it is a balanced and calorie-restricted diet and regular physical activity. It would seem that you can't think of anything better and you don't need any medications. But firstly, only very motivated and strong-willed people can force themselves to lead a healthy lifestyle. And secondly, scientists believe that the effectiveness of diet and sports can be enhanced by other methods.
According to the authors of the article, we are already ready to test anti-aging substances on humans based on the results obtained on animals.
Scientists already know quite a lot about aging, and they are digging into its molecular foundations. "Today we know at least a dozen molecular pathways involved in the process of physiological aging," Luigi Fontana and his colleagues write. It means that there are known cascades of biochemical reactions that lead to aging of cells, tissues and organs. Moreover, these molecular pathways are universal in mice and humans. By learning how to change them, choosing target molecules for exposure, you can control the aging process. The idea is this. And you can change it in different ways – genetic, hormonal, metabolic. The notorious calorie restriction, which really prolongs the life of laboratory animals, can be attributed to metabolic effects, since the metabolic rate decreases at the same time.
Apparently, this method also works on humans. At least, long-term calorie restriction in humans changes metabolism and molecular pathways quite a lot towards rejuvenation.
Scientists are inspired by the fact that aging and longevity are affected by some medications that have already been approved and used in the clinic, however, for completely different purposes. For example, a drug used in oncology and organ transplantation increases the life time of mice and nematode worms. Its mechanism is known: it affects the TOR signaling pathway that regulates various processes, from protein synthesis to cell reproduction and survival. Another example: diabetes medication also slows down aging in mice. Finally, the substance found in red wine acts on sirtuin proteins involved in various cellular processes and prolonging life in mice.
Interestingly, the effect of many of these substances mimics the effect of a restrictive diet. The same changes occur in the body as in the body of animals kept on a calorie- and protein-restricted diet, as well as the cellular response to stress increases and oxidative damage in cells decreases. According to the authors of the article, these substances can already be tested on humans as geroprotectors – anti-aging drugs.
For such tests, a very important link is needed – biomarkers, changes in physiological indicators that are easy to measure and by which you can judge the aging of the body or that it has slowed down. From animal studies, scientists already know many biomarkers of aging, it is necessary to determine which of them are most suitable for humans.
Scientists complain that aging research is underfunded. Much less money is allocated for this than for the fight against individual diseases. But most importantly, as they believe, the mentality should change. Society should want to invest money in attempts to slow down aging and prolong life. Otherwise, we will face a demographic crisis: an increase in infirmity and senile diseases and a rapid increase in health care costs, which we will not be able to overcome.
In an interview with a correspondent of "Gazeta.En" at a conference in Sochi, one of the authors of the article, Brian Kennedy, showed himself to be an optimist. In his opinion, now all studies converge at one point and it's time to move on to practice, it's time to treat aging. And in 20 years we will have 20 drugs that slow down aging.
The authors are opposed by another group of scientists – Douglas Sels, professor of the Department of Integrative Biology at the University of Colorado, and Simon Melov, director of Genomics at the Buck Institute for Aging Research.
They believe that before testing anti-aging products on a person, it is necessary to study how they affect the work of all organ systems. And to do this, it is not enough to know the key molecular pathways of aging, because manipulation of certain genes does not always lead to changes in the work of organs.
It is necessary to monitor how the work of the cardiovascular system, lungs, kidneys, brain, etc. decreases with aging. The means that we are testing against aging should slow down the decline in the work of all body systems. And there are not always adequate methods for testing the work of organs. And first you need to conduct such testing on animals, and then adapt these tests for humans.
Something is being done in this direction. For example, at the Mayo Clinic Life Extension Laboratory in Rochester, researchers measure age-related changes in muscle strength, cognitive impairment, body composition, metabolic rate, insulin sensitivity, motor coordination, bone density and physical capabilities.
At the same time, clinical trials of drugs to prevent age-related muscle atrophy and sarcopenia are underway. The National Institute of Health has developed a battery of age-related tests for humans, including tests for balance, memory, hand strength and perception.
As a result, the authors of the article urge researchers working with animals and working in the clinic to communicate more with each other in order to build a bridge from the study of aging to the treatment of aging.
Portal "Eternal youth" http://vechnayamolodost.ru18.08.2014