Андрей Фоменко – The Power Of Youth. How To Tune Our Mind And Body For A Long And Healthy Life (страница 6)

FUN FACT

ONLY 5-10 % OF DISEASE DEVELOPMENT DEPENDS ON GENETICS

Canadian scientists at the University of Alberta conducted the largest meta-analysis, summarizing data from 569 genetic studies over two decades, and concluded that the association between most human diseases and genetics is very low – only 5-10 %. This means that human life and health are not predetermined by genes, but depend more on lifestyle and environment.

In their work, the researchers studied the relationship between gene mutations known as single-nucleotide polymorphism (SNPs) and various diseases and conditions. Many SNPs are considered risk factors for the development of hundreds of diseases, but the results of a meta-analysis have shown that this relationship is highly questionable.

Experts have found that most diseases, including many cancers, diabetes mellitus type II, and Alzheimer's disease, are only 5-10 % or less dependent on genetic factors. However, there are exceptions: for example, Crohn's disease, gluten-sensitive enteropathy, and age-related macular degeneration, for which the genetic risk is 40–50 %.

Despite these rare exceptions, it has become apparent that in most cases the development of disease is related to metabolic disorders, environmental and lifestyle factors, or exposure to dangerous bacteria, viruses, and toxic substances. It can be concluded that we should not blame deviations in health on heredity, and it is better to monitor the ecological security in which people live and work: food, water, air quality, etc., as well as lead a healthy lifestyle.

We can monitor epigenetics in action through the observation of the lives of identical twins who have identical DNA at birth. These observations show how strong the differences in gene expression of twins can be if they live in different conditions and lead different lifestyles. In theory, the disease in twins should develop equally, but it is far from being true: depending on various factors, only one of them may have symptoms.

This finding supports a study conducted in 2005[28]. Scientists studied several dozen pairs of identical twins 3–74 years old. It turned out that people did have similar gene expression in childhood because they were in about the same conditions: they lived in the same house, went to the same school, and ate similar food. However, the older the twins got, the more differences there were between them. And when the siblings separated as adults, and started to lead different lifestyles, to have some different hobbies, to work in different fields, the number of these differences increased several times.

It is the same with ordinary people: as soon as you change your lifestyle in one way or another, your genes will manifest themselves differently. And this changed methylation profile we pass on to our children! Why don't we then take advantage of this ability to make genes work for better health, slower aging, and longer life? Knowing how the epigenetic mechanism works can enable you to control your genetic code and thereby silence the "bad" genes inherited and activate the "good" ones. So how do we start the chain of beneficial epigenetic changes?

FACTORS THAT MAY AFFECT OUR GENES

Although epigenetics is still in its infancy, much is already known about the ways to change the activity of hundreds or even thousands of genes.

NUTRITION. In 2003, a study at Duke University (USA) showed that nutrition not only changes DNA operation but also causes hereditary transformations[29]. Test objects were so-called agouti mice. They differ from normal mice in the more active special gene responsible for the formation of the agouti signal peptide. This protein makes animals prone to obesity, increases the likelihood of tumor development, and produces a pigment in the follicles, giving the fur a yellow color (instead of brown or black).

In the study, female agouti mice shortly before mating were "put" on a special diet rich in folic acid, vitamin B12, and the amino acids, choline, and methionine. This dietary pattern was maintained throughout pregnancy and the lactation period. Most of the young mice were born with normal color and healthy metabolic processes, with no tendency to become obese as adults. Moreover, several more generations of rodents born from the first offspring of agouti mice also showed no signs of agouti peptide activity, although they adhered to a standard diet.

Such results, experts say, are very applicable to humans as well. They state that folic acid and vitamin B12 deficiency in pregnant women leads to negative changes in methylation, which can lead to pathologies manifesting not only in the child but even in their future children and grandchildren.

A correct diet and healthy lifestyle can help silence the expression of hundreds of genes associated with cancer development. This was shown in a 2008 experiment carried out by scientists from the University of California, San Francisco[30]. For three months, men diagnosed with prostate cancer were on a low-fat plant-based diet and received vitamin and amino acid supplements. In addition, an exercise program was designed for them. As a result, patients were able to change the expression of more than 500 genes: activate 48 genes reducing tumor growth and suppress 453 genes associated with tumor overgrowth.

SPORT. Exercise at least twice a week can change the activity of several thousand genes. A study conducted by researchers from Lund University (Sweden) showed that in volunteers who regularly attended aerobic training for six months, there were epigenetic modifications in 7,663 genes associated with delayed development of type II diabetes and obesity[31].

Exercise can slow down the development of obesity, even in those who have a genetic predisposition. An international team of experts studied data from more than 200,000 patients and concluded that regular exercise suppresses the activity of 11 genes associated with weight gain[32]. Among them is the FTO gene, which increases the likelihood of obesity by 30 %.

Experts from Massachusetts General Hospital proved that increasing physical activity can reduce the risk of depression among people who are predisposed to this disorder[33]. They calculated the genetic risk for each of the eight thousand participants in the study and then surveyed how long it took them to exercise and what sports they did. Then they monitored the health of the subjects for two years.

The most active people showed a lower tendency to develop depression, even though they had a high genetic risk. The likelihood of a new episode of depression for them was reduced by 17 %.

According to scientists, four hours a week would be enough to change the expression of the right genes and protect against repeated episodes of depression. It does not matter what kind of physical activity you do: both high-intensity exercises (aerobics, machines, dancing) and moderate-intensity ones (yoga or Pilates) are good.

BAD HABITS. Tobacco smoking is one of the most powerful negative lifestyle factors that affect not only the whole body but also gene activity, "turning on" and "turning off" entire clusters of different genes. Epigenetic modifications can cause the development of many diseases: cancer, chronic obstructive lung disease, cardiovascular disease, osteoporosis, etc.

Every year more studies are proving that smoking irreparably changes the epigenetic state of human DNA. An international team of experts analyzed and compared the DNA methylation profiles of former and current smokers, as well as those who have never smoked[34]. The researchers came to the following conclusions.

● Smoking changes the activity of more than seven thousand genes – i.e., more than a third of all known protein-coding genes that make up our genome.

● In people who quit the bad habit, only five years after quitting, most DNA methylation sites returned to the levels seen in those who never smoked.

● However, there were also areas of DNA that remained with the "nicotine" tag even 30 years after quitting smoking and continued to function in the same way as active smokers.

● Most of the genes with altered expression due to smoking have been associated with numerous diseases, such as cancer and heart disease.

As for alcoholism, experts from Cambridge University (UK) proved that alcohol abuse causes irreversible changes in the DNA structure of blood stem cells (double-strand break, poor DNA repair – the function of damage repair, rearrangement inside chromosome parts), which leads to malignant tumors[35]. For example, alcohol dependence increases the risk of developing at least seven types of cancer, including the most common, breast, and colon cancer.

Numerous studies have shown that drugs, both light and heavy, are not only harmful to those who use them but also contribute to birth defects and genetic diseases in their children.

American researchers at Duke University have found a potential link between cannabis use by fathers and the development of mental illness in their children[36]. In men who used marijuana, they found several adverse changes in gene activity associated with autism, schizophrenia, and post-traumatic stress disorder. Experiments on rats showed that the born offspring had similar epigenetic changes. This confirms the likelihood of the "marijuana" tag transmission for generations. Another study by the university showed that the father's use of marijuana affects the child's cognitive functions: abnormalities were found in certain brain areas related to learning, memory, reward, and mood[37].