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].
ENVIRONMENT. One of the factors that certainly affects gene expression, and thus our well-being, is air quality. Experts from Monash University in Australia proved that even short-term exposure to polluted air adversely affects the activity of six genes responsible for the severity of oxidative stress and inflammatory reactions in the body[38]. The "abnormal" methylation profile that was found in these DNA regions was associated with the development of dangerous cardiovascular, respiratory, and cancer diseases, as well as an increased risk of premature death.
CONTACT WITH PESTICIDES. Many recent studies have examined the effects of chemicals on gene expression, and several toxins have been identified that leave epigenetic tags in DNA. These are bisphenols in plastics and epoxy resins, phthalates in vinyl floors, plastic, perfluorochemicals used to create non-stick coatings on cookware, pesticides, herbicides, salts of heavy metals, etc. Russian scientists from the Institute of Experimental Medicine of the RAS conducted an experiment, the results of which showed that the introduction of a single dose of bisphenol into a pregnant female mouse disrupts the methylation profile of several DNA regions, which causes problems in fetal development[39].
Significant epigenetic modifications can be caused by vinclozolin. This was proved by American scientists from the University of Nebraska-Lincoln and Rutgers University (USA) and showed another good example of epigenetic imprinting[40]. In the experiment, pregnant rats were given vinclozolin in their food and observed how it would affect their babies. It turned out that male children had problems with sperm quality and quantity as they got older. And this effect persisted for four generations of laboratory animals and then disappeared.
STRESS, RELATIONSHIPS, THOUGHTS. Not only "clear" signals, such as food or toxin exposure, can change gene expression. Even the way a person thinks and feels affects gene activity. Genes very quickly respond to prolonged stress, constant anxiety, fear, arguments, and anger. They start a chain of adverse biochemical processes in the body, leading to disease development. But it is important that our genes also respond with a positive "reaction" to showing gratitude, love, and optimism.
A team of experts from Ohio State University (USA) conducted a study to find out how an ordinary family argument can affect the rate of wound healing, an important indicator of genetic activity[41]. Scientists gave slight injuries on the skin of all participants and monitored the rate of healing by the levels of three proteins responsible for tissue regeneration. During the first visit, the couples had to talk about any pleasant topic, and during the second visit, they had to remember their last unresolved argument. It turned out that after a family quarrel, spouses' wounds healed more slowly and the levels of produced proteins responsible for healing were lower than after a pleasant conversation. And in the most hostile couples those who argued with mutual recriminations, humiliations, and accusations the injuries took even longer to heal than in partners who were less hostile to each other. With thoughts and emotions alone, the spouses were able to induce appropriate epigenetic changes.