Until now, most of the studies that analyzed the biological clocks of our body were based on hormones, telomeres or saliva. Now, at the University of California (UCLA) they have taken a further step in the world of gerontology, studying the way our DNA changes over time, a kind of biological clock inside our genes.
” To fight aging, we first need to come up with an objective way to measure it . Locating the set of time-marking biomarkers throughout the body has been a four-year challenge,” explains Steve Horvath, Professor of Human Genetics at the School of UCLA Medicine and Biostatistics at UCLA Fielding School of Public Health. ” My goal in getting this age predictive tool is to help scientists improve their understanding of what speeds up and slows down the human aging process.”
To create this predictor Horvath focused on DNA methylation, a chemical process that modifies our genes. Thanks to some 8,000 samples of 51 different types of tissues from different parts of the body, the researcher analyzed how this process affects aging, from birth to 101 years of age. Focusing on 353 markers, he verified how this methylation changes with age throughout the body. Later he analyzed the effectiveness of the tool by comparing the biological age of a tissue with its chronological age.
Although most tissue samples showed a correlation between biological and chronological age, others did not. For example, Horvath found that the age of a woman’s breast tissue was much older than that of the rest of the body. “ Healthy breast tissue is two to three years older than the rest of a woman’s body. But if a woman suffers from breast cancer, the healthy tissue that surrounds the tumor is an average of about 12 years older than the rest of the body ”, explains the researcher.
These results could explain why breast cancer is the most common among women, in addition to the influence of age as a risk factor for many types of cancer in both sexes.
In addition, the research looked at the importance of stem cells in the aging process. “Research shows that all stem cells are newborns,” explains Hovarth. “More importantly, the process of transforming a person’s cells into pluripotent stem cells resets the cell clock to zero.” In principle, this discovery theoretically proves that scientists can reverse the body’s biological clock and reset it .
However, this aging process is not as fast at all ages. According to the study carried out at UCLA, the pace is much faster until adolescence and from there it decreases slowly until the age of 20 is reached.
The study has been published in the specialized journal Genome Biology and the university itself has already applied for a provisional patent for this tool for predicting the age of tissues.
