If you think of age in terms of years, then it is one-way. People have a biological age in addition to their chronological age, which confounds scientists. Age over the years is simply a number, as you may have discovered when you encountered an 80-year-old who was in much better form than you or a 20-year-old who appeared to be in his 40s.
The word “biological age” is a concept used by scientists to describe how well a person’s body and cells function. The majority of the time, your health is better the younger your biological age. Additionally, there are numerous everyday actions that can be taken to delay biological aging, in contrast to chronological age, which cannot be altered.
According to researcher Jesse Poganik, chronological age is only a number on a passport but biological age indicates the age of our cells. The biological age of the cells decreases as they perform better and more effectively. The biological age of the cells will be higher if they are aging more rapidly.
On the basis of biomarkers produced as a person’s DNA changes over time, scientists can determine a person’s biological age. DNA methylation, an epigenetic alteration in which methyl groups are introduced to cellular DNA, is the source of one biomarker. A stable molecule known as a methyl group is made up of a carbon atom linked to three hydrogen atoms. Although generally unresponsive, these groupings can have a significant impact on cellular function. Cell function may decline as methylation progresses, increasing biological age.
By developing a predictor that can determine the DNA methylation age of numerous tissue and cell types, a 2013 study demonstrated the connection between ageing and methylation. The epigenetic clock, named after the author Steven Horvath, has been utilized in numerous studies. They gather details on DNA methylation in specific parts of the genome, which may be tracked by researchers. Poganik pointed out that it is feasible to precisely determine the biological age using different algorithms and combinations of these timepieces. The data from these biomarkers, he continued, is “mathematically converted” to correspond to calendar years, but the measurement is “in some ways artificial.” One biological year represents a concept that science is still working to fully understand.
The primary distinction between chronological and biological age is that only the latter is documented. Chronological age and biological age frequently diverge. There are stressors that, since stress spreads at the cellular level, such as the birth of a child or serious surgery, can add years to biological age.
According to Vadim Gladyshev, a professor of medicine at Harvard Medical School, the cause of ageing is molecular damage. They aren’t always permanent though. Damage and biological age both decline as soon as the body heals.
Gladyshev and Poganik discovered that bodily changes can alter a person’s biological age. A young mouse and a senior mouse were surgically paired in a process known as heterochronic parabiosis. Their circulatory systems worked together to circulate blood around each other’s bodies as a result. Due to exposure to the blood of an older mouse, the biological age of the younger mouse in this pair noticeably increased. The biological age of the youngest mouse was then reset to its pre-surgery baseline after the mice were once more separated and recovered.
Dehydroepiandrosterone, metformin, two diabetes medications, and recombinant human growth hormones were shown to have a significant impact on biological ageing in a 2019 study. After one year of treatment, the biological ages of nine experimental participants decreased by two years compared to their baseline ages, and this effect persisted for six months after treatment was stopped.
However, a 2021 study discovered that healthy habits, such as regular exercise, a nutrient-rich diet, and regular sleep, are the greatest ways to manage biological age in daily life.