In a meeting of former colleagues, the reunion after so many years makes comparisons inevitable. At Gabi, we appreciate some overweight. Irene, much thinner, complains of intestinal discomfort. Zoilo moves with some difficulty. Andrea dances non-stop, without a doubt she retains the vitality of “her young years”.
There is no doubt that time affects everyone differently. But are there genetic causes? Can we predict the way we age?
In 2020, a news story about aging went viral. It came from California, from Michael Snyder’s lab. A team of nine geneticists had analyzed deep molecular patterns in 106 people for four years, taking samples every three months. Some aged quickly, others slowly, and others improved in some respect over the years.
With the collected samples, they made a molecular profile of each individual. In each person they found specific molecular markers. In view of the results, Snyder described four basic ways of aging:
The metabolic type, which is characterized by deficiencies in the processing and detection of nutrients. And it is prone to diseases like diabetes.
The immune type it tends to affect its immune system, which weakens earlier and that makes it easily inflamed.
The liver types Y nephrotic, that present dysfunctions in the liver or the kidney, respectively.
According to Snyder, in the future these four ageotypes could guide treatments, favoring a more personalized medicine. In his understanding, if we detect which parts of our body age faster, we can use drugs to slow down the process.
However, it is still too early to launch the bells. Aging processes are complex, because they encompass genetic mechanisms (telomere wasting, DNA instability), cellular processes (mitochondrial dysfunction, cellular senescence, and others), and functional aspects (inflammation and stem cell depletion).
Perhaps too complex to be pigeonholed into just four ways of aging.
What is getting old?
Aging is a gradual, spontaneous process. It begins from the moment we are born, continuing throughout life, and involves the progressive decline of motor, intellectual and physiological skills. The changes that accompany this process are, today, inevitable.
The amount of changes that occur in our body as we age is tremendous. The skin becomes thinner and loses elasticity, wrinkles appear, the hair turns gray and tends to fall out, the density of the bones decreases …
Simultaneously, reflexes and sensory acuity decline, especially in sight and hearing. The heart pumps less blood, the lungs have less capacity, the reproductive system undergoes variations in hormone levels, and the central nervous system is affected. In addition to other internal organs can also suffer dysfunctions.
As for the brain, normal aging implies a small brain atrophy (smaller brain size), loss of certain types of neurons, decreased neurogenesis (ability to generate new neurons), as well as the accumulation of harmful substances.
Likewise, there may be changes in the production of hormones and neurotransmitters, affecting neuronal connections and the ability to form new connections.
Chronological age versus physiological age
This is what, broadly speaking, is getting old. However, we do not all go through the process in the same way. There are people who age better than others.
That is why we distinguish between chronological age, which is the one that appears on the DNI, and biological age, which indicates our physical and mental state. People who do not seem to age, who “wear better the years”, have a similar biological age than the chronological age. This has been called successful aging, as opposed to pathological. The reason, however, is not yet clear. But it could be due to a multitude of factors, both genetic and environmental.
What seems indisputable is that aging is closely linked to the appearance of diseases, the incidence and severity of which increase with age.
We are at the beginning of the road. We have begun to understand the root causes of aging, but the molecular basis of aging is not well understood.
As for ageotypes, they have important shortcomings. For now, psychological and emotional factors are out of the equation. And some ageotypes have yet to be defined, for example the one related to cardiovascular vulnerability.
The good news is that, whatever our ageotype, there are a series of activities and daily habits common to the entire population that stop aging. The recipe is none other than to control chronic diseases – especially cardiovascular and diabetes -, practice physical exercise, bet on cognitive stimulation, maintain social relationships, avoid the consumption of harmful substances and opt for a diet low in empty calories.
If we commit ourselves to a healthy lifestyle, the crystal ball will announce more years and, above all, greater well-being and quality of life.