It is said that the human being loses about 100 hairs from his head per day. This is normal and in most people those hairs grow back. Now, when that hair is not “replaced”, or the person loses body hair in other areas of the body such as arms, beard, or eyelashes, it may be a health problem.
It is known as alopecia to the absence or loss of hair in the areas that normally have it. It can be a temporary or permanent problem, and among its causes, specialists list stress, hormonal changes, some medical conditions, a normal consequence of aging, or genetic reasons.
The good news for genetic alopecia, apparently the most difficult to solve, comes from US researchers, who found that humans today have the genetic information from the layer of body hair that covered their bodies millions of years ago. years, and that man lost due to the evolution of the species.
The studypublished in the magazine eLife, compared the genetic blueprints of humans with those of 62 other mammals, including elephants, manatees and armadillos, and examined how hairlessness evolved in different species at different times. The work also identified new genes and gene regulators related to body hair.
For the researchers, the discovery, which came at a time when sequencing technology is advancing rapidly and allowing scientists to read long DNA sequences more quickly and accurately, could one day be used to treat alopecia.
“It is likely that hundreds of genes have been involved in the loss of most of our body hair,” said Nathan Clark of the University of Utah, who conducted the study with Amanda Kowalczyk and Maria Chikina at the Carnegie Mellon University in Pittsburgh.
According to what the authors of the work saw, through the use of computer tools, although genes for full body hair coverage remain in the human genetic codethey were silenced.
“The initial hair loss in many species was probably very adaptive,” Clark said, referring to, for example, mammals such as dolphins, whales or manatees, which would see their swimming slowed down greatly with a body covered in hair.
In the case of humans, one theory holds that loss of body hair proved advantageous for hunting in hot climates. Less hair, along with the development of a system that allowed the body to cool itself through sweat, may have been key changes that enabled humans to become better hunters, able to pursue some prey to exhaustion.
For researchers, finding genetic changes common to many animals that have lost hair may be the solution to the problem of hair loss in humans. It is that, as they explained, “despite very different appearances and behaviors, humans share a large part of their DNA with other mammals: 99% with chimpanzees, 85% with mice and 80% with cows.” ”.
“I think this is a very powerful finding,” said Peter Sudmant, an assistant professor in the department of integrative biology at the University of California at Berkeley, who did not participate in the study. And he expanded: “These types of discoveries are incredibly cool. We are looking at 75 million years of evolution. The fact that you can look at the molecular pathways that influence a trait like body hair is mind-boggling.”
consulted by infobaethe trichologist dermatologist Miguel Marti (MN 129.557) explained that “Most alopecias have a genetic load”. “What manifests as a symptom is in the genetic base; Genes are responsible for, at one point in a person’s life, developing androgenic, areata, and frontal fibrosing alopecia, to name a few,” explained the specialist, a member of the Ibero-American College of Dermatology (Cilad) and the American Academy of Dermatology. (AAD, for its acronym in English). In androgenic alopecia, for example, it is known that there are more than 400 genes involved; It is something much more complex than what is believed”.
And after highlighting that “today there are innovative studies that postulate the genetic explanation of frontal fibrosing alopecia, a disease that was largely forgotten and had a great impact in the last ten years”, Marti assured that “today it is known that, although there is an external factor that triggers these genesthe genes are also in charge of manifesting or not the disease”.
In her turn, the trichologist dermatologist Vanina Gegdyszman (MN 144,999) observed that “in its evolution, the human species has been losing body hair, and in recent times the hair on the scalp has also decreased.”
In the opinion of the medical director of Vhair, capillary medicine, “alopecia is seen more and more in younger people, and in most of these cases genetic predisposition is involved, although in recent years, lifestyle is surely responsible for these genes being expressed at earlier ages.
Regarding the present study, the specialist pointed out that “there are cells called totipotent cells, which in her information continue to have that possible expression of hair.” “If the person does not have a genetic predisposition to alopecia, it is rare for them to express this symptom, and in these cases, having this information is useful for prevention,” explained Gegdyszman, for whom the recent find “gives hope for the future”. “Hopefully the solution is in the genes,” she said.
“It’s a matter of ‘unlocking’ those genes at the laboratory level, through gene therapies”, he evaluated, while pointing out that “in the field of trichology, the investigation of how to regenerate a hair follicle de novo is constant, and in the meantime, there are a variety of treatment alternatives according to each case and as always in medicine , the sooner the problem is addressed, the better prospect of a solution it will have”.
In this sense, according to Marti, “a great advance in recent years is the therapeutic action based on gene sensitivity; There are laboratories that do genetic tests, which although they are not as sensitive even because they are quite new, what they seek is to find out what is the genetic defect that the person presents in order to correct it through a pharmacological action that inhibits or represses that gene. that is manifesting.”
“Today, there is a new range of drugs against alopecia areata known as the antijakwhich inhibit an enzyme that is released from a gene, with the aim of temporarily resolving or correcting -while the medication is being used- the expression defect, which would be the manifestation of alopecia areata”, the trichologist added, who explained that “these treatment options are based on physiopharmacopathology depending on the disease-gene relationship.”
And after considering that “this therapeutic action, which seeks correct the disease from the genetic defect it will be the basis of most medical treatments in the future and promises a more sophisticated and technological medicine”, Marti concluded: “There is a long way to go, perhaps in about 15 years we will be able to talk about this type of treatment carried out in a more massive”.
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