Washing with soap to remove the top layer of skin keeps diseases away. The main thing is not to overdo it: excessive hygiene is also harmful.
For hand washing, ordinary soap is sufficient. It takes between 40 and 60 seconds and a few simple movements». It is one of the invitations that appeared on the Ministry of Health website in the first months of 2020, when Italy also became aware of CoVID-19. Since then, the habit of frequent hand washing has spread all over the world: in fact, even if soap does not kill the germs present on the skin, it removes them by “capturing” them in micelles (formed by the soap molecules surrounding the granules of dirt) and then dragging them away when we rinse.
To wash hands. Yet, although washing hands has always been a common hygienic practice, awareness of its daily need, at least until a few years ago, was not so widespread. According to the World Health Report of 2000, when they go to the bathroom in many countries people scrub their hands with soap and water less than one time out of five (in Italy we are cleaner, see box on the right), to the point that in the countries in which general hygiene leaves something to be desired, there are still about 2 million deaths a year from forms of dysentery which, in half of the cases, could be avoided with hand washing.
And in any case the washings, according to a study published in the Journal of Environmental Health in 2013, it lasts at least 15 seconds for only 5% of people. In other cases, the average duration is six seconds for men and seven for women. There are no more recent global studies, but given the current anti-Covid recommendations these times have probably lengthened today.
The bacterial flora on the skin. In any case, despite the fact that thorough hand cleansing has been shown to keep away various diseases, there is less certainty in defining the right amount of washing that not only the hands, but our whole body must face in order to avoid disease. For example, although it is thought that «showering every day is healthier than washing less often», as argued by Robert Schmerling, associate professor at Harvard Medical School, «in reality it is a habit more linked to social norms and culture and health“. If more washing does not equal more health, in an era obsessed with germs like ours, we can also arrive at the paradox: by dint of cleaning ourselves, that is, we risk getting sick.
«A microbial flora lives on our skin which is determined by genetics for certain parts of the body; for others, however, it is also influenced by the environment (for example, the flora on the skin of the feet depends on the type of socks and shoes)», begins Antonio Costanzo, head of Dermatology at the Humanitas hospital in Rozzano (Milan) and professor at Humanitas University. «On the one hand, this surface flora has the function of a first barrier against pathogenic germs; on the other it keeps our immune system “alert” by stimulating certain cells called T lymphocytes, which are ready to respond to allergenic agents or to attacks by germs and bacteria».
Immune memory. At this point there are two choices: either we repair the damage done by the cleanser by spreading a moisturizer on the skin or, better still, we change the cleanser. After all, according to some studies, the alteration of the surface microbial flora linked to an excess of cleaning is responsible for a phenomenon that has clearly increased in recent years: the spread of skin allergies. “Since childhood, our immune system needs a certain amount of stimulation from microorganisms, dirt and other environmental factors, the so-called ‘antigens’, to produce antibodies”, explains Costanzo.
However, if hygiene is exaggerated from the first years of life, this sort of “immune memory” is also reduced, i.e. the ability to defend ourselves against elements with which we have already come into contact: «it is as if for years we had lived under a glass bell and then, faced with an allergenic agent, we weren’t “trained” to resist», explains Costanzo. «Not surprisingly, there are clinical studies that demonstrate how some nomadic peoples defend themselves better than others from allergies, to the point of almost never developing a skin disorder called atopic dermatitis. Because individuals since childhood often come into contact with various types of antigens », initials the doctor.
Skin allergies. Another theory claims that, on skin already stressed by washing, skin allergies are on the rise due to pollution, which alters the antigens so that they are unrecognizable by the immune system. Mark Holbreich, an Indiana allergist, has discovered that today’s Amish, who live as they did in our countryside over a century ago, have much lower levels of allergies, eczema and other skin problems than even their peers who live in the mountains of Indiana. Swiss.
Without soap. Not being able to move far from the cities, how can we avoid damaging ourselves from too much bubble bath? A “soft” possibility is to shorten, or even reduce, the showers: «No more than three minutes, with lukewarm rather than hot water, and soaping only the armpits, groin (but not genitals) and feet», recommends Emily Newson , dermatologist at UCLA Medical Center, University of California at Los Angeles.
After all, in those specific areas, it is not the sweat itself that gives off the stench, but the bacterial flora, which ferments the fluid produced by the apocrine sweat glands, located precisely under the armpits and around the groin. This is why, if you play sports, or sweat a lot or have oily skin, “in loco” you should use the bubble bath.
Instead, in the other areas of the body where the bacterial flora meets the secretions of the eccrine glands, which remain odourless, there is no need to soap to avoid the presence of effluvia. Finally, to protect the skin from too much hygiene, the radical alternative remains: to banish soap, shampoo and deodorant altogether. This is what the journalist and public health expert James Hamblin did, who even calculated the time that would be saved over the course of 100 years of hypothetical life if every day we no longer had to spend at least 30 minutes (between morning and evening) washing: 18 thousand 250 hours, equal to three years of extra free time. In his essay Clean: the new science of skinHamblin recounted what happened to his body when he started washing with water alone five years ago.
“At first I was an oily and stinky beast,” he writes, recalling the phase in which the bacteria on the skin, finding a more greasy surface available, produced more bad smells. But slowly her bacterial flora rebalanced, «the skin became less oily, I reduced the eczema and even under the armpits the smell became less pungent than when I skipped the deodorant for a day». This is obviously an excess, but the conclusion of Hamblin’s experiment (who still has a girlfriend and a social life) is that, to protect skin and health, it is necessary to focus on scientific evidence. One of them, for example, “is that washing only with water does not make one perfumed, but it does not damage the skin”, concludes Costanzo.
[Articolo tratto dagli archivi di Focus]