English Version | Smelly season

You can't see it. Sometimes you can't even feel it. But you can smell it. Sweat is as ubiquitous in summer as an ice cream vendor on an afternoon at the beach. Yet some people are oblivious to its most unwanted consequences. For the sake of a silly season that is pleasant to the sense of smell, breathe it in, and sweat it out.

It is the biggest enemy of gray t-shirts, a silent killer on public transportation, and, after death, probably the second greatest certainty of life. I sweat, therefore I am: few dare to say it, but everyone feels it. It is impossible to separate the human body from this process inherent to its functioning. As unpleasant as perspiration may be, its absence would cause even greater difficulties in our lives. "Sweating plays a very important role in maintaining body temperature. When we sweat, for example, in the context of physical exercise, hard work, high temperatures (...), the sweat on the surface of the skin evaporates, cooling the body and thus reducing the excessive heat produced", explains Paulo Morais, dermatologist at Hospital da Luz, in Amarante. Add sweating to the endless list of negative externalities of climate change: the higher the temperatures, the greater the volume of sweat per cubic meter. However, an external heat source is not always necessary - the most ubiquitous disease of the 21st century also has a role to play. Júlia Vide, a dermatologist at the Prof.ª Sofia Magina clinic in Porto, adds: "Stress also stimulates sweat production, especially palmoplantar [on the palms of the hands and soles of the feet], which allows you to hold objects without slipping and perform delicate tasks with your fingertips. This emotional sweating is triggered by the sympathetic nervous system."

Sympathetic, after all, is sweat, which is not only essential to human survival but also contributes to the performance of everyday tasks. And even in matters of smell, we may have blamed the wrong villain. "Sweat (...) is practically water (99%), the remaining components being ions, such as potassium, chloride and sodium, ammonia, lactic acid, urea and other substances", details the dermatologist at Hospital da Luz. Like water, sweat has no odor. So where does the unpleasant smell that common sense has taught us to fear come from? Paulo Morais clarifies: "In the skin, there are bacteria that break down some components of sweat, producing by-products with an unpleasant odor." "It's not the sweat that has an odor, it's its contamination by bacteria," summarizes Júlia Vide. This explains why perspiration in certain areas, such as the palms of the hands, does not manifest itself in the same way as perspiration in the armpits, for example. There are two main types of sweat glands in the human body. Eccrine sweat glands "are the most numerous, found all over the body, particularly in the palms of the hands, soles of the feet, frontal region and armpits", says Paulo Morais. According to dermatologist from Prof.ª Sofia Magina clinic, apocrine sweat glands "are concentrated in hairy areas such as the armpits, genital area and scalp and are activated during puberty." "The amount of sweat from the apocrine glands is much smaller than the amount of sweat from the eccrine glands, but its composition, rich in proteins and lipids, attracts bacteria that are responsible for the formation of the unpleasant odor associated with sweat and its coloration", says Júlia Vide. In addition to behaving differently from each other, the action of the sweat glands can vary depending on the body and the context in which they are found. "Inter-individual variations are due to genetic factors, which determine the number of sweat glands in our body and its distribution, and environmental factors, namely physical activity, climate, stress, hormonal changes such as puberty, pregnancy or menopause and some metabolic diseases (diabetes mellitus, thyroiditis)", informs the dermatologist from Porto. This explains, among other things, the amount of sweat produced by each person. In the words of Paulo Morais, "the rate of sweating is proportional to the metabolic rate", that is, the energy expended by the human body. "In general, a medium-sized adult eliminates between 0.5 and 2 liters of sweat per hour during physical activity. Active or hard-working adults can sweat a maximum of 15 liters per day, depending on the level of activity and temperature."

Excessive sweating only occurs when it exceeds the amount needed to regulate body temperature, a condition known as hyperhidrosis. "Hyperhidrosis is a relatively frequent pathology" which, according to Paulo Morais, affects "about 3% of the population." Although it does not have health consequences, it can negatively impact the quality of life of individuals, particularly in the "psycho-emotional, social and professional” fields. The dermatologist explains that excessive sweating can lead patients to "avoid physical contact, such as shaking hands, and participating in recreational and sporting activities", as well as having "difficulty holding tools, using a computer keyboard or driving." "If sweating suddenly changes pattern, especially in quantity or circadian rhythm, or if associated with other symptoms, it is important, before carrying out any treatment, to consult a general doctor, a dermatologist or an endocrinologist to exclude systemic diseases", says Júlia Vide. After diagnosis, the most appropriate treatment will be selected for the identified case.

In addition to clinical procedures, recommended for more extreme conditions, there are products that anyone can use to minimize the negative consequences of sweating. Most will be familiar with them, even if their names can be confused. In today's market, they fall into two categories: deodorants and antiperspirants. For the dermatologist at the Profª. Sofia Magina clinic, deodorants "minimize the bad odor associated with sweat due to their antibacterial effect, achieved by combining different ingredients and active components." In turn, "antiperspirants are formulated with aluminum hydrochloride and other aluminum salts, which block the ducts of the sweat glands, acting as perspiration inhibitors. These products are ideal for people who want to reduce the moisture caused by sweating or suffer from hyperhidrosis," advises Paulo Morais. Due to their blocking action, antiperspirants also reduce body odor. However, to maximize their effectiveness, the dermatologist offers a suggestion for use: "Antiperspirants should be applied at night, before going to bed, to block the ducts of the sweat glands at a time when our metabolism is less active. For extra protection, a thin layer of antiperspirant or deodorant can be applied in the morning." 

There's a word in the previous paragraph that may have set off alarm bells. Aluminum is one of the most controversial ingredients on the cosmetics market today, and its effects on human health have been studied in depth. Among the most alarming claims is an alleged link to breast cancer. However, according to the dermatologist from Porto, this is not a justified concern: "To date, there is no sustained scientific evidence linking the use of antiperspirants containing aluminum salts and an increased risk of breast cancer." Paulo Morais expresses the same conviction: "Cancer specialists and Health authorities, including the US Food and Drug Administration (FDA) and the European Commission's Scientific Committee on Consumer Safety (SCCS), consider that, to date, evidence and data capable of confirming this relationship have not been presented, and there is no convincing scientific evidence that the risk of breast cancer increases with the use of antiperspirants containing aluminum salts, which are considered safe for human health."

Because of this controversy, numerous alternatives to conventional antiperspirants and deodorants have sprung up, replacing the most alarming components with natural ingredients. Although some have been more successful than others, the general belief is that these alternatives have not yet been able to match the effectiveness of conventional products, particularly those composed of aluminum. Still, the two experts interviewed by Vogue Portugal listed a set of habits that, along with the application of the desired products, can help minimize body odor. Hygiene habits are among the most important. Paulo Morais advises "taking a daily shower with warm to cold water, using a hygiene product (such as soap or shower gel) with antiseptic or antibacterial action and drying the skin completely", since bacteria tend to thrive in humid environments. Another recommendation from the dermatologist is to "keep the armpits shaved, especially in summer, to help evaporate sweat and reduce the odor caused by bacteria." Júlia Vide explains that "there should be given preference to loosen cotton clothing, avoiding synthetic fabrics that are not very porous." In addition, the dermatology specialist advises against the consumption of "drugs, alcohol, nicotine and coffee, as well as spicy or very hot foods", as they can affect the amount of sweat produced. Those who are particularly bothered by perspiration on their feet should "wear breathable shoes and moisture-wicking socks, changing them whenever necessary during the day", and may also opt for insoles that absorb sweat, according to the dermatologist at Hospital da Luz. "In the common sense, there are those who use the alum stone to reduce sweating, and milk of magnesia and roses to avoid the bad smell of the armpits. In summer, applying compresses with black tea can help reduce sweating, due to the presence of tannic acid," adds Paulo Morais.

When maintaining these habits is not enough to minimize the smell and the amount of sweat, it is possible to resort to clinical treatments. In Júlia Vide's experience, in cases of excessive sweating, the dermatologist recommends "for the armpits and/or groin the application of botulinum toxin and for the palms and/or soles iontophoresis. In my opinion, these are the safest and most effective treatments for severe cases, with great satisfaction from patients." In addition, Paulo Morais suggests therapeutic options such as "oral medications (e.g. oxybutynin), eliminating sweat glands through thermal energy (MiraDry system), radiofrequency or liposuction, or interrupting nerve impulses to the sweat glands by performing an endoscopic thoracic sympathectomy." The treatment should be selected on the recommendation of a specialized doctor, as each case is unique and requires differentiated care. However, in the face of such a wide range of options, there is one message that needs to be reinforced: no one has to suffer from sweating. Today, there are effective products and procedures with the ability to minimize the amount of sweat produced and the associated body odor. All that remains is to demystify perspiration, which is common to all human beings, and approach it with the same normality that is inherent to it. Because this season is meant to be silly, not smelly.

Translated from the original on The [Un]Popular Issue, published July 2023.Full stories and credits on the print issue.