TOKYO - As temperatures rise, concerns about body odor return, drawing attention to a lesser-known scientific field that examines the invisible gases emitted from human skin, with Tokai University professor Yoshika Sekine leading research that could even help detect disease and stress levels.
From the fleeting scent left behind by someone rushing onto a train to the stronger odors that come with age, body odor is something people of all generations are conscious of. While often dismissed as unpleasant, scientists are now uncovering that humans emit a variety of scents, including those linked to fatigue, lack of sleep, and even dieting.
At the center of this research is the concept of "skin gas"—trace amounts of invisible gas released from the surface of the body. Unlike skin respiration, this process involves the emission of odor-related substances as the body expels compounds through multiple pathways.
Sekine explains that skin gas is produced through three primary mechanisms. The first involves sweat, which is originally odorless but develops a smell when broken down by bacteria on the skin’s surface. The second occurs when substances circulating in the bloodstream transfer into sweat and are released through the skin. The third involves compounds absorbed through food that travel via the bloodstream and are emitted directly through the skin.
For example, eating garlic initially causes bad breath, but that smell fades relatively quickly. However, compounds released through the skin persist longer, resulting in a lingering odor that continues even after returning home.
Because skin gas is emitted in extremely small quantities, it has historically been difficult to measure. Sekine and his team developed specialized equipment to capture and analyze these gases, isolating odor components and identifying their sources. This has led to the discovery of new types of body odor and their classifications based on origin.
Among these, so-called "aging odor" has drawn particular attention. Typically emerging in men from around the age of 35, it is linked to sebum, or skin oil. Although oil production decreases with age, the composition of these oils changes, resulting in stronger, more noticeable odors over time.
The implications of skin gas research extend far beyond hygiene. According to Sekine, analysis of skin gas may allow for early detection of diseases such as cancer, as measurable differences have been observed between patients and healthy individuals. In addition, certain compounds increase when a person feels sleepy or fatigued, offering potential for monitoring physical and mental states.
The research also suggests that emotional experiences can influence body odor. Watching an enjoyable movie, for instance, can increase the emission of pleasant, fruity-scented compounds, highlighting a surprising link between mood and scent.
As scientists continue to explore this emerging field, skin gas is gaining recognition not just as a source of body odor, but as a valuable indicator of health, lifestyle, and emotional well-being.
Source: テレ東BIZ
