Weighing up to 10% of our weight and measuring 2m ², the skin is far from the most difficult and the biggest organ of our body. It serves as a protective cover for our body, the skin allows us to discover the warm and cold, helps us to regulate our internal temperature, but also to breathe and feel.
However, despite the importance of these functions, scientists have never before considered the skin as an organ capable of protecting us from the onset of chronic illness.
This is now done with this pilot study conducted by researchers at the University of California at San Francisco (UCSF). Posted in Journal of the European Academy of Dermatology and VenereologyThese new studies are the first to study the role of skin in the development of chronic age-related conditions, including type 2 diabetes, atherosclerosis, Alzheimer's disease, and osteoporosis.
The older the skin, the more it is permeable to the pathogens
As we age, the level of inflammation increases in our body. Included: molecules called cytokines. Especially secreted by lymphocytes B, they stimulate cells responsible for the development of immune defense, but they can also contribute to the development of autoimmune diseases or chronic inflammatory diseases.
For a long time, scientists believed that the immune system or liver cause inflammation. These new studies show that skin can play an important role. "Inflammation must come from an organ large enough for very little inflammation to affect the entire body, and the skin is a good candidate for it because of its size," says Dr. Mao Qiang Man, chief author. from the study and researcher at the UCSF Department of Dermatology.
"Once we get older, we have dermatological symptoms like itching, dryness and changes in skin's pH". It may be that the skin has very little inflammation, and because it is an organ, so great, it increases the circulating levels of cytokines, "he continues.
Indeed, with age, it's not uncommon for the skin to become dry and therefore more suitable for pathogens: reducing the moisture of the dermis causes small cracks that cause the release of cytokines in the blood.
In younger skin, these cytokines released into the blood help repair cracks in the skin. Mature skin, on the other hand, is more difficult to repair: the body continuously releases these inflammatory ambassadors who, once released into the blood, can travel through the body.
"Until recently, the scientific community did not believe that the skin could contribute to inflammation and systemic disease, but in the last five years, studies of psoriasis and dermatitis have shown that skin because of these diseases probably increases the risk of heart disease," says Dr. Theodora Mauro, co-author of the study. According to her, "the simple reduction of inflammation by treating dysfunction of the skin observed during aging can have profound effects on health."
Bind your skin to reduce inflammation
To confirm or not this hypothesis, researchers have committed to measuring the impact of skin aging on inflammation. They also looked at whether they can reduce the signs of inflammation by moistening the skin.
The pilot study included only 33 participants aged 58 to 95, but showing encouraging results. The researchers measured their cytokine levels at the start of the study, and then, for 30 days, participants applied cream every day. Formulated specifically for the experiment, this cream contains three types of lipids: cholesterol, free fatty acids and ceramides.
After this period of study, researchers measure changes in their levels of three cytokines that have links to adult-related inflammatory diseases: interleukin-1 beta, interleukin-6, and tumor alpha-necrosis factor. They found that the levels of these three cytokines in the blood significantly decreased after the hydration period. According to them, the observed rates correspond with those of the people in their thirties.
Because this experiment used a particularly small sample, the researchers would have to conduct new, larger investigations in order to draw reliable conclusions. They will also need to show that reducing cytokines in the blood has important long-term health benefits.
Are you interested in this topic? Come and talk about it on our forum!