BLOG

The well-known phrase “skin deep” is used to describe something that is seen as superficial or meaningless. While our skin is the body’s second largest organ (the gut has the largest surface area), it is often thought to be taken care of solely to benefit one’s outward appearance and to enhance both our beauty and youth. The goal to have a glowing complexion and reduce fine lines and wrinkles are often minimized to vanity concerns. Some may see these concerns as “skin-deep,” but the role that the appearance of the skin plays in our health and well-being is often overlooked.

Many researchers and clinicians specializing in dermatology are suggesting that the appearance of the skin may be more than just a surface level concern. The more the skin begins to break down with age, so does the rest of the body. In addition to preventing fine lines and wrinkles, anti-aging skincare could have the power to go beyond outward appearances. Taking care of the skin topically can help increase the vitality our internal organs. These emerging studies are finding that taking care of the skin not only mirrors signs of aging but also contributes to it.

Inflammatory skin conditions can affect the entire body and this can easily been seen in the case of psoriasis and eczema. These conditions both result in problems with the function of the epidermis, the outer layer of our skin, that serves as a protective barrier. The epidermis ensures the body retains fluids necessary for survival and optimal cellular function. If this outer layer is severely damaged, it is no longer able to function as a protective barrier, causing a severe health risk that can ultimately result in death.

When the epidermis is damaged, the skin cells try their best to repair the barrier. In their attempt to do this, they are releasing cytokines which are chemical signals that trigger inflammation. Short-term inflammation is an adaptive transient response that ultimately promotes healing. However, inflammation becomes a problem when it becomes chronic, which is the case in psoriasis and eczema. This chronic inflammation leads to elevated cytokine levels in the blood, and overtime can lead to conditions such as accelerated cognitive decline, arthritis, muscle and bone loss, and type 2 diabetes.

Research also suggests that Inflammatory Bowel Disease often is associated with inflamed skin. Richard Gallo, MD, PhD, is a leading physician and researcher at the University of California, San Diego (UCSD) Department of Dermatology. Gallo conducted a study in 2021 that explored chronic gut inflammation in IBD and inflamed skin are associated with one another. They studied mice and showed that when the skin became inflamed, it released a chemical called hyaluronan that signals to the gut-associated immune system, triggering mucosal inflammation which contributed to IBD.

“…when the skin became inflamed, it released a chemical called hyaluronan that would then enter the gut and send signals to the immune system, triggering inflammation which contributed in IBD.”

The damage that inflamed skin can cause to the brain is cause for concern as there has been a strong association between cognitive impairment in older adults and damaged skin. Studies have found that chronic inflammatory skin conditions are often linked with dementia and Alzheimer’s as prolonged inflammation can predispose to accelerated aging. Additionally, the risk of cardiovascular disease is also increased by eczema according to a meta-analysis of 19 studies. While the correlations are small, there is a significant link between chronically inflamed skin and risk of heart attack, stroke, and even heart failure. People with these chronic skin conditions, such as eczema and psoriasis are at higher risk than those who do not have skin conditions, demonstrating a strong association between internal health and inflamed skin.

“Studies have found that chronic inflammatory skin conditions are often linked with dementia and Alzheimer’s as prolonged inflammation may result in accelerated aging.”

So, what can be done to protect the skin barrier? Theodora Mauro, MD, is a practicing dermatologist at the University of California, San Francisco (UCSF) whose research looks at how the epidermis functions, specifically in aging skin. Mauro teamed up with Peter Elias, MD, and Mao-Qiang Man, MD, who are also research scientists in the UCSF Department of Dermatology, to study how the barrier of the skin of mice responded when damaged and restored. When damaged, the cytokine levels in their blood rose, but when the skin barrier was repaired with a topical application of glycerol, the cytokine levels fell.

The key finding here may be that it is crucial to keep water inside the stratum corneum, the outermost layer of the epidermis. Elias and Man led another study in 2023 that evaluated the skin and blood of 255 adults who were 65 years or older. Their findings showed the participants who has less water in the stratum corneum had higher levels of cytokines in their skin and blood.

Researchers are also beginning to understand the important role that the skin’s microbiome has on the immune system, and how a healthy microbiome can enhance the skin’s barrier. Species of bacterium such as Staphylococcus aureus can become infectious and a healthy skin microbiome is protective against such infections.. This facultative pathogen competes with beneficial bacteria such as beneficial Staphylococcus strain S. hominis. People with eczema have less of the beneficial bacteria, meaning the harmful bacteria can take over and drive inflammation, showing that a healthy skin microbiome is key.

The solution seems clear—improve skin health and as a result, this will reduce risks of conditions that become more common with aging such as dementia or cardiovascular disease. As aging skin drives inflammation, topical anti-aging skin treatments could help to counteract this. However, more studies are still needed to provide strong evidence of this hypothesis. While the study results to support such a claim are promising, they have to be considered pilot studies. Additionally, there’s still various external factors that need to be taken into account in order to provide more concrete evidence. Factors such as ethnicity and the relative benefits of different treatments for barrier repair have to be taken into account.

“As aging skin drives inflammation, topical anti-aging skin treatments could help to counteract this.”

One ingredient that skin experts currently recommend is glycerin, which can be found in many skin care products and lotions. Glycerin acts a humectant, a substance that pulls water from the air and draws it into the skin, resulting in hydration and minimizing water loss. Glycerin has been shown to improve barrier function, so lotions containing this ingredient could be a good choice for those looking to protect the skin barrier. In addition to topical products, lifestyle choices can also go a long way. Reasonable amounts of sunlight exposure are great for vitamin D levels, as long as overexposure is avoided and there is no risk of sunburn and UV-induced skin damage. Additionally, staying hydrated and eating a diet rich in nutrients can help benefit the health of the skin.

It is commonly thought that the skin reflects how well we take care of our internal health. For example, many of us have been advised to avoid smoking cigarettes as it causes wrinkles, or to eat a diet rich in Omega 3’s to keep the skin’s appearance looking full and youthful. People even supplement with collagen in hopes of increasing and protecting their own collagen stores. While all of these interventions do have an effect on the skin, the relationship between the health of our skin and the health of our internal organs appears to be a “chicken or the egg” situation.

Mauro states that due to the amount of crosstalk between our various bodily systems, it is difficult to determine what is driving the process, and both the internal and external effects are likely at play here. The immune cells that live in the skin are essential driving forces of systemic health, so the way in which these cells are affected on the outer level, will have an effect on our inner levels of inflammation. While more research is needed, both viewpoints are correct, meaning the skin not only mirrors our internal health, but also influences it. The way we care for our skin has effects that go beyond “skin deep.”