Explained: Why some moisturizers may do more harm than good to your skin

New Delhi: A lot has been said about skin care products, especially when it comes to moisturizers. For instance, earlier researchers at UC San Francisco found that moisturizing your skin might reduce the risk of developing a range of health conditions, including diabetes, heart disease, and even Alzheimer’s disease. Now, a new study warned that moisturizers and other beauty products may be doing as much harm as good, especially if you have sensitive skin.

The new study by the UC San Francisco dermatology professor Peter Elias, MD, found that moisturizers may actually be turning your skin into ‘Swiss cheese’, which is not what you want. The dermatologist said his patients acknowledged that moisturizers provided only short-term relief, as the skin would feel drier in the long term. To find out more about how lotions affect the skin or whether the moisturizers play a role in ‘Swiss cheesing’ of the skin, he developed a model of the skin called corneocytes, which are composed of dead cells that form the outermost layer of the epidermis. Those cells are bricks surrounded and held together by membrane sheaths made of a ‘mortar’ of three lipids – cholesterol, ceramides and fatty acids, said the study by Elias and his colleague, Mao-Qiang Man, MD, a research scientist with the San Francisco Veterans Administration (VA) Health Care System-affiliated Northern California Institute for Research and Education.

“What’s important is that those three lipids are present at approximately equal ratios, equal numbers of molecules of each of them. When that ratio gets thrown off, he says, the membrane sheaths don’t completely fill the spaces between the cells. Then, instead of a brick wall, you get this Swiss cheese, which is not what you want,” said Elias.

Key observations from the research

The researchers observed that most common moisturizers are designed to provide a layer that prevents skin from getting too dry, which is fine for normal skin. However, these lotions may lack ‘mortar’ ingredients, contain them in the wrong proportions or change the skin’s naturally acidic pH.

Interestingly, the findings also revealed that the enzymes responsible for producing ingredients for the mortar work best at this acidic pH. This means the three lipids won’t be produced in the right ratios when the pH is thrown off. This can lead to a naturally occurring ‘Swiss cheese’ that triggers various skin conditions, including eczema.

“The body perceives the ‘Swiss cheese’ as an injury, and in response produces cytokines, small molecules that trigger the inflammation response that leads to healing. But in people with sensitive skin or skin conditions, their repair machinery – the enzymes that make the three lipids – aren’t functioning properly. So the injury remains and the cytokines keep coming, causing greater inflammation and irritation,” Elias explained.

The research also found that the majority of moisturizers haven’t been tested on people with sensitive skin. The problem is that using a moisturizer that doesn’t have the correct ratio of lipids or throws off the pH can simply exacerbate the situation and increase inflammation.

“It induces a vicious cycle where the patient is applying material frequently for temporary relief but the result is a long-term worsening of the skin,” he added.

The study concluded that for people with sensitive skin, the key lies in a lotion that is formulated for skin repair while also containing the ‘mortar ingredients’ in their correct proportions. Meanwhile, Elias and Mao-Qiang plan to carry out two large-scale studies in China.