Skin under influence

The effects of climate change on skin health are largely unknown. Scientists at the IUF – Leibniz Research Institute for Environmental Medicine in Düsseldorf conducted an epidemiological study to investigate the relationship between temperature and humidity and the aging of human skin. The initial results have now been published in the journal Dermatitis. The work was carried out in collaboration with scientists from the Environmental Science and Engineering Department of the Indian Institute of Technology Bombay (IIT) in Mumbai, India, and the cohort studies in India were financially supported by Amway, Ada, Michigan, USA.

Global warming and extreme heat events are having an increasing impact on human health. In corresponding studies, the ambient temperature and relative humidity are summarized as the heat index, as they influence and reinforce each other. As the heat index increases, so does the risk of various diseases such as cardiovascular and lung diseases. Although the skin is the organ in direct contact with the environment, it is currently unknown whether skin health is also affected. Mechanistic studies have provided evidence of biological processes that are affected by heat and may contribute to skin aging. The paper now published in Dermatitis is the first epidemiologic study to examine the relationship between heat index and skin aging. India, with its different climate zones and higher temperatures compared to our latitudes, is particularly suitable for these studies.

For the study, signs of skin aging such as pigmentation spots and wrinkles were assessed in 1,510 Indian women from three different cities using a scoring system (SCINEXA). In addition, data on ambient temperature and relative humidity, which were combined into a heat index, as well as data on ultraviolet radiation and air pollution (particulate matter<2.5µm; nitrogen dioxide) were collected for the last 5 years in the respective residential areas. An adapted ordinal multivariate logistic regression model was used to calculate the statistical relationship (so-called association) between heat index and signs of skin aging. This showed that the pigmentation on the forehead and coarse wrinkles such as crow’s feet and wrinkles under the eyes also increased significantly with increasing heat index. These associations were independent of the age of the participants and other environmental factors such as solar UV radiation, smoking status and air pollution.

“This is the first epidemiological study to show that climate change can increase the aging of human skin,” comments Prof. Jean Krutmann, Director of the IUF, on this study, which he led. “In current investigations, we are analyzing the mechanisms responsible for this with the aim of developing protective strategies for the skin.” “We also want to investigate whether and how heat and air pollution interact in skin aging,” adds Prof. Tamara Schikowski, environmental epidemiologist at the IUF.

Publication

Singh N, Wigmann C, Vijay P, Phuleria HC, Kress S, Majmudar G, Kong R, Krutmann J*, Schikowski T: Combined effect of ambient temperature and relative humidity on skin aging phenotypes in the era of climate change: Results from an Indian cohort study. Dermatitis 2024. (* corresponding author). https://www.doi.org/10.1089/derm.2024.0301

Further information and contact

Presse release - IUF – Leibniz Research Institute for Environmental Medicine