Hair loss is a “top” problem for many people. Previous scientific studies have shown that genetics, immunity, stress, late nights, medications (e.g. chemotherapy for hair loss) can cause hair loss. A new study shows that the ubiquitous microplastics can also cause hair loss.
Recently, Chu Weiwei, an associate researcher at the First Affiliated Hospital of Bengbu Medical University, and Wang Xusheng, a professor at Sun Yat-sen University, collaborated on a team to elucidate a new mechanism of hair loss - aging polystyrene microplastics pass through the esophagus and stomach, enter the blood circulation of mice, and then are deposited in hair follicle tissues, which increases the level of oxidative stress and destroys the tight junctions between hair follicle cells and each other. This increased the level of oxidative stress and disrupted the tight connections between hair follicle cells, resulting in hair loss. The findings have been published in the journal Environment International.
“This study reveals a new causative factor leading to hair loss problems and provides a target for intervention and treatment of microplastic pollution-induced hair loss.” Chu Weiwei told China Science Daily.
In recent decades, global plastics production has grown substantially and continuously. The continuous development of the plastics industry has also brought about the problem of “microplastic” pollution, which poses a major threat to human and animal health, and has now attracted worldwide attention.
Polystyrene is a common plastic term, refers to the structure of the benzene ring and vinyl polymers composed of common, lightweight, transparent, high strength, more used in food packaging.
Chu Weiwei said, “polystyrene products decomposed into microplastics, a large number of enriched in the natural waters, and then through the ultraviolet radiation in the sunlight, the microplastics undergo aging, and it is very easy to be directly absorbed by humans and animals through the drinking water and food chain cycle.
In fact, many researchers have identified and proven the effects of microplastics on the human body, including tissues and organs such as the brain, heart and blood vessels.
Hair loss, which is a problem for many people, and is trending younger and more prevalent. However, the mechanism of hair loss is currently far from being sufficiently revealed.
Chu Weiwei et al. asked whether there is some correlation between water quality, young people's lifestyle habits and hair loss? Therefore, they gathered to the water and takeaway plastics, guessing that the intake of microplastics may be a trigger for hair loss.In the lab, Chu Weiwei and others first simulated the aging process of polystyrene microplastics.
“Through electron microscope scanning and spectroscopic measurements, it was confirmed that UV radiation causes the aging of polystyrene microplastics, changing their surface roughness and increasing the content of oxidized groups.” Chu Weiwei said.
Further, they conducted mouse experiments. It was found that feeding the mice either virgin polystyrene or aged polystyrene (30 mg/kg body weight per day) caused skin and hair follicle damage and diffuse hair loss after 2 months.
“This is mainly due to the ingestion of polystyrene microplastics rich in oxidized groups, which are deposited at the hair follicle, causing high levels of oxidative stress levels, disrupting the tight junctions between hair follicle cells, leading to loosening of the epidermal structure at the hair follicle, causing hair loss and delaying the entry of the hair into the anagen phase.” Chu Weiwei made an analogy, if the normal skin is regarded as a piece of moist and nutritious land, and the hair is regarded as a plant, the presence of polystyrene microplastics will lead to the land drought cracking and losing its adhesion, and the plant will not be able to take root and survive.
“Of particular note, aged polystyrene microplastics can induce higher levels of oxidative stress within the hair follicle, exacerbating the damaged tight junctions because they contain more oxidized groups. In other words, the longer polystyrene microplastics exist in nature, the more pronounced is the role in causing hair loss.” Chu Weiwei said.
Systematic study of other triggers of hair loss
The reviewer of Environment International commented on the results, “The study innovatively reveals the occurrence mechanism of microplastics causing skin toxicity and leading to the role of hair loss, and provides new insights into the risk assessment of microplastics.”
Chu Weiwei emphasized that normal water quality, microplastic concentration will not reach such a high concentration in the experiment, but beware of the enrichment effect of aquatic animals, try not to eat raw wild aquatic products, especially their internal organs. At the same time, avoid heating food with plastic products to reduce the intake of microplastics.
“The next step, for the daily may cause the occurrence of hair loss of a variety of triggers, systematic scientific research, clear whether these behaviors, supplies will cause hair loss, and provide relevant therapeutic targets, the development of a new and effective, with the country's own property rights of hair loss prevention and treatment drugs.” Chu Weiwei said.
Related paper information: https://doi.org/10.1016/j.envint.2024.108638
