German researchers of the Universities of Bochum and Muenster and English scientists of the Manchester University have published a few months ago a work on the prestigious journal Nature Communication (Cheret et al, Nat Commun, Sep 2018). In the article they state that hair may get benefits from the scent of sandalwood, how? By inhaling it… and here starts a very fascinating chapter about human body.
Our body indeed is covered by olfactory receptors, a part of the ancestral sensorial system then evolved in olfaction. These olfactory receptors aren’t limited to the nasal mucosa but are present in other human tissues, such as skin and, precisely, the hair follicles. The scientists have observed, in particular, that the topical applications of a synthetic product with a sandalwood smell is able to stimulate the olfactory receptors present in the hair follicles, called OR2AT4, and that this stimulation has the effect to protect the hair and its growth. Indeed, thanks to this application, the hair anagen phase is prolonged, this is the phase that corresponds to hair growth, while the premature apoptosis, namely the cellular death, of keratinocytes of the hair follicles, that precedes the hair fall, is inhibited. This premature cellular death happens on the contrary in androgenetic alopecia, the most common cause of hair loss in men and women, and telogen effluvium, that is a temporary increase of hair loss caused by, for example, intense stress or hormonal imbalance. A great result that paves the way to new treatments to counteract hair loss. However, we have to make a clarification. The study uses a synthetic product, that mimics the sandalwood scent and that has been created by a drug company that supported in part the research. This doesn’t invalidate the finding but it is also important to observe that sandalwood essential oil, not synthetic but natural, shows the same ability to counteract the hair loss by prolonging the anagen phase and delaying the hair fall, according to a scientific research performed in 2014 by Korean researchers (Lee BS, J Invest Cosmetol, 2014). Moreover, the same protective effect in the hair follicles can be achieved with lavender essential oil (Boo et al, Toxicol res, Apr 2016).