Black seed oil, a natural remedy against white hair?

The emergence of white hair, commonly referred to as canities, is a phenomenon often associated with a decrease in melanin production by melanocytes and a gradual reduction in their number. Depending on the individual, this natural process usually occurs around the age of 35. However, ageing is not the only factor contributing to the appearance of white hair. Genetics also play a major role, as does prolonged stress or nutritional deficiencies.

Furthermore, the whitening of hair is accelerated by stress oxidative caused by prolonged exposure to UV rays or pollution. Indeed, at the scalp level, ROS (reactive oxygen species), free radicals, attack the stem cells of melanocytes and induce them into apoptosis. As a reminder, apoptosis is the process by which cells trigger their self-destruction. This reduces the population of follicles in the anagen phase, that is, the growth phase, by melanocytes, and therefore leads to a depigmentation of hair. Moreover, over time, the activities of the anti-apoptotic protein BCL-2 and the antioxidant enzyme catalase decrease, which facilitates the attack of melanocytes by free radicals and their apoptosis.

Theblack seed oil is a vegetable oil extracted following the cold pressing of black cumin seeds. Rich in saturated and unsaturated fatty acids, as well as active principles, it bestows a multitude of benefits to the skin and hair. Its composition notably gives the black seed oil its antioxidant, moisturising and anti-inflammatory properties.

The topical application of black seed oil can, to some extent, help to delay the onset of greying hair. However, it cannot act on already formed white hair. To slow down the greying process, black seed oil utilises thymoquinone, its active ingredient. This molecule works by protecting hair fibres and the scalp from oxidative stress caused by free radicals by upregulating the activity of certain antioxidant enzymes, such as superoxide dismutase (SOD), glutathione peroxidase (GPx), and also catalase. Thus, black seed oil is capable of protecting the melanocytes, and preserving their melanin synthesis activity, which is essential for hair colouration.

Note : While the correlation between oxidative stress and hair greying has been scientifically established, no study focusing on black seed oil has investigated its effects on greying hair. Therefore, although the antioxidant properties of this ingredient seem promising in combating the onset of white hair, caution is advised.

• SEIBERG M. Age-induced hair greying - the multiple effects of oxidative stress. International journal of cosmetic science (2013).

• KIM B. & al. Black Cumin ( Nigella sativa L.): A Comprehensive Review on Phytochemistry, Health Benefits, Molecular Pharmacology, and Safety. Nutrients (2021).