Oily hair and hair loss: is there a connection?

Oilyhairis due to an excess of sebum, referred to as hyperseborrhea, which can be caused by hormonal imbalance, stress, pollution or poor diet.

The primary cause of this scalp imbalance is an increase in the production of androgen hormones. In men, the main androgen hormone is testosterone, while in women, it is Δ-4-androstenedione and dehydroepiandrosterone. Within the sebaceous cells, these androgen hormones are converted into testosterone by various enzymes. Subsequently, this testosterone is transformed into dihydrotestosterone due to the action of an enzyme called 5-α-reductase, which stimulates the activity of the sebaceous glands. Individuals with highly active 5-α-reductase are therefore more likely to be prone to overproduction of sebum.

External factors can also be implicated, notably pollution, UV rays or unsuitable hair products that can harm the scalp and lead to an over-stimulation of the sebaceous glands and the production of an excess of sebum to protect the scalp. Finally, the frequent consumption of high glycemic index foods results in a spike of insulin in the blood, which also triggers an increase in androgen levels, and thus indirectly causes an excessive secretion of sebum.

Oily hair is due to an excess of sebum (hyperseborrhea) which can be caused by hormonal imbalance, stress, pollution or poor diet. Combined with sweat, sebum forms the hydrolipidic film that covers the entire surface of the skin. It helps to protect the horny layer from dehydration by maintaining hygroscopic substances within the epidermal cells. Its role is to prevent hair from becoming dry and brittle.

Excess sebum gathers and accumulates in the follicular ducts thereby blocking the proper oxygenation of the hair, as well as its normal growth and development. Due to hyperseborrhea, the hair becomes thinner, shorter, duller, and more fragile with each growth cycle. Indeed, this excessive production of sebum can lead to a progressively shorter anagen phase until the follicles die and the hair subsequently falls out.

Several studies have also noted that hyperseborrhea can exacerbate cases of female baldness: FPHL (Female Pattern Hair Loss). Indeed, hyperseborrhea is associated with an increase in the production of androgen hormones. These lead to an acceleration of the hair cycle and the renewal capacity of hair follicles will prematurely deplete, inducing hair loss. This refers to hair loss that occurs in women suffering from androgenetic alopecia. Thus, generally, while excess sebum does not cause hair to fall out, it can nevertheless disrupt its growth and ultimately generate alopecia or exacerbate it if it is already present.

However, it is possible to prevent scalp hyperseborrhea with simple measures. We first suggest maintaining a regular hair care routine with gentle products that do not irritate the scalp. It is advisable to avoid washing your hair too frequently or using an excessive amount of shampoo, as this can damage the scalp's hydrolipidic film and stimulate sebum production. It is recommended to limit washing to a frequency of one shampoo every two days and to alternate between a regular shampoo and a purifying treatment. Indeed, this type of treatment allows the scalp to be cleaned, sanitised, and purified. Clay is also a recommended active ingredient for oily hair as it helps to absorb excess sebum. For this, you can apply a clay hair mask once a week.

Thus, through these actions, it is possible to regulate sebum production and limit hair loss associated with hyperseborrhea.

• PIÉRARD G. E. & al. Women’s skin throughout lifetime. BioMed Research International (2014).