Bienfaits vitamine C cheveux.

Vitamin C: What are the benefits for hair?

As one of the most potent antioxidants for the skin, vitamin C is a crucial component of skincare routines due to its ability to create a more radiant and even complexion, and to protect against photoaging. But does it have as many benefits for the scalp and hair as it does for the skin? The effectiveness of vitamin C on hair health is garnering increasing attention. Let's explore this in this article.

Benefit #1: Vitamin C to slow down premature hair graying?

When vitamin C is applied to the scalp, it can have benefits similar to a topical application. However, one of the most widely accepted theories, initially proposed by HARMAN in 1956 and supported by experimental data, suggests that oxidative stress plays a major role in the hair aging process. As a result, ascorbic acid is a powerful antioxidant that could help protect the scalp and hair from oxidative damage caused by free radicals.

Indeed, it has been demonstrated that these reactive species, produced internally during normal metabolism and externally through exposure to various environmental stressors (cigarette smoke, UV rays, etc.), can affect the condition of hair fibers that emerge from the scalp, leading, for example, to premature graying of hair by prematurely inducing apoptosis in melanocyte stem cells.

However, by neutralizing and eliminating these harmful free radicals, the vitamin C could potentially limit these harmful reactions from occurring by possibly protecting the melanocytes and hair follicles from oxidative stress. It would then help to protect the hair from premature graying and maintain their shine. On the other hand, no research results explicitly mention the effect of applying vitamin C to the scalp to date.

Benefit #2: Vitamin C could enhance hair growth.

Several laboratory reports have demonstrated that vitamin C can influence hair growth. One study found that adding 0.25 mM of L-ascorbic acid 2-phosphate (magnesium salt), a stable derivative of vitamin C, to the culture medium resulted in increased proliferation of human dermal papilla cells. These cells, located at the base of hair follicles, are essential for hair formation and the regulation of the growth cycle. It has also been shown that L-ascorbic acid 2-phosphate promotes the elongation of hair shafts in human scalp hair follicles in culture.

In vivo data from mice has also shown that L-ascorbic acid 2-phosphate promotes hair growth by inducing an earlier conversion from the telogen (resting) phase to the anagen (growth) phase compared to the control group. It has been suggested that L-ascorbic acid 2-phosphate would induce the expression of growth factors, including IGF-1 by dermal papilla cells, which in turn increase the proliferation and differentiation of follicular keratinocytes to stimulate the growth of human hair follicles in vitro via the PI3K signaling pathway.

Although these research findings have not yet been subjected to clinical studies, they suggest that vitamin C could potentially influence hair growth.

Benefit #3: Vitamin C to prevent hair loss.

Androgenic alopecia is the most common cause of hair loss, induced by hormones (androgens). Research reveals that the dihydrotestosterone (DHT), produced from testosterone by the 5-α reductase enzyme, contributes to the miniaturization and shrinkage of the hair follicle. It has been shown that this hormone induces the expression of DKK-1 mRNA in dermal papilla cells. In fact, a high level of DKK-1 has been observed in the scalp of bald individuals, thus it would induce hair loss. However, in 2010, a study revealed that the addition of L-ascorbic 2-phosphate (0.25 and 1 mM) to the culture medium caused a downregulation of DKK-1 levels in response to DHT in dermal papilla cells, which means it may help prevent androgen-induced baldness.

Although promising, these initial data (in vitro) need to be replicated in actual patients.

Sources

  • KIM J. C. & al. The hair growth promoting effect of ascorbic acid 2-phosphate, a long-acting Vitamin C derivative. Journal of Dermatological Science (2006).

  • SUNG Y. K. & others. L-Ascorbic acid 2-phosphate stimulates the growth of hair shafts by promoting the secretion of insulin-like growth factor-1 from dermal papilla cells through the phosphatidylinositol 3-kinase pathway. British Journal of Dermatology (2009).

  • SUNG Y. K. & others. L-ascorbic acid 2-phosphate suppresses the expression of dihydrotestosterone-induced dickkopf-1 in human balding dermal papilla cells. Experimental Dermatology (2010).

Diagnostic

Understand your skin
and its complex needs.