Will this ingredient help reverse hair greying?
Citrus Reticulata (Tangerine) Extract (and) Acetyl Tyrosine (and) Pentyleneglycol (and) D-Glucono-1,5-Lactone (and) Sodium benzoate (and) Water.
In this list, the “actives” are tangerine extract and acetyl tyrosine. The rest are solvents and preservatives. It’s not clear what is the extraction medium of the tangerine, but it could be simply juice.
Please remember that some citric fruits, including Tangerine, may contain some phototoxic chemicals, like furocoumarins, in their essential oils. See my post on the subject here.
Figure: Tangerine
How would this work?
The enzyme tyrosinase uses the amino acid tyrosine to make a precursor to melanin. Tyrosine will only help with grey hair if the problem is that your body does not have enough tyrosine, i.e. that tyrosine is the limiting factor in the synthesis of melanin. Humans can make tyrosine but they need another amino acid, phenylalanine, to do that. If you eat enough protein, you should have enough tyrosine.
Is lack of tyrosine the reason why our hair goes grey? Not really, the problem, as I have discussed before, is the decrease in activity of the enzymes that are involved in defending us from oxidants: methionine sulfoxide reductase (MSR) and catalase. Of course we want tyrosine, and we have it (together with other amino acids) in our hair serum. Also, there is no reason whatsoever why tangerine could help. Unless, of course, it is a powerful source of MSR and catalase (see below) which it isn’t.
From my book:
The science of gray hair
Following the discovery that follicles lacking in two crucial antioxidant enzymes make gray-white hair, we added these two enzymes to our Hair Care Serum that should help protect your scalp and prevent the loss of hair color.
Gray hair happens because there is little or no melanin incorporated in the hair as it is being formed in the follicle. It has been known for some time that oxidants were implicated in the damage and death of the melanocytes in the follicle, and new evidence shows that hydrogen peroxide (H2O2) accumulates in the hair shafts of gray-white hair. Two enzymes are involved in the prevention and repair of oxidative damage: catalase and methionine sulfoxide reductase. In gray hairs, these two enzymes are almost entirely gone.
Catalase breaks down hydrogen peroxide, preventing damage to the cell’s DNA and membrane lipids. On the other hand, methionine sulfoxide reductase (MSR) repairs protein damage. For example, MSR can fix a damaged (oxidized) amino acid in tyrosinase, the key enzyme of melanogenesis. Another way of preventing damage of tyrosinase by hydrogen peroxide is to have L-methionine in the environment.
In short, this new tangerine extract is a good addition to all the rubbish that people have been putting on their scalps in order to regain their original hair color. If you want to try it, make some tangerine juice and apply it to your scalp. Be aware that I have found no scientific papers on the effect of tangerine on human hair, so you will be your own Guinea pig!
Hannah