L-cystine and L-tyrosine

I’m pretty obsessed with the lean protein. Proteins are the building blocks for hair. It also happens that I’m a total carnivore by nature (Much to the annoyance of my wannabe-tarian hubby) and will be hungry and cranky again in no time if I’m not fed a proper protein-rich meal.

Unfortunately this is one of the times where I really wish I had taken chemistry on a higher level in college and the feeling of “I think I should understand this better” is truly irritating. I can’t guarantee that this blog post is 100% correct, but this is what I understand so far. Corrections and explanations are very welcome!

Anyways.

To start with the basics: Amino acids are the building blocks of proteins. Amino acids come in essential and non-essential. Essential means that the human body can’t produce it itself out of other building blocks and are essential to be supplied through diet.
As commonly known, human hair is constructed mainly from protein and there are two amino acids mentioned as the main ones: L-cystine and L-tyrosine.

Cystine is a non essential amino acid formed by two cysteine molecules joined together. This might explain why both “cystine” and “cysteine” are used seemingly at random: Cystine is basically double-cysteine (?) It is necessary for a lot of body functions, but I will focus on the hair. L-cystine takes up between 6 and 14% of the hair strand depending on the source. Cysteine is based on sulphur and found in a lot of common food groups such as poultry, eggs, dairy products, onions, oats and broccoli.

Tyrosine is non essential as well, but on a condition: It is synthesized in the body from Phenylalanine, which is an essential amino acid. So if the body isn’t supplied with Phenylalanine it will not be able to synthesize Tyrosine. The correct term for this is “conditionally essential”.
L-Tyrosine helps produce melanin, the pigment that gives hair and skin colour. Tyrosine is important for the thyroid function, but here it gets confusing and I have the nagging feeling I haven’t understood it correct: From what I gather, Tyrosine is necessary for the thyroid to produce stress-hormones. Stress hormones helps the body and mind deal with stress and keep the physical impact of stress down. Of course what I already know is that thyroid issues can cause different types of hair loss or other hair health issues. Tyrosine is found in a lot of common food groups such as poultry, dairy products, soy, avocado and nuts.

I take protein tablets, a medical-grade protein supplement at 2 gram per day (About 3 % of my daily protein requirement) It contains 60 mg tyrosine and 18 mg cystin. No serious source has any recommended daily allowance of these two amino acids (Well, of course if we ask a source that also sells these two in supplement form, we need to take so-and-so much of it for healthy hair and it also happens to be the amount found in their amazing tablets. How lucky!)

It’s probably completely silly of a carnivore like me to obsess over this, especially since both amino acids are actually hard to avoid in the diet! It’s even sillier to obsess over buying protein supplements after if these two non-essential amino acids are in it or not.