What is the role of amino acids?To answer this, let’s backtrack a bit. We know that all living things, including ourselves, are made up of assemblies of cells. Despite the diversity of all living things, cells from all walks of life are remarkably similar in their chemistry and in their machinery to perform their basic functions. For example, all genetic instructions, or our genes, are stored in our DNA, written in the same chemical code, constructed using the same chemical building blocks, and duplicated in the same way during reproduction. These long DNA chains are made from the same set of four molecules, called nucleotides, connected together in different sequences. The instructions contained in your DNA are then read out into a related set of molecules known as RNA. The RNA, in turn, uses these messages to direct the synthesis of proteins, which can serve as molecular motors, chemical catalysts or even structural supports much like the protein collagen. These proteins are all made up of the same 20 different building blocks, and these building blocks are known as amino acids. They are linked together in different sequences in different proteins, supplying the protein with different chemical properties, just like how different sequences of letters can spell a different word with a different meaning. All that is kind of a long-winded way of saying that amino acids are just the building blocks of proteins, and there are only 20 different varieties of those blocks…depending upon what you read. It is quite possible you will be told or read that there are 21 amino acids, but we will get to that 21st entry in a future blog (it is very pertinent to the mineral selenium).
What are the most important amino acids for healthy hair, skin, and nails?
So now that we know what amino acids are, we can return to our original question. What are the most important amino acids for healthy hair, skin and nails? Well, one protein that we know is important, especially for our hair and nails, is keratin. Keratin helps maintain our hair and nail strength, and this is due in large part to strong bonds provided by sulfur atoms found in only two amino acids – methionine and cysteine. These two amino acids not only contribute to hair growth and strength, but also have strong antioxidant properties, which can help our skin in its battle against the damaging effects of UV-induced reactive oxide species, the effects of which can lead to premature aging. Our body cannot produce these two amino acids by itself, so they must be acquired through diet or supplementation. Excellent sources for cysteine include meats, lentils, eggs, yogurt, sunflower seeds and cheese. To ensure you are getting sufficient methionine in your diet, look again to meats and eggs, as well as milk, Brazil nuts, white beans, sesame seeds and quinoa. Given these best sources, if you are a vegetarian or vegan, you may wish to consider supplementation.
Another important amino acid for hair growth is lysine, which can not only help the body absorb calcium for bone health, but is also an important building block for collagen. We know that as we age, our body begins to slow down in its production of collagen, leading to a loss of skin elasticity and more wrinkles, so any boost we can provide in collagen production would benefit the appearance of our skin. Furthermore, deficiencies in lysine have been linked to hair loss and reduced hair volume, yielding another reason to ensure our lysine intake is at the appropriate level, because, just like methionine and cysteine, our body cannot produce lysine by itself. Instead, we need to acquire it through sources such as eggs, meats, fish, crab, cheese and green peas. Again, not particularly good news for vegetarians and especially vegans.
Proline would also rank highly as an important amino acid for your hair, skin and nails, as it constitutes ~33% of all the amino acids that are used to build collagen. Not only that, proline remains in very high demand by other proteins in our body, and plays an important role in our body’s ability to produce glycine, another important amino acid that we will discuss shortly. Dairy products, fish, meat, and gelatine are all excellent sources of proline, which again is not an ideal situation for vegans or vegetarians. If you subscribe to one of the dietary types, you may wish to consider supplementation.
And now, back to glycine. This amino acid is very important for the production of hemoglobin, the protein responsible for carrying oxygen through the bloodstream to all parts of your body, required for healthy cellular function. Glycine also has a second important role, as a key component in the production of one of the body’s most powerful antioxidants – glutathione. Excellent dietary sources of glycine are meat, fish, dairy products and legumes, but dietary sources will only provide about 20% of the daily requirement, so supplementation should definitely be considered.
Arginine is another important amino acid for hair, skin, and nails. It helps produce nitric oxide (NO), which has a relaxant effect on our blood vessels, allowing blood and the oxygen and nutrients it carries to be transported to the far reaches of our body where they can positively affect cellular function for hair and nail growth. Though our body can produce arginine, you will need to supplement this through diet. Meat, fish, seeds and nuts, legumes, and dairy products are all excellent sources.
A final amino acid to discuss is tyrosine, which helps produce melanin, the pigment that dictates the color of our hair and skin. More tyrosine in the skin will effectively lead to an increase in melanin levels, enabling the body to produce a natural tan more quickly and, more importantly, help prevent sunburn and other UV-related skin damage. There may be other claims for helping hair growth, but these seem to be more controversial and presently lack strong evidence. Our body can produce tyrosine by itself, so it is an example of a non-essential amino acid. Nonetheless, it can be found in meats, nuts, fish, and sesame seeds.