Proteins are large nitrogenous organic compounds that are essential components of all living cells. They form an essential component in the diet of all animals, including humans, and are necessary for the growth and repair of tissues. Proteins also serve as hormonal messengers and enzyme catalysts.
All proteins are made of polymers of amino acids. Amino acids are the molecular building blocks of proteins, and all proteins are different compositions of twenty basic amino acids. In chemistry, an amino acid is a molecule that contains an amine and carboxyl functional group.
Proteins are hydrolyzed into peptides and amino acids by enzymes in the digestive system. The blood stream carries peptides and amino acids to the various tissues in the body. Within the body, there is a continuous process of breaking up and re-synthesis of tissue proteins as the amino acids get incorporated or eliminated from them.
While some amino acids can be synthesized from other compounds by the body, others must be acquired externally through a proper diet. These amino acids help in proper growth and sustenance of the body. These eight essential amino acids are crucial for physical as well as brain health. However, the situation can not be generalized so easily. Four amino acids cysteine, tyrosine, histidine and arginine that can be synthesized by the body are considered semi-essential, because the pathways required for their synthesis are not fully developed in children, and therefore must be part of a child’s diet.
Methionine is an essential amino acid that helps in lowering histamine levels in blood.
Higher levels of histamine can cause the brain to convey wrong signals. It is also one of the causes behind schizophrenia. Besides this direct
brain function, methionine is
an effective anti-stress factor. Methionine deficiency
can cause cholesterol deposits and has been associated with atherosclerosis. As the blood vessels thicken, the supply of necessary oxygen-laden
blood to the brain can be hampered.
Phenylalanine is an electrically neutral but essential amino acid coded by DNA. It aids in the transmission of nerve signals between nerve cells in the brain. It is converted into other DNA-coded amino acids, tyrosine and dopamine, neurotransmitters essential for brain health. It can also be converted into norepinephrine, a precursor of epinephrine, secreted by the adrenal medulla to counter mental stress.
Phenylalanine crosses the blood-brain barrier as tryptophan, another essential amino acid. Tryptophan is used by the brain in conjunction with vitamin B6, niacin and magnesium to produce serotonin, which plays an important role in brain functions like depression, memory, and mental focus.
Tyrosine is another essential amino acid which is a precursor of many hormones, and is involved in stimulation and modification of brain activity. It is only after phenylalanine is converted into tyrosine that it becomes effective as a mood elevator and appetite suppressant.
Essential amino acids feed the brain’s neurotransmitters that are involved in behavior and learning skills. Various amino acids are a part of the continuous process where they undergo conversion, incorporation and elimination to support and correct transmission of nerve impulses. In many cases, supplemental herbs and vitamins that promote mental focus act in tandem with amino acids for the brain to transmit appropriate signals. As proteins are the main source of essential amino acids, it is imperative that you eat sufficient quantities of meat, fish, poultry, eggs, cheese, milk, yogurt, or soy, which are the most easily available sources of high quality proteins.