The Essential Amino Acids (Part 2): Methionine, Phenylalanine, Theronine, Tryptophan and Valine

Methionine helps with metabolism and breaks down fat, thus preventing a build-up of fat in the arteries. It also helps the digestive system, being converted into cysteine a predecessor to gluthione which is very important in detoxifying the liver. It is also one of the three amino acids which manufactures creatine monohydrate- essential for energy production and muscle building. Methionine, choline and inositol belong to a group of compounds called lipotropics- they help the liver process fat. Once in the liver, methionine is converted into s-adenosyl methionine. The World Health Organization states that the appropriate amount of methionine is 10.4 mg per kilogram of body weight daily. Foods high in methionine are: cod, cottage cheese, Brazil nuts and eggs.

Phenylalanine comes in three forms: L-phenylalanine- found in proteins, D-phenylalanine- manufactured in a lab and DL-phenylalanine- a combination of the two. Phenylalanine is converted into tyrosine, a non-essential amino acid that affects mood. Tyrosine also elevates catecholamines in the CNS and plasma; there are links between catecholamine’s and happiness hence why performance can be enhanced with tyrosine and phenylalanine because of the reduced mental stress. Why do bodybuilders use it? To keep them in the zone- put simply. Foods high in phenylalanine include: egg whites, cotton seeds, milk, beef and pork.

Similar to methionine, threonine helps the liver with lipotropic function- the digestion of fats and fatty acids, they work together to achieve this. It also helps keep connective tissues and muscles throughout the body strong and elastic, particularly the heart where it is found in abundance. Foods rich in methionine are: beans, poultry, lentils and raw eggs.

Mood regulation and sleep are regulated by the chemical serotonin, this and melatonin are both products of tryptophan. When carbohydrates are consumed alongside this amino acid, it drives the other amino acids into the skeletal muscles. Interestingly, turkey is one food extremely high in tryptophan, melatonin (a product of the amino acid) prompts drowsiness and the onset of sleep. This may be why on Christmas day you feel tired after consuming turkey! Foods high in tryptophan include: cod, shrimp, lamb, salmon, turkey, tuna and chicken.

Valine is necessary for the smooth nervous system and cognitive functioning, alongside leucine and isoleucine it makes up the three BCAA’s. Derived from animal and vegetable protein, valine is used for muscle metabolism and helps speed up recovery time after exercise. It helps to maintain the correct amount of nitrogen in the body and preserve muscle tissues. Little scientific evidence supports the claims that valine actually promotes muscle growth, research has shown it does however restore muscle mass in people with liver disease, injury or have undergone surgery. Leafy vegetables, kidneys beans, poultry and milk are just some foods high in valine. An interesting point about valine, it is not processed by the liver; it is taken up by the muscles.