Tag Archives: brain

Anorexia Patients’ Serotonin Levels Helped by Amino Acid Tryptophan

Serotonin is the feel-good chemical that the human brain produces in the body. People with higher serotonin levels generally are more resistant to depression, anxiety, and other negative emotions. People with adequate levels of serotonin also feel better about life, themselves, and their place in the world. Anorexic patients, suffering from the eating disorder called Anorexia nervosa, have mental and emotional as well as physical issues surrounding this disorder, and consequently can have too-low serotonin levels. Raising serotonin can be done by natural means, such as taking the amino acid L-tryptophan. Tryptophan is a neurotransmitter in the brain, which can help raise serotonin levels.

 Tryptophan is used by the body and produces serotonin in the brain, which is severely lacking in those with anorexia. This eating disorder is associated with an obsession of being overweight, so they eat very little, and sometimes nothing at all, which leads to emaciation. Body image issues are at the forefront, self-worth is low, causing a spiraling effect since anorexics think they are too fat even if they are skin and bones. Very low food intake (and therefore low in tryptophan) depletes the serotonin in the brain, since it is tryptophan dependent.

Tryptophan is an amino acid that comes from protein foods, like meats (chicken, beef, pork, lamb, etc.), as well as fish and eggs. A diet deficient in meats is also deficient in not just tryptophan, but also the rest of the common 22 amino acids that make a body healthy and resistant to disease and other health issues.

Study using tryptophan for serotonin levels in anorexic patients

A study by DJ Haleem from the Neuroscience Research Laboratory at the University of Karachi in Pakistan was done regarding anorexia patients and tryptophan. Haleem said “Patients with anorexia nervosa (AN) show extreme dieting weight loss, hyperactivity, depression/anxiety, self-control, and behavioral impulsivity. Tryptophan, the precursor of serotonin and an essential amino acid, is only available in the diet. It is therefore likely that excessive diet restriction and malnutrition decrease brain serotonin stores.”

When serotonin is low, then the availability of tryptophan “decreases serotonin neurotransmission at postsynaptic sites, leading to hyperactivity, depression, and behavioral impulsivity,” said Haleem. He suggested that tryptophan “supplementation may improve pharmacotherapy in AN.”

The effectiveness of tryptophan on serotonin levels for anorexia has not yet been evaluated, but the fact that higher serotonin levels make us feel better is well documented. Tryptophan is an amino acid that is easily bought over the counter at health food stores for supplementing the diet.

References:

http://www.ncbi.nlm.nih.gov/pubmed/22854305

http://www.mayoclinic.com/health/anorexia/DS00606

Sulfur-Containing Amino Acids Cysteine and Methionine

The two main sulfur-containing amino acids are cysteine and methionine; however, there are other sulfur-containing amino acids as well. Both cysteine and methionine are nonpolar as well as hydrophobic, with methionine being extremely hydrophobic as far as amino acids go. Methionine is also found inside proteins, and cysteine is often found there too. There are some other fascinating things about these two (and other) sulfur-containing amino acids.

Aside from methionine and cysteine being most popularly known, other commonly known sulfur-containing amino acids include homocysteine and taurine. The last two are not incorporated into proteins, however. According to the authors at the Journal of Nutrition (JN), the “difference accounts for some of the distinctive properties of the sulfur-containing amino acids. Methionine is the initiating amino acid in the synthesis of virtually all eukaryotic proteins … [and if] exposed, are susceptible to oxidative damage. Cysteine, by virtue of its ability to form disulfide bonds, plays a crucial role in protein structure and in protein-folding pathways.”

The authors of JN discuss a number of these sulfur-containing amino acids—methionine, cysteine, taurine, homocysteine, and the lesser known S-adenosylmethionine.

Importance of sulfur-containing amino acids

Although cysteine and methionine are the primary sulfur-containing amino acids due to being two of the 22 common amino acids that are incorporated within proteins, both taurine and homocysteine are also important for physiological function. So why is sulfur in amino acids since most aminos are made of carbon, oxygen, hydrogen, and nitrogen? Because, says JN, oxygen and sulfur both belong to ‘Group 6’ of the Periodic Table of Elements, so are “capable of making similar covalent linkages” with a critical difference that sulfur has a low electronegativity (oxygen has the second lowest electronegativity). So if oxygen replaces the sulfur it would “result in a much less hydrophobic amino acid.”

Furthermore, substituting oxygen for sulfur—causing oxidation—in sulfur-containing amino acids (including in the more rare S-adenosylmethionine) can have effects in methionine residues where the surface is exposed, causing an oxidation-reduction cycle, imparing the activity of “methionine sulfoxide reductase and the subsequent accumulation of methionine sulfoxide residues [that] are associated with age-related diseases, neurodegeneration, and shorter lifespan.”

Lastly taurine, as one of the more remarkable sulfur-containing amino acids, has very high concentrations within muscle tissues and utilizes a wide variety of functions. Taurine is, says JN, the “most abundant free amino acid in animal tissues [even though it] accounts for only 3% of the free amino acid pool in plasma, it accounts for 25%, 50%, 53%, and 19%, respectively, of this pool in liver, kidney, muscle, and brain.” It is also one of the most necessary sulfur-containing amino acids for cats and results retinal degeneration in kittens if the mothers are not fed a taurine-rich diet. Taurine is also found in human mother’s milk and is added to many infant formulas because it helps with eyesight.

So all in all, sufur-containing amino acids are necessary for proper health of both animals and humans in the proper biological functioning and growth, as well being associated with some diseases and anti-aging and neurological issues.

Reference:

http://jn.nutrition.org/content/136/6/1636S.full