"Amino acids work as building blocks, protectors of the cells, alleviators of pain, generators of ecstasy, and guardians of health. All the body's tissue, every cell, muscle, hair, nail, enzyme, and brain chemical, is made from amino acids. They are central to the biochemistry of your body." (see Erdmann) "Amino acids can best be described as the construction blocks from which protein is made. The essential amino acids are critically important to life and health, for out of them the body makes the other amino acids, as well as many of the vital compounds which keep the body working, such as enzymes, neurotransmitters, mucopolysaccharides, etc., not to mention blood, muscles, organs and bones from which we are constructed." (see Chaitow) Each amino acid comes in two forms, a left-handed (L) and a right-handed (D) form. These two forms are identical in every way, except they are mirror images of each other, like our right and left hands. Our bodies are made mostly of L forms. The essential amino acids required for an adult body, in order to make the other amino acids as well as the proteins are: L-tryptophan, L-isoleucine, L-lysine, L-threonine, L-leucine, L-methionine, L-phenylalanine and L-valine.

     (A neurotransmitter is a substance such as dopamine, epinephrine and norepinephrine that is released when the axon terminal of a presynaptic neuron is excited. The substance then travels across the synapse to act on the target cell to either inhibit or excite it. These neurotransmitters are the brain's message carriers made by the brain from nutrient substances. Our brain cells communicate with each other via these special chemicals. (see Taber's and Wingard)

     Catecholamines are biologically active amines (dopamine, epinephrine and norepinephrine) derived from the amino acid L-tyrosine. They have a marked effect on the nervous and cardiovascular systems, metabolic rate, temperature, and smooth muscle. Catecholamine synthesis begins with the amino-acid phenylalanine. The essential amino acid phenylalanine is used for two major purposes: tissue protein synthesis and hydroxylation to form L-Tyrosine. It also metabolizes to phenylethanolamine, phenylacetic acid, and phenylpyruvic acid. However, L-Tyrosine is the normal immediate product of phenylalanine which is itself essential to five other metabolic pathways. These include the synthesis of tissue protein, epinephrine, melanin pigment, thyroxine and energy production through parahydroxy phenylpyruvate to fumarate and acetoacetate. (see Shils)

Catecholamine metabolism:
     PHENYLALANINE---> phenylalanine-hydroxylase(enzyme activity)---> TYROSINE---> tyrosine hydroxylase(enzyme activity)---> dihydroxyphenylalanine (L-DOPA)---> aromatic-L-amino acid decarboxylase (enzyme activity)---> DOPAMINE---> dopamine beta-hydroxylase (enzyme activity) --->NOREPINEPHRINE---> phenylethanolanine-N-methyl transferase (enzyme activity)---> EPINEPHRINE. Vitamins C, B-3 and B-6 are required co-factors. (see Erdmann, Pearson-Shaw, Shils)

     Catecholamines are responsible for a number of different effects in normal humans. They are involved in the control of locomotor (moving about) behavior, aggressive behavior, sexual behavior, food intake, and behavior dependent upon positive or negative reinforcement (reward-punishment). Dopamine affects sex drive, locomotion, tissue growth and repair, the immune system, and moods. Dopamine increases blood pressure, especially systolic (top number) and it increases urinary output. Norepinephrine affects primitive drives and emotions like sex , memory and learning. NE is chiefly a vasoconstrictor (a binder, a narrowing of blood vessels). Low levels of NE can lead to depression. (see Pearson-Shaw) Both dopamine and NE can be converted back and forth, one to the other in the brain. (see Pearson-Shaw) NE controls the classic 'flight or fight' state in which blood is diverted to the muscles and away from the thinking brain to the primitive emotional 'reptile' brain. (see Wingard)

     Phenylalanine triggers the release of cholycystokinin (CCK). Low levels of CCK signal the brain that food is needed. In normal humans CCK levels rise within 30 minutes to a new higher level which tells the brain that you have eaten enough and are 'full'. Phenylalanine is also converted into noradrenaline (Epinephrine) which elevates mood and reduces the desire to eat. Phenylalanine as the pre-cursor to L-Tyrosine also helps your body to stay at its desired weight once you reach it. (see Erdmann 73-75) Phenylalanine through epinephrine production, causes an increase in cyclic adenosine monophosphate (cAMP) which increases lipolysis (breakdown of fat) coinciding with an inhibition of glycogen synthesis (potential fat storage). (see Wingard 544)

     According to Pearson and Shaw the dose of L-phenylalanine required for appetite suppression will vary from person to person. They suggest starting with a small dose (100 mg.) and slowly working up to an effective dose. Be sure to get the assistance of your physician in titrating doses. If you take too much, you can get symptoms such as insomnia, irritability, or that 'wired' feeling. (see Pearson-Shaw Weight Loss Program 333-334)(Chaitow pg. 52-56) A high protein diet can supply about 4 grams of L-phenylalanine per day.

     We have now seen that phenylalanine, an essential nutrient amino acid, can inhibit appetite by increasing the brain's production of catecholamines and CCK. Amphetamines (and amphetamine-like drugs, ie. phentermine) work by causing the brain to release NE from its stores and by blocking its re-uptake and re-use. (see Pearson-Shaw Life Extension 287) Phenylalanine causes the brain to increase both production and storage of NE, rather than depleting it as phentermine does. Tolerance to anorectic drugs occur because the brain is depleted of noradrenaline by tose drugs. (IBID) Anorectic drugs (amphetamine, phentermine, ephedrine, phenmetrazine, diethylpropion, mazindol) work by reducing energy intake (food) and increasing energy output (heat and work, ie. thermogenesis). These drugs should only be used under a doctor's care. The goal being a loss of fat rather than loss of lean body mass. Without vigorous exercise along with growth hormone releasers, and adequate protein intake, about 25 per cent of the weight lost will be LBM. (see P-S WLP pg. 14-72)

     The use of amino acids starting several days AFTER discontinuing the anorectic drug has much less hazard potential for most people and may be able to prevent post drug 'rebound' eating by replenishing the depleted noradrenaline stores. (IBID) Check with your physician about 'pulsing' (see Lamm pg. 198) amino acids with your drug therapy. Taking the drugs and the amino acids simultaneously may lead to excessive and dangerous increases in blood pressure and cardiac arrhythmias. Do not self-medicate.

     Serotonin (5-HT) has a significant affect on our moods. It is associated with obsessive-compulsive disorders. Low levels of serotonin can cause a person to crave food all the time. (see Lamm) Serotonin is an inhibitory neurotransmitter which calms the brain down and relieves anxiety and tension. It is the direct pre-cursor to melatonin the 'sleep' hormone. The amino acid tryptophan is the essential amino acid precursor to serotonin. The metabolic pathway of tryptophan looks like this. L-tryptophan---> tryptophan hydroxylase (enzyme activity)---> 5-hydroxytrptophan (5-HTP)---> aromatic L-amino acid decarboxylase(enzyme activity)--->5-Hydroxytryptamine (5-HT, serotonin)---> N-acetyl-serotonin--->Melatonin--->5-Methoxy-Tryptamine.

     Dietary protein and carbohydrate content can specifically influence brain tryptophan and serotonin levels by effects on plasma amino acid patterns. The natural isomer L-tryptophan may cause side effects of sleepiness, headache, sinus congestion or constipation, or intestinal cramping due to contraction of smooth muscle. Some individuals will be stimulated by tryptophan instead of being sedated. Vitamins C, B5, B6 and B3 are co-factors. (see Cooper, et. al. pg. 354, Erdmann pg. 18-33, P-S LE pg. 179) One of the effects of a high protein meal is that less tryptophan is able to reach your brain. Carbohydrates actually help you raise your brain's tryptophan levels in relation to other aminos. That is why some high-protein dieters crave carbohydrates and the impulse becomes an overwhelming carbohydrate binge, if carbohydrates are not eaten to maintain serotonin. (see Erdmann pg. 77)

     The phenomenon of carbohydrate craving is most likely the result of reduced serotonin. Higher concentrations of serotonin lead to a choice of less carbohydrates and more protein in subsequent meals. Therefore, if tryptophan rich food is ingested before a meal with controlled amounts of carbohydrates, the serotonin levels will rise and carbohydrate cravings should be expected to cease. (Chaitow pg. 57-66) The symptoms of anxiety, tension or depression, mentioned by many people prior to a carbohydrate snack, and the relief felt afterwards, may be the direct result of serotonin lack followed by increased brain serotonin levels. Fenfluramine increases the release of serotonin and inhibits the re-uptake and re-use of that serotonin. Thus lessening cravings for carbohydrates. (see Lamm)

     "Carbohydrates set off a series of biochemical events that result in the brain making serotonin. This...stops the urge to binge", on sweet or starchy foods. (ie. candy, doughnuts, cake, cookies, cupcakes, frosting, cookie dough, chocolate chips, popcorn, bagels, potatoes, cereal, rice, pasta, etc.) Eating carbohydrates is the only [non-drug] way to boost serotonin levels in the brain." (Wurtman pg. 9) Why? Because tryptophan as a molecule is large compared with other amino acids. The huge cumbersome tryptophan molecule must compete with 7 smaller aminos for absorption through the intestinal wall. It must then compete with these smaller aminos for the limited number of 'carriers' to penetrate the brain-blood barrier. However, carbohydrates facilitate tryptophan uptake in the brain by clearing the competing aminos out of the bloodstream with an insulin release.

     Whether one gets increased amounts of L-Tyrosine and L-tryptophan from food or supplements is a matter of personal choice and biochemistry. I follow a controlled carbohydrate eating plan. I add supplemental L-Tyrosine in the morning on an empty stomach, along with vitamin C and B-complex. I believe this routine effectively suppresses the appetite and leads to a feeling of being physically full by the release of cholycystokinin, while elevating moods and reducing the desire to eat. Plus increasing the metabolism through an increase in brown fat thermogenesis and an increase in natural thyroxine levels. In my opinion L-Tyrosine helps to prevent depletion of catecholamine storage in the brain.

     To weaken carbohydrate cravings, to help build muscle, and for an energy boost I use 5-15 grams of L-Glutamine daily along with vitamins C and B-complex as co-factors. For a serotonin boost I take 50 mg of 5-htp first thing in the morning and another 50 - 100 mg just before bedtime.

     A physician willing to work with you in balancing these drugs and nutrients is a MUST.