Dr. Weeks’ Comment: we have known about the toxic effect of aspartame for almost 60 years. Not only is it a neurotoxin and not only does it spontaneously metabolize to toxic wood alcohol when heated (think of that diet soda sitting on the curb all day long in the hot summer) but it reduces the presence of healthy neurotransmitters also. Still the FDA endorses it.
The Influence of High Phenylalanine and Tyrosine on the Concentrations of Essential Amino Acids in Brain.
CM McKean DE Boggs and NA Peterson
The brain Behavior Research Ctr., Sonoma State Hospital Eldridge, CA 95431
(received 5 July 1967)
Abstract – High circulating levels of phenylalanine caused depletion of threonine, valine, methionine, isoleucine, leucine, tryptophan and tyrosine…
Aspartame cravings? Aspartame is a drug in your food.
The enzyme 4.1.1.28 (aromatic-L-amino acid decarboxylase) catalyzes dopamine synthesis (Figure 1), serotonin synthesis (Figure 2), histamine synthesis (Figure 3), and phenylalanine metabolism (Figure 4).
4.1.1.28 freely synthesizes dopamine from L-dopa and serotonin from 5-HTP without biochemical feedback inhibition.
The artificial sweetener aspartame (NutraSweet®, AminoSweet®) is metabolized to aspartame, methyl alcohol, and phenylalanine. Phenylalanine is the rate limiting step in the synthesis of phenylethylamine (Figure 4). Phenylalanine, through competitive inhibition of 4.1.1.28, decreases serotonin, dopamine, and histamine synthesis.
Increased levels of phenylethylamine (Figure 4) induces excretion of dopamine and norepinephrine. This leads to depletion of catecholamines through the same mechanism caused by reuptake inhibitors (see http://neurosciencemyths.com/Lexapro_side_effects.htm)
THE BOTTOM LINE
1. Aspartame is metabolized to phenylalanine.
2. Phenylalanine is metabolized to phenylethylamine inducing competitive inhibition of 4.1.1.28 leading to decreased synthesis of serotonin, dopamine, and histamine.
3. Increases in phenylethylamine leads to excretion and associated depletion of serotonin and dopamine (catecholamine depletion).
4. As always, with depletion of catecholamines epinephrine (adrenaline) synthesis is the first to suffer dysfunction and suffers the most. Epinephrine and histamine share an agonist-antagonist interaction. With both histamine and epinephrine synthesis being compromised the problems grow.
INSIDIOUS RESULTS
There are those caregivers that stick their head in the sand and refuse to acknowledge the chemistry with clinical impact and continue to give only 5-HTP or L-dopa without giving thought to obtaining proper balance of serotonin, dopamine, and the thiols (sulfur amino acid containing molecules). Sure giving only 5-HTP or L-dopa for a few weeks or months in most cases has no perceptible negative effects. But sooner or later it catches up with the patient. The 5-HTP or L-dopa quit working. 5-HTP depletes dopamine, and L-dopa depletes serotonin. When depletion of one system is great enough neither system will function.
The same is true with phenylalanine compromising serotonin, dopamine, and histamine synthesis. Things are OK today but repeated long term exposure is where the problems show up.
COULD THIS BE PART OF THE PROBLEM?
During the following time period aspartame ingestion by the general population increased by about 25%.Phenylalanine is 43% active on the tryptophan hydroxylase enzyme which in turn compromises synthesis of 5-HTP from tryptophan.
SIDE EFFECTS INDUCED BY CARBIDOPA INHIBITION
There is no need to use carbidopa with L-dopa in the treatment of Parkinson’s disease and other state if a proper balance between serotonin and dopamine is maintained.
Dyskinesias, choreiform movements, glossitis, leg pain, ataxia, falling, gait abnormalities, blepharospasm (which may be taken as an early sign of excess dosage), trismus, increased tremor, numbness, muscle twitching, peripheral neuropathy, myocardial infarction, flushing, oculogyric crises, diplopia, blurred vision, dilated pupils, urinary retention, urinary incontinence, dark urine,hoarseness, malaise, hot flashes, sense of stimulation, dyspepsia, constipation, palpitation, fatigue, upper respiratory infection, bruxism, hiccups, common cold, diarrhea, urinary tract infections, urinary frequency, flatulence, priapism, pharyngeal pain, abdmoninal pain, bizarre breathing patterns, burning sensation of tongue,back pain, shoulder pain, chest pain (noncardiac), muscle cramps, paresthesia, increased sweating, falling, syncope, orthostatic hypotension, asthenia (weakness), dysphagia, Horner’s syndrome, mydriasis, dry mouth, sialorrhea, neuroleptic malignant syndrome, phlebitis, agranulocytosis, hemolytic and nonhemolytic anemia, rash, gastrointestinal bleeding, duodenal ulcer, Henoch-Schonlein purpura, decreased hemoglobin and hematocrit, thrombocytopenia, leukopenia, angioedema, urticaria, pruritus, alopecia, dark sweat, abnormalities in alkaline phosphatase, abnormalities in SGOT (AST), SGPT (ALT), abnormal Coombs’ test, abnormal uric acid, hypokalemia, abnormalities in blood urea nitrogen (BUN), increased creatinine, increased serum LDH, and glycosuria.
A glycosuria.