User:Richard T Murray/Aspartame: Difference between revisions

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http://groups.yahoo.com/group/aspartameNM/message/1143
http://groups.yahoo.com/group/aspartameNM/message/1143
methanol (formaldehyde, formic acid) disposition: Bouchard M et al, full plain text, 2001: substantial sources are degradation of fruit pectins, liquors, aspartame, smoke: Murray 2005.04.02
http://www.toxsci.oupjournals.org/cgi/content/full/64/2/169
Toxicological Sciences 64, 169-184 (2001)
Copyright © 2001 by the Society of Toxicology
BIOTRANSFORMATION AND TOXICOKINETIC
A Biologically Based Dynamic Model for Predicting the Disposition of Methanol and Its Metabolites in Animals and Humans<ref name="pmid11719699">{{cite journal |author=Bouchard M, Brunet RC, Droz PO, Carrier G |title=A biologically based dynamic model for predicting the disposition of methanol and its metabolites in animals and humans |journal=Toxicol. Sci. |volume=64 |issue=2 |pages=169–84 |year=2001 |pmid=11719699 |doi=}}</ref>
Michèle Bouchard *, ^,1,  [email protected]
Robert C. Brunet, ^^  [email protected]
Pierre-Olivier Droz, ^
and Gaétan Carrier *  [email protected]
* Department of Environmental and Occupational Health, Faculty of Medicine,
Université de Montréal, P.O. Box 6128, Main Station, Montréal, Québec,
Canada, H3C 3J7;
^ Institut Universitaire romand de Santé au Travail, rue du Bugnon 19,
CH-1005, Lausanne, Switzerland, and
^^  Département de Mathématiques et de Statistique and Centre de Recherches
Mathématiques, Faculté des arts et des sciences, Université de Montréal,
P.O. Box 6128, Main Station, Montréal, Québec, Canada, H3C 3J7
1 To whom correspondence should be addressed at Département de santé
environnementale et santé au travail, Université de Montréal, P.O. Box 6128,
Main Station, Montréal, Québec, H3C 3J7, Canada. Fax: (514) 343-2200.
Received May 10, 2001; accepted August 28, 2001
''<blockquote>ABSTRACT
A multicompartment biologically based dynamic model was developed to describe the time evolution of methanol and its metabolites in the whole body and in accessible biological matrices of rats, monkeys, and humans following different exposure scenarios.
The dynamic of intercompartment exchanges was described mathematically by a mass balance differential equation system.
The model's conceptual and functional representation was the same for rats, monkeys, and humans, but relevant published data specific to the species of interest served to determine the critical parameters of the kinetics.
Simulations provided a close approximation to kinetic data available in the published literature.
The average pulmonary absorption fraction of methanol was estimated to be 0.60 in rats, 0.69 in monkeys, and 0.58-0.82 in human volunteers.
The corresponding average elimination half-life of absorbed methanol through metabolism to formaldehyde was estimated to be 1.3, 0.7-3.2, and 1.7 h.
Saturation of methanol metabolism appeared to occur at a lower exposure in rats than in monkeys and humans.
Also, the main species difference in the kinetics was attributed to a metabolism rate constant of whole body formaldehyde to formate estimated to be twice as high in rats as in monkeys.
Inversely, in monkeys and in humans, a larger fraction of body burden of formaldehyde is rapidly transferred to a long-term component.
The latter represents the formaldehyde that (directly or after oxidation to formate) binds to various endogenous molecules or is taken up by the tetrahydrofolic-acid-dependent one-carbon pathway to become the building block of synthetic pathways.
This model can be used to quantitatively relate methanol or its metabolites in biological matrices to the absorbed dose and tissue burden at any point in time in rats, monkeys, and humans for different exposures, thus reducing uncertainties in the dose-response relationship, and animal-to-human and
exposure scenario comparisons.
The model, adapted to kinetic data in human volunteers exposed acutely to methanol vapors, predicts that 8-h inhalation exposures ranging from 500 to 2000 ppm, without physical activities, are needed to increase concentrations of blood formate and urinary formic acid above mean background values
reported by various authors (4.9-10.3 and 6.3-13 mg/liter, respectively).
This leaves blood and urinary methanol concentrations as the most sensitive biomarkers of absorbed methanol.
Key Words: methanol; formaldehyde; formate; toxicokinetics; modeling; animals; humans.</blockquote>''
"However, the severe toxic effects are usually associated with the production and accumulation of formic acid, which causes metabolic acidosis and visual impairment that can lead to blindness and death at blood concentrations of methanol above 31 mmol/l (Røe, 1982; Tephly and McMartin, 1984; U.S. DHHS, 1993).
Although the acute toxic effects of methanol in humans are well documented, little is known about the chronic effects of low exposure doses, which are of interest in view of the potential use of methanol as an engine fuel and current use as a solvent and chemical intermediate.
Gestational exposure studies in pregnant rodents (mice and rats) have also shown that high methanol inhalation exposures (5000 or 10,000 ppm and more, 7 h/day during days 6 or 7 to 15 of gestation) can induce birth defects (Bolon et al., 1993; IPCS, 1997; Nelson et al., 1985)."
"The corresponding average elimination half-life of absorbed methanol through metabolism to formaldehyde was estimated to be 1.3, 0.7-3.2, and 1.7 h."
"Inversely, in monkeys and in humans, a larger fraction of body burden of formaldehyde is rapidly transferred to a long-term component.
The latter represents the formaldehyde that (directly or after oxidation to formate) binds to various endogenous molecules..."
"Animal studies have reported that systemic methanol is eliminated mainly by metabolism (70 to 97% of absorbed dose) and only a small fraction is eliminated as unchanged methanol in urine and in the expired air (< 3-4%) (Dorman et al., 1994; Horton et al., 1992).
Systemic methanol is extensively metabolized by liver alcohol dehydrogenase and catalase-peroxidase enzymes to formaldehyde, which is in turn rapidly oxidized to formic acid by formaldehyde dehydrogenase enzymes (Goodman and Tephly, 1968; Heck et al., 1983; Røe, 1982; Tephly and McMartin, 1984).
Under physiological conditions, formic acid dissociates to formate and hydrogen ions.
Current evidence indicates that, in rodents, methanol is converted mainly by the catalase-peroxidase system whereas monkeys and humans metabolize methanol mainly through the alcohol dehydrogenase system (Goodman and Tephly, 1968; Tephly and McMartin, 1984).
Formaldehyde, as it is highly reactive, forms relatively stable adducts with cellular constituents (Heck et al., 1983; Røe, 1982)."
"The whole body loads of methanol, formaldehyde, formate, and unobserved by-products of formaldehyde metabolism were followed.
Since methanol distributes quite evenly in the total body water, detailed compartmental representation of body tissue loads was not deemed necessary."
"According to model predictions, congruent with the data in the literature (Dorman et al., 1994; Horton et al., 1992), a certain fraction of formaldehyde is readily oxidized to formate, a major fraction of which is rapidly converted to CO2 and exhaled, whereas a small fraction is excreted as formic acid in urine.
However, fits to the available data in rats and monkeys of Horton et al. (1992) and Dorman et al. (1994) show that, once formed, a substantial fraction of formaldehyde is converted to unobserved forms.
This pathway contributes to a long-term unobserved compartment.
The latter, most plausibly, represents either the formaldehyde that (directly or after oxidation to formate) binds to various endogenous  molecules (Heck et al., 1983; Røe, 1982) or is incorporated in the tetrahydrofolic-acid-dependent one-carbon pathway to become the building block of a number of synthetic pathways (Røe, 1982; Tephly and McMartin, 1984).
That substantial amounts of methanol metabolites or by-products are retained for a long time is verified by Horton et al. (1992) who estimated that 18 h following an iv injection of 100 mg/kg of 14C-methanol in male Fischer-344 rats, only 57% of the dose was eliminated from the body.
From the data of Dorman et al. (1994) and Medinsky et al. (1997), it can further be calculated that 48 h following the start of a 2-h inhalation exposure to 900 ppm of 14C-methanol vapors in female cynomolgus monkeys, only 23 % of the absorbed 14C-methanol was eliminated from the body.
These findings are corroborated by the data of Heck et al. (1983) showing that 40 % of a 14C-formaldehyde inhalation dose remained in the body 70 h postexposure.
In the present study, the model proposed rests on acute exposure data, where the time profiles of methanol and its metabolites were determined only over short time periods (a maximum of 6 h of exposure and a maximum of 48 h postexposure).
This does not allow observation of the slow release from the long-term components.
It is to be noted that most of the published studies on the detailed disposition kinetics of methanol regard controlled short-term (iv injection or continuous inhalation exposure over a few hours) methanol exposures in rats, primates, and humans (Batterman et al., 1998; Damian and Raabe, 1996;
Dorman et al., 1994; Ferry et al., 1980; Fisher et al., 2000; Franzblau et al., 1995; Horton et al., 1992; Jacobsen et al., 1988; Osterloh et al., 1996; Pollack et al., 1993; Sedivec et al., 1981; Ward et al., 1995; Ward and Pollack, 1996).
Experimental studies on the detailed time profiles following controlled repeated exposures to methanol are lacking."
"Thus, in monkeys and plausibly humans, a much larger fraction of body formaldehyde is rapidly converted to unobserved forms rather than passed on to formate and eventually CO2."
"However, the volume of distribution of formate was larger than that of methanol, which strongly suggests that formate distributes in body constituents other than water, such as proteins.
The closeness of our simulations to the available experimental data on the time course of formate blood concentrations is consistent with the volume of distribution concept (i.e., rapid exchanges between the nonblood pool of formate and blood formate)."
"Also, background concentrations of formate are subject to wide interindividual variations (Baumann and Angerer, 1979; D'Alessandro et al., 1994; Franzblau et al., 1995; Heinrich and Angerer, 1982; Lee et al., 1992; Osterloh et al., 1996; Sedivec et al., 1981)."


http://groups.yahoo.com/group/aspartameNM/message/1286
http://groups.yahoo.com/group/aspartameNM/message/1286
Line 615: Line 494:
http://groups.yahoo.com/group/aspartameNM/message/1496
http://groups.yahoo.com/group/aspartameNM/message/1496
explosion in numbers of children with serious food allergies has bewildered experts and parents, Helen Francombe, The Australian 2007.11.17: role of formic acid from methanol in liquors and aspartame, Murray 2007.11.28 ]
explosion in numbers of children with serious food allergies has bewildered experts and parents, Helen Francombe, The Australian 2007.11.17: role of formic acid from methanol in liquors and aspartame, Murray 2007.11.28 ]
http://www.faslink.org/Formic%20Acid%20Kapur.htm
Brief Summary:
Methanol in small amounts is present along with ethanol in beverage alcohol. [Murray: and about the same amounts from aspartame diet sodas]
The body's natural enzymes preferentially metabolize ethanol while methanol breaks down into highly neurotoxic Formic Acid.
Use of high levels of Folic Acid was found to inhibit brain damage caused by the methanol.
The use of Folic Acid during pregnancy has been recommended for several years to prevent neural tube defects.
However, this study indicates that even higher levels of Folic Acid can be very beneficial to the developing baby, particularly where alcohol exposure is a factor.
Folic Acid is mandated as an additive to all flour sold in Canada.
The debate has begun on its required addition to all beverage alcohol to help mitigate damage caused to both infants and adults.
Formic Acid in the Drinking patient and the expectant mother
Dr. Bhushan M. Kapur
Departments of Laboratory Medicine,
St. Michael's Hospital , Toronto, Ontario, Canada
Abstract
Methanol is produced endogenously in the pituitary glands of humans and is present as a congener in almost all alcoholic beverages.
Ethanol and methanol are both bio-transformed by alcohol dehydrogenase; however, ethanol has greater affinity for the enzyme.
Since ethanol is preferentially metabolized by the enzyme, it is not surprising that trace amounts of methanol, most likely originating from both sources, have been reported in the blood of people who drink alcohol.
Toxicity resulting from methanol is very well documented in both humans and animals and is attributed to its toxic metabolite formic acid.
To understand ethanol toxicity and Fetal Alcohol Spectrum Disorders, it is important to consider methanol and its metabolite, formic acid, as potential contributors to the toxic effects of alcohol.
Accumulation of methanol suggests that alcohol-drinking population should have higher than baseline levels of formic acid.
Our preliminary studies do indeed show this.
Chronic low-level exposure to methanol has been suggested to impair human visual functions.
Formic acid is known to be toxic to the optic nerve.
Ophthalmological abnormalities are a common finding in children whose mothers used alcohol during pregnancy.
Formic acid, a low molecular weight substance, either crosses the placenta or may be formed in-situ from the water soluble methanol that crosses the placenta.
Embryo toxicity from formic acid has been reported in an animal model.
To assess neurotoxicity we applied low doses of formic acid to rat brain hippocampal slice cultures.
We observed neuronal death with a time and dose response.
Formic acid requires folic acid as a cofactor for its elimination.
Animal studies have shown that when folate levels are low, the elimination of formic acid is slower and formate levels are elevated.
When folic acid was added along with the formic acid to the brain slice cultures, neuronal death was prevented.
Therefore, folate deficient chronic drinkers may be at higher risk of organ damage.
Women who are folic acid deficient and consume alcohol may have higher levels of formic acid and should they become pregnant, their fetus may be at risk.
To our knowledge low level chronic exposure to formic acid and its relationship to folic acid in men or women who drink alcohol has never been studied.
Our hypothesis is that the continuous exposure to low levels of formic acid is toxic to the fetus and may be part of the etiology of Fetal Alcohol Spectrum Disorders.
http://www.blackwell-synergy.com/doi/abs/10.1111/j.1530-0277.2007.00541.x
Alcoholism: Clinical and Experimental Research
Volume 31 Issue 12 Page 2114-2120, December 2007
Bhushan M. Kapur,  [email protected],
Arthur C. Vandenbroucke, PhD, FCACB
Yana Adamchik,
Denis C. Lehotay,  [email protected],
Peter L. Carlen  [email protected],
(2007) Formic Acid, a Novel Metabolite of Chronic Ethanol Abuse, Causes Neurotoxicity, Which Is Prevented by Folic Acid
Alcoholism: Clinical and Experimental Research 31 (12), 2114–2120.
doi:10.1111/j.1530-0277.2007.00541.x
From:
the Department of Clinical Pathology (BMK),
Sunnybrook Health Science Centre, Division of Clinical Pharmacology and Toxicology, The Hospital for Sick Children, Toronto, Ontario, Canada;
St. Michael’s Hospital (ACV), Toronto, Canada; Department of Laboratory Medicine and Pathobiology (BMK, ACV),
Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada;
Departments of Medicine (Neurology) and Physiology (YA, PLC),
Toronto Western Research Institute, University of Toronto,
Toronto, Ontario, Canada;
and University of Saskatchewan (DLC), Saskatchewan, Canada.
Reprint requests: Dr. Bhushan M. Kapur, Department of Clinical Pathology, Sunnybrook Health Science Centre, 2075 Bayview Ave,
Toronto, Ontario, M4N 3M5, Canada; Fax: 416-813-7562; E-Mail: [email protected],
Abstract
Background: Methanol is endogenously formed in the brain and is present as a congener in most alcoholic beverages.
Because ethanol is preferentially metabolized over methanol (MeOH) by alcohol dehydrogenase, it is not surprising that MeOH accumulates in the alcohol-abusing population.
This suggests that the alcohol-drinking population will have higher levels of MeOH’s neurotoxic metabolite, formic acid (FA).
FA elimination is mediated by folic acid.
Neurotoxicity is a common result of chronic alcoholism.
This study shows for the first time that FA, found in chronic alcoholics, is neurotoxic
and this toxicity can be mitigated by folic acid administration.
Objective:
To determine if FA levels are higher in the alcohol-drinking population and to assess its neurotoxicity in organotypic hippocampal rat brain slice cultures.
Methods:
Serum and CSF FA was measured in samples from both ethanol abusing and control patients, who presented to a hospital emergency department.
FA’s neurotoxicity and its reversibility by folic acid were assessed using organotypic rat brain hippocampal slice cultures using clinically relevant concentrations.
Results:
Serum FA levels in the alcoholics
(mean ± SE: 0.416 ± 0.093 mmol/l, n = 23) were significantly higher than in controls (mean ± SE: 0.154 ± 0.009 mmol/l, n = 82) (p < 0.0002).
FA was not detected in the controls’ CSF (n = 20),
whereas it was >0.15 mmol/l in CSF of 3 of the 4 alcoholic cases.
Low doses of FA from 1 to 5 mmol/l added for 24, 48 or 72 hours to the rat brain slice cultures caused neuronal death as measured by propidium iodide staining.
When folic acid (1 ?mol/l) was added with the FA, neuronal death was prevented.
Conclusions:
Formic acid may be a significant factor in the neurotoxicity of ethanol abuse.
This neurotoxicity can be mitigated by folic acid administration at a clinically relevant dose.
http://www.uhnresearch.ca/researchers/profile.php?lookup=801
Peter L Carlen, FRCPC, MD
Head, Division of Fundamental Neurobiology
Toronto Western Research Institute (TWRI)
Senior Scientist, Division of Fundamental Neurobiology
Toronto Western Research Institute (TWRI)
Keywords: stroke, gap junctions, synaptic transmission, mitochondria, calcium chelators, whole cell patch clamp recordings, fluorescence imaging, epilepsy, dementia, fetal alcohol syndrome, brain state classification
Research Interests:
Mechanisms of neural synchrony and entrainment (epilepsy), and neurodegenerative processes
We have several projects on cellular mechanisms of epilepsy, particularly the synchronizing role of electrotonic coupling via gap junctions.
Molecular biological and cellular electrophysiological recording techniques are being used to measure the upregulation of gap junctional function in several in vitro seizure models, including the use of the intact mouse hippocampus preparation.
Also a project on the pathogenesis of hypoglycemic seizures is in progress.
In collaboration with Drs. Berj Bardakjian and Frances Skinner, the linear and nonlinear electrical and network properties of central mammalian neurons in physiological and pathophysiological conditions (e.g., epilepsy) are being described by neural modelling techniques.
We are developing nonlinear techniques for the identification different brain states including those associated with anesthesia and epilepsy.
In models of stroke and Alzheimer's disease, calcium homeostasis and free radical production are under investigation, focusing on the role of degenerating mitochondrial function in presynaptic terminals.
Fluorescence and confocal microscopic imaging of intracellular calcium and mitochondrial function coupled with whole cell and field electrophysiological recordings are being used.
In collaboration with Drs. Bhushan Kapur, James Reynolds and James Brien, we are examining the role of formic acid in the causation of the brain damage in the fetal alcohol spectrum disorder and its rescue by folate.
Peter L Carlen
Mailing Address
Primary Office
Toronto Western Hospital, McLaughlin Pavilion, 12th Floor Rm. 413
399 Bathurst St., Toronto, Ontario  Canada M5T 2S8
Phone Numbers  416.603.5800 x5044
Staff and Trainees:
Yana Adamchik
Marija Cotic
Youssef El-Hayek
S Sabet Jahromi
Eunji (Ellen) Kang
Borna Kavousi
Philip Liang
Shanthi Mylvaganam
Marina Samoilova
Evan Sheppy
Damian Shim
Alexandre Tonkikh
Hui Ye
Wilson Yu
Zhang (Jane) Zhang
http://www.clinpharmtox.utoronto.ca/Page60.aspx
Dr. Bhushan Kapur
Selected Publications
Kapur BM. Drug Testing Methods and Clinical Interpretation of Test Results. In: Carson-Dewitt R, ed. Encyclopedia of Drugs, Alcohol and Addictive Behaviour. Vol 1. Macmillian Press; 2001, p. 450-461.
Kapur B, Hackman R, Selby P, Klein J, Koren G.
A randomized, double-blind placebo control trial of nicotine replacement therapy in pregnancy. Current Therapeutic Research 2001; 62(4): 274-278.
Bailey B, Lalkin A, Kapur B, Koren G. Is chronic poisoning with acetaminophen in children a frequent occurrence in Toronto?
Can J Clin Pharmacol 2001; 8(2): 96-101. [Read More]
Ho E, Collantes A, Kapur B, Moretti M, Koren G.  Alcohol and breast feeding: Calculation of time to reach zero-level in milk.
Biol Neonate 2001; 80(3): 219-222. [Read More]
[  Dr. Gideon Koren
Division of Clinical Pharmacology and Toxicology, Hospital for Sick Children, 555 University Ave., Toronto, Ont. M5G 1X8 (Canada)
Tel. +1 416 813 5781, Fax +1 416 813 7562
Kapur B, Koren G. Folic acid fortification of flour: three years later. Can J Clin Pharmacol 2001; 8(2): 91-92. [Read More]
Ahn E, Kapur B, Koren G. Iron bioavailability in prenatal multivitamin supplements with separated and combined iron and calcium.
J Obstet Gynaecol Can 2004; 26(9):809-14. [Read More]
Railton CJ, Kapur B, Koren G. Subtherapeutic risperidone serum concentrations in an adolescent during hemodialysis: A pharmacological puzzle.
Ther Drug Monit 2005; 27(5):558-561. [Read More]
Lehotay DC, George S, Etter ML, Graybiel K, Eichhorst JC, Fern B, Wildenboer W, Selby P, Kapur B.
Free and bound enantiomers of methadone and its metabolite, EDDP in methadone maintenance treatment: Relationship to dosage?
Clin Biochem 2005; 38(12): 1088-1094. [Read More]
Langman L, Kapur B. Toxicology-then and now.
Clin Biochem 2006; 39(5):498-510.
Kapur BM, Vandenbroucke A, Adamchik Y,  Lehotay DC,  Carlen PL.
Formic acid, a novel metabolite of chronic ethanol abuse: neurotoxicity and its prevention by folic acid.
Submitted to Alcohol Clin Exp Res, April 30, 2007.
http://www.medicalnewstoday.com/articles/45698.php
Queen's-led Network Looks At FAS Aiming To Minimize Life-long Learning Problems
Main Category: Pregnancy / Obstetrics News
Article Date: 24 Jun 2006 - 12:00 PDT
====Fetal Alcohol Spectrum Disorders====
For the first time researchers are testing to see whether fetal exposure to methanol, a contaminant found in many alcoholic beverages, plays an important role in causing the life-long learning and behavioural problems associated with [[Fetal Alcohol Spectrum Disorders]] (FASD).
By understanding fetal brain injury caused by exposure to methanol and related toxins, an emerging team of researchers is laying the groundwork for potential new therapeutic interventions to protect fetuses at risk for FASD.
"The main goal will always be prevention of FASD," says lead researcher James Reynolds, Queen's University professor of Toxicology and Pharmacology, "but we also have to develop strategies to minimize injury to the developing fetus and individualize earlier therapeutic interventions for children with pre-natal exposure to alcohol."
The interdisciplinary research team, which also includes
James Brien and Doug Munoz from Queen's,
Peter Carlen (University Health Network),
Bhushan Kapur (Sunnybrook Hospital)
and Brenda Stade (St. Michael's Hospital) from Toronto,
received just under $1.5 million dollars in funding
from the Canadian Institutes of Health Research.
The Queen's researchers have found that simple eye movement tasks can be used to assess brain function in children with FASD. Since this technology is portable, the researchers plan to travel across the country to bring the research program into affected communities. "It's estimated that the incidence of FASD is about one per cent in the general population," Dr. Reynolds says, "but there are regions and communities in this country where the population affected by FASD increases dramatically."
Using blood samples from at risk mother-baby pairs, the Toronto team members hope to identify biological markers that may predict brain injury in the child. At risk babies will be tracked for 24 months following birth so researchers can identify early signs of FASD and develop aggressive therapeutic interventions at earlier stages to minimize the effects on a child's development.
To understand the underlying mechanisms of this novel hypothesis of FASD, the Toronto team members are studying the effects of formic acid and folic acid on the biological functions and survival of neurons in isolated brain tissue. In parallel studies, the Kingston team will assess the efficacy of folic acid supplementation as a potential therapeutic intervention in preventing FASD.
For these researchers, an exciting opportunity has been created by linking this study with Queen's University's state-of-the-art Magnetic Resonance Imaging (MRI) facility. New experimental procedures being developed at Queen's will link eye movement tasks to MRI images of the brain, creating an objective and much more specific way to evaluate brain function. By isolating individual brain responses, FASD researchers hope to gain greater insight into the underlying brain injury caused by prenatal exposure to alcohol, leading to more specific intervention therapies designed to minimize the affects of FASD.
"Not all children exposed to alcohol during prenatal life develop FASD," adds Dr. Reynolds. "There are other contributing factors including genetic predisposition and nutrition during gestation that make important contributions to the ultimate outcome. We need a way to identify the different sub-groups within the FASD spectrum. This research will help us develop the standardized tools we need to evaluate and treat children with FASD."
----------------------------
Article adapted by Medical News Today from original press release.
----------------------------
Contacts:
Lorinda Peterson, 613-533-3234, [email protected],
Nancy Dorrance, 613-533-2869, [email protected],
Contact: Lorinda Peterson
name: James N Reynolds
phone: 613 533 6946
campus_extension: 36946
department: Pharmacology and Toxicology
type: Faculty
name: James F Brien
phone: 613 533 6114
campus_extension: 36114
department: Pharmacology and Toxicology, School of Medicine, Psychiatry
type: Faculty
Dr. Douglas P. Munoz  [email protected],
Canada Research Chair in Neuroscience
Director, Centre for Neuroscience Studies
Professor of Physiology and Psychology
Member, CIHR Group in Sensory-Motor Systems
Queen's University, Kingston, Ontario, Canada K7L 3N6
Phone: (613) 533-2111  Fax: (613) 533-6840
Dr. Brenda Stade St. Michael’s Hospital Fetal Alcohol Spectrum Disorder Diagnostic Clinic 61 Queen Street Toronto, Ontario M5B 1W8
Tel: (416) 867- 3655  [email protected],
http://www.faslink.org/index.htm


http://www.faslink.org/toc2.htm
http://www.faslink.org/toc2.htm

Revision as of 23:48, 20 December 2007

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Aspartame is an artificial sweetener par excellence, in terms of its world market share, coupled with 26 years of intractable, polarized controversy about its safety, since its approval by the USA FDA for dry foods in July, 1981, and then for beverages in July, 1983.

As a dipeptide, its molecule is made of two normal, essential amino acids, phenylalanine (50 % by weight) and aspartic acid, (39 %), loosely bound together by a smaller methyl unit (11 %).

At temperatures above body heat, and at high levels of acidity (low pH), and soon after ingestion, it readily splits and releases its three components, which follow largely independent paths in humans.

Each molecule of aspartame releases one molecule of each of the three parts.

Methanol

The methyl unit becomes methanol, better known as wood alcohol, CH3OH, which is uaually an impurity in alcohol beverages, especially dark wines and liquors, at a level above 100 mg/l, one part in 10,000 by weight.

Methanol itself is not very toxic. Its harm results from the rapid conversion of it by the body into formaldehyde and thence largely into formic acid, with about 40 % of the methanol remaining as these two durable, cumulative toxic reaction products.

An enzyme, alcohol dehydrogenase, converts most methanol in blood into formaldehyde, a toxin, and much of the formaldehyde is soon made into formic acid, another toxin, and much of that eliminated as water and carbon dioxide.

However, the enzyme first is tied up with any available ethanol, C2H5OH, turning it into acetaldehyde, also toxic, until, after all the available ethanol is gone, the enzyme then quickly turns any methanol into formaldehyde.

Two teams published research in 1987 and 2005, showing that methanol in alcohol beverages taken before bedtime, resulted in hangover symptoms, especially headache, in healthy young students as long as 13 hours later, when the ethyl alcohol was all gone, but the remaining methanol was rapidly becoming formaldehyde.

The aspartame content of two liters diet soda, 5.6 12-oz cans, is 1,120 mg, releasing 11 % as 123 mg methanol.

Usually, there is not a concurrent larger amount of ethanol taken, which would prevent the production of formaldehyde.

So, the methanol from any aspartame is quickly turned into formaldehyde and formic acid.

An expert review by a competent, unbiased team led by M. Bouchard, 2001, cites references, many from aspartame industry funded studies, states that about 30 - 40 % of the methanol remains in the body as unknown, durable reaction products.

J. Nutrition 1973 Oct; 103(10): 1454-1459. Metabolism of aspartame in monkeys.[1] Oppermann JA, Muldoon E, Ranney RE. Dept. of Biochemistry, Searle Laboratories, Division of G.D. Searle and Co. Box 5110, Chicago, IL 60680

They found that about 70 % of the radioactive methanol in aspartame put into the stomachs of 3 to 7 kg monkeys was eliminated within 8 hours, with little additional elimination, as carbon dioxide in exhaled air and as water in the urine

They did not report any studies on the distribution of radioactivity in body tissues, except that blood plasma proteins after 4 days held 4 % of the initial methanol.

The low oral dose of aspartame and for methanol was 0.068 mmol/kg, about 1 part per million [ppm] of the acute toxicity level of 2,000 mg/kg, 67,000 mmol/kg, used by McMartin (1979).

Two L daily use of diet soda provides 123 mg methanol, 2 mg/kg for a 60 kg person, a dose of 67 mmole/kg, a thousand times more than the dose in this study.

By eight hours excretion of the dose in air and urine had leveled off at 67.1 +-2.1 % as CO2 in the exhaled air and 1.57+-0.32 % in the urine, so 68.7 % was excreted, and 31.3 % was retained.

This data is the average of 4 monkeys. "...the 14C in the feces was negligible."

"That fraction not so excreted (about 31%) was converted to body constituents through the one-carbon metabolic pool." "All radioactivity measurements were counted to +-1 % accuracy..."

The abstract ends, "It was concluded that aspartame was digested to its three constituents that were then absorbed as natural constituents of the diet."



http://health.groups.yahoo.com/group/aspartameNM/message/1143

http://www.toxsci.oupjournals.org/cgi/content/full/64/2/169


"Exposure to methanol also results from the consumption of certain foodstuffs (fruits, fruit juices, certain vegetables, aspartame sweetener, roasted coffee, honey) and alcoholic beverages (Health Effects Institute, 1987; Jacobsen et al., 1988)."

"Experimental studies on the detailed time profiles following controlled repeated exposures to methanol are lacking."

"Thus, in monkeys and plausibly humans, a much larger fraction of body formaldehyde is rapidly converted to unobserved forms rather than passed on to formate and eventually CO2."

"However, the volume of distribution of formate was larger than that of methanol, which strongly suggests that formate distributes in body constituents other than water, such as proteins."

http://groups.yahoo.com/group/aspartameNM/message/1143

http://groups.yahoo.com/group/aspartameNM/message/1286

Methanol in alcohol abuse-related disorders

methanol products (formaldehyde and formic acid) are main cause of alcohol hangover symptoms [same as from similar amounts of methanol, the 11% part of aspartame]: YS Woo et al, 2005 Dec: Murray 2006.01.20

Addict Biol. 2005 Dec;10(4): 351-5. Concentration changes of methanol in blood samples during an experimentally induced alcohol hangover state. Woo YS, Yoon SJ, Lee HK, Lee CU, Chae JH, Lee CT, Kim DJ. Chuncheon National Hospital, Department of Psychiatry, The Catholic University of Korea, Seoul, Korea. [ Han-Kyu Lee ]

A hangover is characterized by the unpleasant physical and mental symptoms that occur between 8 and 16 hours after drinking alcohol.

After inducing experimental hangover in normal individuals, we measured the methanol concentration prior to and after alcohol consumption and we assessed the association between the hangover condition and the blood methanol level.

A total of 18 normal adult males participated in this study.

They did not have any previous histories of psychiatric or medical disorders.

The blood ethanol concentration prior to the alcohol intake (2.26+/-2.08) was not significantly different from that 13 hours after the alcohol consumption (3.12+/-2.38).

However, the difference of methanol concentration between the day of experiment (prior to the alcohol intake) and the next day (13 hours after the alcohol intake) was significant (2.62+/-1.33/l vs. 3.88+/-2.10/l, respectively).

[ So, the normal methanol level was 2.62 mg per liter, and increasing that by 50% = 1.3 mg per liter to 3.88 mg per liter caused hangover symptoms.

The human body has about 5.6 liters blood, so adding 1.3 mg per liter gives an estimate of 7.3 mg added methanol, as much as 4 oz diet soda.

Diet soda is about 200 mg aspartame per 12 oz can, which is 22 mg (11% methanol), 1.83 mg methanol per ounce.

Also, this 50 % increase in blood methanol that caused roughly similar symptoms in South Koreans, Woo YS, 2005, as in men in Swedem who had a 6-fold increase in urine methanol, confirms many studies that show that specific genetic differences make Asians and American Indians much more vulnerable to inebriation, hangover, and addiction than Europeans. Bendtsen P, Jones AW, Helander A. 1998 ]

A significant positive correlation was observed between the changes of blood methanol concentration and hangover subjective scale score increment when covarying for the changes of blood ethanol level (r=0.498, p<0.05).

This result suggests the possible correlation of methanol as well as its toxic metabolite to hangover. PMID: 16318957

The role of formaldehyde and formic acid

[ The "toxic metabolite" of methanol is formaldehyde, which in turn partially becomes formic acid -- both potent cumulative toxins that are the actual cause of the toxicity of methanol.]


Int J Neurosci. 2003 Apr; 113(4): 581-94.

The effects of alcohol hangover on cognitive functions in healthy subjects.[2] Kim DJ, Yoon SJ, Lee HP, Choi BM, Go HJ. Department of Psychiatry, College of Medicine, Catholic University of Korea, Buchon City, Kyunggi Do, Korea.

A hangover is characterized by the constellation of unpleasant physical and mental symptoms that occur between 8 and 16 h after drinking alcohol.

We evaluated the effects of experimentally-induced alcohol hangover on cognitive functions using the Luria-Nebraska Neuropsychological Battery.

A total of 13 normal adult males participated in this study.

They did not have any previous histories of psychiatric or medical disorders.

We defined the experimentally-induced hangover condition at 13 h after drinking a high dose of alcohol (1.5 g/kg of body weight).

We evaluated the changes of cognitive functions before drinking alcohol and during experimentally-induced hangover state.

The Luria-Nebraska Neuropsychological Battery was administrated in order to examine the changes of cognitive functions.

Cognitive functions, such as visual, memory, and intellectual process functions, were decreased during the hangover state.

Among summary scales, the profile elevation scale was also increased.

Among localization scales, the scores of left frontal, sensorimotor, parietal-occipital dysfunction, and right parietal-occipital scales were increased during the hangover state.

These results indicate that alcohol hangovers have a negative effect on cognitive functions, particularly on the higher cortical and visual functions associated with the left hemisphere and right posterior hemisphere. Publication Types: Clinical Trial PMID: 12856484


Alcohol Alcohol. 1998 Jul-Aug; 33(4): 431-8.

Urinary excretion of methanol and 5-hydroxytryptophol as biochemical markers of recent drinking in the hangover state.[3] [email protected] Bendtsen P, Jones AW, Helander A. [email protected] Drug Dependence Unit, University Hospital, Linkoping, Sweden.

Twenty healthy social drinkers (9 women and 11 men) drank either 50 g of ethanol (mean intake 0.75 g/kg) or 80 g (mean 1.07 g/kg) according to choice as white wine or export beer in the evening over 2 h with a meal.

After the end of drinking, at bedtime, in the following morning after waking-up, and on two further occasions during the morning and early afternoon, breath-alcohol tests were performed and samples of urine were collected for analysis of ethanol and methanol and the 5-hydroxytryptophol (5-HTOL) to 5-hydroxyindol-3-ylacetic acid (5-HIAA) ratio.

The participants were also asked to quantify the intensity of hangover symptoms (headache, nausea, anxiety, drowsiness, fatigue, muscle aches, vertigo) on a scale from 0 (no symptoms) to 5 (severe symptoms).

The first morning urine void collected 6-11 h after bedtime as a rule contained measurable amounts of ethanol, being 0.09 +/- 0.03 g/l (mean +/- SD) after 50 g and 0.38 +/- 0.1 g/l after 80 g ethanol.

The corresponding breath-alcohol concentrations were zero, except for three individuals who registered 0.01-0.09g/l.

Ethanol was not measurable in urine samples collected later in the morning and early afternoon.

The peak urinary methanol occurred in the first morning void, when the mean concentration after 80 g ethanol was approximately 6-fold higher than pre-drinking values.

[ This is a much greater increase of methanol than the 50 % increase that cause roughly similar symptoms in South Koreans, Woo YS, 2005, confirming many studies that show that specific genetic differences make Asians and American Indians much more vulnerable to inebriation, hangover, and addiction. ]

This compares with a approximately 50-fold increase for the 5-HTOL/5-HIAA ratio in the first morning void.

Both methanol and the 5-HTOL/5-HIAA ratio remained elevated above pre-drinking baseline values in the second and sometimes even the third morning voids.

Most subjects experienced only mild hangover symptoms after drinking 50 g ethanol (mean score 2.4 +/- 2.6), but the scores were significantly higher after drinking 80 g (7.8 +/- 7.1).

The most common symptoms were headache, drowsiness, and fatigue.

A highly significant correlation (r = 0.62-0.75, P <0.01) was found between the presence of headache, nausea, and vertigo and the urinary methanol concentration in the first and second morning voids, whereas 5-HTOL/5-HIAA correlated with headache and nausea.

These results show that analysing urinary methanol and 5-HTOL furnishes a way to disclose recent drinking after alcohol has no longer been measurable by conventional breath-alcohol tests for at least 5-10 h.

The results also support the notion that methanol may be an important factor in the aetiology of hangover. PMID: 9719404


http://groups.yahoo.com/group/aspartameNM/message/1373

Drug-metabolizing enzymes

aspartame rat brain toxicity re cytochrome P450 enzymes, expecially CYP2E1, Vences-Mejia A, Espinosa-Aguirre JJ et al, 2006 Aug, Hum Exp Toxicol: relevant abstracts re formaldehyde from methanol in alcohol drinks: Murray 2006.09.29

[ Rich Murray notes: As a medical layman, noting that all readers are laymen for any topic outside the bounds of their specific expertise, I found related abstracts that illucidate the role of cytochrome P450 enzymes, especially the one most affected by aspartame, CYP2E1, in brain toxicity processes involving ethanol and methanol, suggesting avenues of research for alcohol addiction and hangover, and the possibilies of aspartame liver and brain toxicity from its 11 % methanol component. ]

"A major finding in this study was that the daily consumption of ASP at the two doses considered leads to an increment in the concentration and activity of CYP2B1/2, CYP2E1 and CYP3A2 in rat cerebral and cerebellar microsomes....

The highest increment (up to 25-fold over controls) in a CYP-associated activity induced by ASP in brain was that of 4-NPH corresponding to CYP2E1.

The results mentioned above must be reproduced using a broad range of ASP concentrations in order to define the existence of a dose-related effect.

As far as we know, this is the first report regarding modulation of brain CYPs by the widely used sweetener ASP.

Specific induction of brain CYPs could constitute a local regulatory mechanism of enzyme activity, thus influencing drug response; for tissues exhibiting low regenerative capacity, such as the brain, such modulation would probably be of major toxicological significance....

It has already been said that once ASP enters the organism, it is rapidly metabolized by intestinal esterases and dipeptidases to aspartic acid, phenylalanine and methanol, substances normally found in the diet and body. 37

One hour after ASP intake at a dose of 200 mg/kg body weight by rats, corresponding to the acceptable FDA daily intake for the sweetener after species correction, increased plasma and brain phenylalanine levels by 62 % and 192 % respectively. 6

With regard to methanol, it accounts for about 10 % of the ASP weight administered. 38

We can hypothesize that the exposure to methanol at the two regimens used in this study ( about 7.5 and 12.5 mg/kg from the doses of 75 and 125 mg/kg ) could induce xenobiotic-metabolizing enzymes in a similar way to that of the chronic administration of ethanol. 39....

If methanol is the metabolite responsible for the induction of brain CYP2E1 seen in this work, the question of why the hepatic CYP2E1 was not altered remains.

Experiments with the three metabolites resulting from ASP metabolism are currently being undertaken in our laboratory in order to address this question.

In conclusion, data obtained demonstrated that a daily consumption of ASP at doses of 75 and 125 mg/kg body weight over 30 days provokes a substantial increment in CYP enzymes involved in endogenous and exogenous molecules metabolism in the CNS of the rat.

Biological consequences of this phenomenon should be investigated in view of the high number of humans exposed to this artificial sweetener and because of the recent data indicating the potential carcinogenic effects of this compound. 41"

"The aim of this study was to explore the effect of orally ingested ASP upon the expression and activity of CYP families involved in the CNS of rats.

The chosen ASP doses of 75 and 125 mg/kg body weight used in this study are within the limits of human consumption after species factor correction.

Because rats metabolize ASP faster than humans, 31 dose comparisons between them have usually been corrected by a factor of 5.

After correction, doses used here are below the FDA (50 mg/kg body weight) and Health and Welfare Canada (40 mg/kg body weight) acceptable daily intake for ASP. 32,33"


Hum Exp Toxicol. 2006 Aug; 25(8): 453-9. The effect of aspartame on rat brain xenobiotic-metabolizing enzymes.

Vences-Mejia A 1,

Labra-Ruiz N 1,

Hernandez-Martinez N 1,

Dorado-Gonzalez V 1,

Gomez-Garduno J 1,

Perez-Lopez I 1,

Nosti-Palacios R 1,

Camacho Carranza R 2,

Espinosa-Aguirre JJ 2.

Laboratorio de Toxicologia Genetica,

1: Instituto Nacional de Pediatria, Insurgentes Sur, 3700-C, 04530 Mexico, DF Mexico.

2: Instituto de Investigaciones Biomédicas, UNAM, Apartado postal 70228, Ciudad Universitaria 04510 México, D.F., México

http://www.biomedicas.unam.mx/index.asp

  • Correspondence: JJ Espinosa-Aguirre, Instituto de Investigaciones Biome´dicas, UNAM, Apartado postal 70228, Ciudad Universitaria 04510 Me´xico, D.F., Me´xico

Human & Experimental Toxicology (2006) 25(8): 453-459.

www.sagepublications.com c 2006 SAGE Publications 10.1191/0960327106het646oa

[ Dra. Araceli Vences M

Jefa de Laboratorio de Toxicologia Genetica, 6° P de Hospital Laboratorios, 10 84 09 00 Ext.1410 -1448 [email protected]

ISRAEL PÉREZ LÓPEZ,

JAVIER J. ESPINOSA AGUIRRE, [email protected]

http://www.biomedicas.unam.mx/investigacionFrame.asp?ID=MG ]

Abstract

This study demonstrates that chronic aspartame (ASP) consumption leads to an increase of phase I metabolizing enzymes (cytochrome P450 (CYP)) in rat brain.

Wistar rats were treated by gavage with ASP at daily doses of 75 and 125 mg/kg body weight for 30 days.

Cerebrum and cerebellum were used to obtain microsomal fractions to analyse activity and protein levels of seven cytochrome P450 enzymes.

Increases in activity were consistently found with the 75 mg/kg dose both in cerebrum and cerebellum for all seven enzymes, although not at the same levels:

CYP2E1-associated 4-nitrophenol hydroxylase (4-NPH) activity was increased 1.5-fold in cerebrum and 25-fold in cerebellum;

likewise, CYP2B1-associated penthoxyresorufin O-dealkylase (PROD) activity increased 2.9- and 1.7-fold respectively,

CYP2B2-associated benzyloxyresorufin O-dealkylase (BROD) 4.5- and 1.1-fold,

CYP3A-associated erythromycin N-demethylase (END) 1.4- and 3.3-fold,

CYP1A1-associated ethoxyresorufin O-deethylase (EROD) 5.5- and 2.8-fold,

and CYP1A2-associated methoxyresorufin O-demethylase (MROD) 3.7- and 1.3-fold.

Furthermore, the pattern of induction of CYP immunoreactive proteins by ASP paralleled that of 4-NHP-, PROD-, BROD-, END-, EROD- and MROD-related activities only in the cerebellum.

Conversely, no differences in CYP concentration and activity were detected in hepatic microsomes of treated animals with respect to the controls, suggesting a brain-specific response to ASP treatment. PMID: 16937917 Aug 14 2006 08:07:58

Key words: aspartame; brain; cytochrome P450; enzyme induction

Introduction

Sweeteners are paid special attention among food additives, as their use enables a sharp reduction in sugar consumption and a significant decrease in caloric intake while maintaining the desirable palatability of foods and soft drinks.

Sweeteners are also of primary importance as part of nutritional guidance for diabetes, a disease with increasing incidence in developed countries. 1-3

Aspartame (L-asparthyl-L-phenylalanine methyl ester, ASP) is one of the most widely used artificial sweeteners; it is a high-intensity sweetener added to a large variety of foods, most commonly found in low-calorie beverages, desserts and tabletop sweeteners added to tea or coffee.

It does not enter into the bloodstream intact, but is hydrolyzed in the intestine to form aspartate, phenylalanine and methanol, which are then absorbed into the circulation, elevating their levels in plasma and in brain phenylalanine and tyrosine levels as well. 4-6

Aspartate is a highly excitatory neurotransmitter 7 and phenylalanine is a precursor of catecholamines in the brain; 8 increased levels of these molecules could change the basic activity level of the brain to an unhealthy, constantly stimulated state.

Short-term studies on ASP consumption and memory loss have been conducted in humans and rodents and no relationship was found. 9-11

On the other hand, chronic studies have implicated ASP consumption in learning and memory.

Consumption of 9% ASP in the diet for 13 weeks affected learning behaviour in male rats, 12 while ASP exposure of guinea pigs to 500 mg/kg during gestation disrupted odour-associative learning in pups. 13

Recently, Christian et al. reported that chronic ASP consumption lengthened the time it took rats to find the reward in a T-maze and increased the number of muscarinic receptors in specific brain areas. 14

[ 12 Potts WJ, Bloss JL, Nutting EF. Biological properties of aspartame: I. Evaluation of central nervous system effects. J Environ Pathol Toxicol 1980; 3: 341=353.�

13 Dow-Edwards DL, Scribani LA, Riley EP. Impaired performance on odor-aversion testing following prenatal aspartame exposure in the guinea pig. Neurotoxicol Teratol 1989; 11: 413-416.

14 Christian B, McConnaughey K, Bethea E, Brantley S, Coffey A, Hammond L, et al. Chronic aspartame affects T-maze performance, brain cholinergic receptors and Na�, K�-ATPase in rats. P Pharmacol Biochem Behav 2004; 78: 121-127. ]


Despite numerous toxicological studies of ASP and its components, its effects on metabolic and detoxification enzyme systems have received little attention.

Metabolic enzymes are of special interest as changes in their function could lead to an increased susceptibility of the organisms to the harmful effects of a variety of contaminants found in the environment and in food products. 15,16

The presence of cytochrome P450 (CYP) in the central nervous system (CNS) opens the question of whether metabolism in endothelial cells may regulate the penetration of the xenobiotics into the brain compartment. 17,18

The role of CYP in brain includes such diverse functions as aromatization of androgens to oestrogens, formation of catechols, and it may also participate in the metabolism of neurotransmitters and of xenobiotics. 17,19

Moreover, lipophilic xenobiotics can diffuse through the endothelial cells of the brain capillaries and enter the neuronal cells.

Thus, in situ activation in the neuronal cell could have far-reaching consequences by causing irreversible disruption of the neuronal function.

The brain is the target not only for a number of toxic compounds but also for several psychoactive drugs.

The metabolism of drugs in the brain can lead to local pharmacological modulation at the site of action and can result in variable drug response. 17

The purpose of this work is to study the effect of orally administered ASP on the activity of CYP in the CNS of the rat.

The characterization of brain specific CYP and its regulation and localization within the CNS is gaining importance for the understanding of the potential role of these enzymes in the pathogenesis of neurodegenerative disorders and in the psychopharmacological modulation of drugs acting on the CNS. 17



Free Radic Res. 1997 Oct; 27(4): 369-75. Decreased antioxidant defense mechanisms in rat liver after methanol intoxication.

Skrzydlewska E,

Farbiszewski R.

Department of Instrumental Analysis, Medical Academy, Poland.

The primary metabolic fate of methanol is oxidation to formaldehyde and then to formate by enzymes of the liver.

Cytochrome P-450 and a role for the hydroxyl radical have been implicated in this process.

The aim of the paper was to study the liver antioxidant defense system in methanol intoxication, in doses of 1.5, 3.0 and 6.0 g/kg b.w., after methanol administration to rats.

In liver homogenates, the activities of Cu,Zn-superoxide dismutase and catalase were significantly increased after 6 h following methanol ingestion in doses of 3.0 and 6.0 g/kg b.w. and persisted up to 2-5 days, accompanied by significant decrease of glutathione reductase and glutathione peroxidase activities.

The content of GSH was significantly decreased during 6 hours to 5 days.

The liver ascorbate level was significantly diminished, too, while MDA levels were considerably increased after 1.5, 3.0 and 6.0 g/kg b.w. methanol intoxication.

Changes due to methanol ingestion may indicate impaired antioxidant defense mechanisms in the liver tissue. PMID: 9416465


Wien Klin Wochenschr. 1988 Apr 29; 100(9): 282-8. [Methanol--an up-to-now neglected constituent of all alcoholic beverages. A new biochemical approach to the problem of chronic alcoholism] [Article in German]

Sprung R,

Bonte W,

Lesch OM.

Institut fur Rechtsmedizin, Universitat Gottingen.

Alcoholism is usually understood as ethanolism.

There is some evidence that its oxidation product acetaldehyde may condense with endogenous amines to form tetrahydroisoquinoline (TIQ) and - tetrahydro-beta-carboline (THBC) alkaloids which ultimately might be responsible for addiction.

In most animal experiments pure ethanol solutions were fed, but chronic alcoholics prefer normal alcoholic beverages, and it is widely ignored that all these beverages without exception also contain methanol.

Its metabolite formaldehyde is a much more potent reaction partner for TIQ and THBC formation than acetaldehyde.

As our findings in chronic alcoholics proved that these persons in contrast to healthy subjects are able to oxidize methanol despite high ethanol levels, there must be a continuous leakage of formaldehyde.

And it seems possible that methanol plays a more significant role in the pathophysiology and possibly the etiology of chronic alcoholism than ethanol. PMID: 3291400


Wien Klin Wochenschr. 1991; 103(22): 684-9.

[Methanol metabolism in chronic alcoholism] [Article in German]

Soyka M,

Gilg T,

von Meyer L,

Ora I.

Psychiatrische Klinik, Universitat Munchen.

Serum methanol concentrations (SMC) exceeding 10 mg/l are highly suggestive of long-term alcohol intoxication and can be considered as marker for chronic alcohol abuse.

Endogenously formed or consumed methanol is almost exclusively metabolized by alcohol dehydrogenase.

As long as blood alcohol concentrations exceed 0.2-0.5 g/l methanol cannot be metabolized and accumulates.

In a prospective study on 78 patients admitted for alcohol detoxification, elevated SMC up to 78 mg/l were found, with a mean SMC of 29.4 mg/l.

No correlation was demonstrated between SMC and severity of the alcohol withdrawal syndrome.

Further clinical, forensic and biochemical aspects of methanol metabolism are discussed. PMID: 1776249


http://en.wikipedia.org/wiki/Methanol 2007.11.22

Health and safety

Methanol is toxic by two mechanisms. Firstly, methanol (whether it enters the body by ingestion, inhalation, or absorption through the skin) can be fatal due to its CNS depressant properties in the same manner as ethanol poisoning.

Secondly, it is toxic by its breakdown (toxication) by the enzyme alcohol dehydrogenase in the liver by forming formic acid and formaldehyde which cause permanent blindness by destruction of the optic nerve.[2]

Fetal tissue will not tolerate methanol.

Dangerous doses will build up if a person is regularly exposed to vapors or handles liquid without skin protection.

If methanol has been ingested, a doctor should be contacted immediately.

The usual fatal dose is 100 – 125 mL or grams = 4 fl oz.

[ Aspartame is 11 % methanol.

A 12-oz can of diet soda has about 200 mg aspartame, which quickly releases 22 mg methanol into the body.

Two liters of diet soda, 5.6 12 oz cans, can quickly put 123 mg methanol into the body.

This is just one thousandth of a lethal dose -- however, given 200 million users, if 1/1000 is using 2 L daily, and 1/10 of those are, at a guess, 10 times more vulnerable, that leaves 20,000 who could be accumulating various toxic products, getting troublesome symptoms, reacting to a variety of drugs, having more accidents, diseases, and life stress, and perhaps developing hypersensitivity -- just the sort of stories that arrive every week from new members of [email protected], now 1,050 current members since Jan., 1999. It's long overdue to do a thorough, competent study of these aspartame clients. ]

Toxic effects take hours to start, and effective antidotes can often prevent permanent damage.

This is treated using ethanol or fomepizole.[3]

Either of these drugs acts to slow down the action of alcohol dehydrogenase on methanol by means of competitive inhibition, so that it is excreted by the kidneys rather than being transformed into toxic metabolites.

The initial symptoms of methanol intoxication are those of central nervous system depression: headache, dizziness, nausea, lack of coordination, confusion, drowsiness, and with sufficiently large doses, unconsciousness and death.

The initial symptoms of methanol exposure are usually less severe than the symptoms resulting from the ingestion of a similar quantity of ethyl alcohol.

Once the initial symptoms have passed, a second set of symptoms arises 10–30 hours after the initial exposure to methanol: blurring or complete loss of vision, together with acidosis.

These symptoms result from the accumulation of toxic levels of formate in the bloodstream, and may progress to death by respiratory failure.


FORMIC ACID:

folic acid prevents neurotoxicity from formic acid, made by body from methanol impurity in alcohol drinks [ also 11 % of aspartame ], BM Bhushan, PL Carlen, DC Lehotay, AC Vandenbroucke, Y Adamchik, U. of Toronto, 2007 Dec., Alcoholism Cl. Exp. Res.: Murray 2007.11.27 http://rmforall.blogspot.com/2007_11_01_archive.htm Wednesday, November 27, 2007 http://groups.yahoo.com/group/aspartameNM/message/1495

[ See also: http://rmforall.blogspot.com/2007_11_01_archive.htm Wednesday, November 28, 2007 http://groups.yahoo.com/group/aspartameNM/message/1496 explosion in numbers of children with serious food allergies has bewildered experts and parents, Helen Francombe, The Australian 2007.11.17: role of formic acid from methanol in liquors and aspartame, Murray 2007.11.28 ]

http://www.faslink.org/toc2.htm

FASlink 2448 Hamilton Road, Bright's Grove, Ontario, Canada N0N 1C0 Phone: (519) 869-8026 E-mail: [email protected],

Fetal Alcohol Spectrum Disorders (FASD), Fetal Alcohol Syndrome (FAS), Fetal Alcohol Effects (FAE), Partial Fetal Alcohol Syndrome (pFAS), Alcohol Related Neurodevelopmental Disorders (ARND), Static Encephalopathy (alcohol exposed) (SE) and Alcohol Related Birth Defects (ARBD) are all names for a spectrum of disorders caused when a pregnant woman consumes alcohol

FASlink CD -- more than 170 MB of information.

While "officially" FASD is not a diagnosis but describes the broad range of disorders caused by prenatal alcohol exposure, the reality is that FASD IS the diagnosis and the other terms are sub-diagnoses describing the specific effects on a specific patient.

"St. Michael's Hospital, Fetal Alcohol Spectrum Disorder Clinic is pleased to support the work of FASlink. St. Michael's FASD Clinic views FASlink as an essential service for our clients. We are fortunate to partner with FASlink in our attempt to improve the lives of individuals and their families with FASD. Dr. Brenda Stade, St. Michael's FASD Clinic" St. Michael's Hospital is a teaching hospital affiliated with The University of Toronto.

FASD Overview

Invisible Disabilities -- An individual’s place, and success, in society is almost entirely determined by neurological functioning. A child with a brain injury is unable to meet the expectations of parents, family, peers, school, career and can endure a lifetime of failures. The largest cause of brain injury in children is prenatal exposure to alcohol. Often the neurological damage goes undiagnosed, but not unpunished.

There are strategies that can work to help the child with an FASD compensate for some difficulties. Early diagnosis and intensive intervention and tutoring can do wonders, but the need for a supportive structure is permanent.

Report on FASD -- Exposure Rates, Results of Prenatal Exposure to Alcohol, and Incidence Markers -- Bruce Ritchie - February 2, 2007 (PDF download 1.2 MB)

37% of babies have been exposed to multiple episodes of binge drinking (5+ drinks per session) during pregnancy.

An additional 42% have been multiply exposed to 1 to 4 drinks per session during pregnancy.

Prenatal alcohol exposure has been linked to more than 60 disease conditions, birth defects and disabilities.

Damage is a diverse continuum from mild intellectual and behavioural issues to profound disabilities or premature death.

Prenatal alcohol damage varies due to volume ingested, timing during pregnancy, peak blood alcohol levels, genetics and environmental factors.

For example, ethanol was found to interact with over 1000 genes and cell events, including cell signalling, transport and proliferation.

Serotonin suppression causes loss of neurons and glia, inducing excessive cell death during normal programmed death (apoptosis) or triggering apoptosis at inappropriate times leading to smaller or abnormal brain structures with fewer connections between brain cells, leading to fewer cells for dopamine production, leading to problems with addiction, memory, attention and problem solving, and more pronounced conditions such as schizophrenia.

Approximately 20% of Canadian school age children are receiving special education services, most for conditions of the types known to be caused by prenatal alcohol exposure.

As FASD is a diverse continuum, issues range from almost imperceptible to profound. It is somewhere in the middle that the issues attract the attention of parents, educators, medical and social work professionals, and eventually the justice system. Most of the issues that attract sufficient attention are behavioural and performance issues.

It is probable that about 15% of children are significantly enough affected by prenatal alcohol exposure to require special education. As they become adults, FASD does not disappear but the issues of youth translate into ongoing problems in family relationships, employment, mental health and justice conflicts. The cost to the individuals affected, their families and society are enormous and as a society, we cannot afford to ignore them.

To ignore the facts does not change the facts.

Most girls are 2 to 3 months pregnant before they find out. Maternal prenatal alcohol consumption even at low levels is adversely related to child behavior. The effect was observed at average exposure levels as low as 1 drink per week.


FASD Prevention

Folic acid should be added to all beverage alcohol.

Break the cycle. Properly fund addiction intervention and rehabilitation programs.

Identify women at risk of having children with FASD and intervene.

Meconium testing for Fatty Acid Ethyl Esters should be mandatory for every birth.

Intensive family and social service supports for FASD and recovering alcoholics.

Poverty is a result of, and breeds, substance abuse. Deal with it.

Alcohol Vendors

The beverage alcohol industry pays less than 1% of the total damages caused by their products. Increase taxes on beverage alcohol.

All tax revenue to be returned to support rehabilitation programs and victims of alcohol.

Remove all incentives for governments to promote alcohol.

End all government supports for beverage alcohol industry, including "wine and beer tourism".

End all alcohol advertising

Alcohol must be served with food.

Breathalyzers in all alcohol establishments

Ban alcohol sales incentives, contests, games.

Ban "Happy Hour" discounted promotions. They encourage binge drinking.

Public Education

Educate the public that addiction is a medical issue not a moral failure.

Educate children from a very young age about dangers of alcohol.

Have youth design anti-alcohol programs targeting youth.

The ONLY purpose of beverage alcohol is to make your brain take a hike.

Research

Better diagnostic tools for the full range of FASD damage.

True incidence and scaling of FASD damage.

Chemically turn-off addiction center in brain.

FASlink began online in 1995. FASlink's website contains more than 110,000 searchable FASD related documents and serves more than 400,000 visitors annually. The FASlink Discussion Forum shares 50 to 100 letters daily and compiles the papers and discussions into the FASlink Archives. Our membership is worldwide but most are in Canada and the USA, from the most remote locations to urban centers.

http://www.faslink.org/faslink.htm

The FASlink Discussion Forum is a free Internet maillist for individuals, families and professionals who deal with Fetal Alcohol Spectrum Disorders. FASlink provides support and information 24/7. FASlink has the largest archive of FASD information in the world. FASlink serves parents (birth, foster and adoptive), caregivers, adults with FASD, doctors, teachers, social workers, lawyers, students and government policy makers, etc. Bruce Ritchie is the Moderator.

To join FASlink, go to http://listserv.rivernet.net/mailman/listinfo/fas-link

Once you have subscribed, to send mail to the FASlink members, send it to: [email protected]

[email protected] sends email directly to the Moderator, Bruce Ritchie

References

  1. ↑ Oppermann JA, Muldoon E, Ranney RE (1973). "Metabolism of aspartame in monkeys". J. Nutr. 103 (10): 1454–9. PMID 4200872.
  2. ↑ Kim DJ, Yoon SJ, Lee HP, Choi BM, Go HJ (2003). "The effects of alcohol hangover on cognitive functions in healthy subjects". Int. J. Neurosci. 113 (4): 581–94. PMID 12856484. [e]
  3. ↑ Bendtsen P, Jones AW, Helander A (1998). "Urinary excretion of methanol and 5-hydroxytryptophol as biochemical markers of recent drinking in the hangover state". Alcohol Alcohol. 33 (4): 431–8. PMID 9719404. [e]
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