Guest guest Posted April 14, 2002 Report Share Posted April 14, 2002 CancerAnswer, " mrsjoguest " <joguest@m...> wrote: JOURNAL OF APPLIED NUTRITION, VOLUME 36, NUMBER 1, 1984 REPORT ASPARTAME: METHANOL AND THE PUBLIC HEALTH DR. WOODROW C. MONTE ABSTRACT Aspartame (L-aspartyl-L-phenylalanine methyl ester), a new sweetener marketed under the trade name NutraSweet*, releases into the human bloodstream one molecule of methanol for each molecule of aspartame consumed. This new methanol source is being added to foods that have considerably reduced caloric content and, thus, may be consumed in large amounts. Generally, none of these foods could be considered dietary methanol sources prior to addition of aspartame. When diet sodas and soft drinks, sweetened with aspartame, are used to replace fluid loss during exercise and physical exertion in hot climates, the intake of methanol can exceed 250 mg/day or 32 times the Environmental Protection Agency's recommended limit of consumption for this cumulative toxin8. There is extreme variation in the human response to acute methanol poisoning, the lowest recorded lethal oral dose being 100 mg/kg with one individual surviving a dose over ninety times this level55. Humans, due perhaps to the loss of two enzymes during evolution, are more sensitive to methanol than any laboratory animal; even the monkey is not generally accepted as a suitable animal model42. There are no human or mammalian studies to evaluate the possible mutagenic, teratogenic, or carcinogenic effects of chronic administration of methyl alcohol55. The average intake of methanol from natural sources varies but limited data suggests an average intake of considerably less than 10 mg/day8. Alcoholics may average much more, with a potential range of between 0 and 600 mg/day, depending on the source and in some cases the quality of their beverages15. Ethanol, the classic antidote for methanol toxicity, is found in natural food sources of methanol at concentrations 5 to 500,000 times that of the toxin (Table 1). Ethanol inhibits metabolism of methanol and allows the body time for clearance of the toxin through the lungs and kidneys40,46. The question asked is whether uncontrolled consumption of this new sweetener might increase the methanol intake of certain individuals to a point beyond which our limited knowledge of acute and chronic human methanol toxicity can be extrapolated to predict safety. *NutraSweet is a trademark of G.D. Searle & Co. of the Food Science and Nutrition Laboratory Arizona State University Tempe, Arizona 85287 ASPARTAME Aspartame (L-aspartyl-L-phenylalanine methyl ester) has recently been approved as a sweetener for liquid carbonated beverages. It has had wide acceptance as an additive in many dry food applications after Food and drug Administration approval on July 24, 198148. The Food and Drug Administration, Dr. Richard Wurtman and myself have received well over a thousand written complaints relative to aspartame consumption. By far, the most numerous of these include dizziness, visual impairment, disorientation, ear buzzing, high SGOT, tunnel vision, loss of equilibrium, severe muscle aches, numbing of extremities, pancreatitis, episodes of high blood pressure, retinal hemorrhaging, menstrual flow changes, and depression. The validity of these complaints has yet to be scientifically evaluated. However, a thorough knowledge of just what makes this new sweetener stand apart from other nutritional substances might aid physicians in making dietary recommendations for their patients. Aspartame (NutraSweet)* is a small molecule made up of three components: Phenylalanine, aspartic acid, and methanol (wood alcohol)47. When digested, these components are released into the bloodstream48. Phenylalanine and aspartic acid are both amino acids which are found in natural proteins14, and under normal circumstances are beneficial, if not essential, for health. Proteins are complex molecules which contain many chemically bonded amino acids. it takes several enzymes to break these bonds and liberate the amino acids. This is a slow process and the amino acids area released gradually into the bloodstream40. The quaternary structure of protein also slows the digestion of these amino acids: the amino acids in the center of the protein molecule aren't released until the outer layers of amino acids on the surface have been swept away. This natural time release process saves the body form large numbers of any one of the 21 amino acids being released into the bloodstream at any one time. Aspartame requires the breaking of only two bonds for absorptioin47. This happens very quickly with the potential to raise component blood levels rapidly52. The methyl ester bond of phenylalanine is the first to cleave due to its susceptibility to pancreatic enzymes40. This is highly unusual; the methyl esters associated with pectin for instance are completely impervious to all human digestive enzymes6. AMINO ACID COMPONENTS Phenylalanine Phenylalanine is an essential amino acid, the daily consumption of which is required to maintain life. However, Dr. Richard J. Wurtman, Professor of Neuroendocrine Regulation at the Massachusetts Institute of Technology, presented data to the FDA demonstration that in humans the feeding of a carbohydrate with aspartame significantly enhances aspartame's positive effect on plasma and brain phenylalanine and tyrosine levels (48 Federal Register at 31379). There are sound scientific reasons to believe that increasing the brain levels of these large neutral amino acids could affect the synthesis of neurotransmitters and in turn affect bodily functions controlled by the autonomic nervous system61 (e.g., blood pressure). The proven ability of aspartame to inhibit the glucose-induced release of serotonin within the brain may also affect behaviors, such as satiety and sleep61. Aspartic acid Aspartic acid, is not an essential amino acid but is normally easily utilized for human metabolism. However, under conditions of excess absorption it has caused endocrine disorders in mammals with markedly elevated plasma levels of luteinizing hormone and testosterone in the rat52 and release of pituitary gonadotropins and prolactin in the rhesus monkey58. The amount of luteinizing hormone in the blood is a major determinant of menstrual cycling in the human female39. METHANOL Methanol (methyl alcohol, wood alcohol), a poisonous substance60, is added as a component during the manufacture of aspartame47. This methanol is subsequently released within hours of consumption51 after hydrolysis of the methyl group of the dipeptide by chymotrypsin in the small intestine40 as it occurs in soft drinks after decomposition of aspartame during storage or in other foods after being heated48. Regardless of whether the aspartame-derived methanol exists in food in its free form or still esterified to phenylalanine, 10% of the weight of aspartame intake of an individual will be absorbed by the bloodstream as methanol within hours after consumption51. Methanol has no therapeutic properties and is considered only as a toxicant20. The ingestion of two teaspoons is considered lethal in humans19. Methyl alcohol produces the Methyl alcohol syndrome, consistently, only in humans and no other test animal, including monkeys42,54. There is a clear difference between " toxicity " , which can be produced in every living thing, and the " toxic syndrome " 54. The greater toxicity of methanol to man is deeply rooted in the limited biochemical pathways available to humans for detoxification. The loss of uricase (EC 1.7.3.3.), formyl-tetrahydrofolate synthetase (EC 6.3.4.3.)42 and other enzymes18 during evolution sets man apart from all laboratory animals including the monkey42. There is no generally accepted animal model for methanol toxicity42,59. Humans suffer " toxic syndrome " 54 at a minimum lethal dose of < 1 gm/kg, much less than that of monkeys, 3-6 g/kg42,59. The minimum lethal dose of methanol in the rat, rabbit, and dog is 9.5, 7, and 8 g/kg, respectively43; ethyl alcohol is more toxic than methanol to these test animals43. No human or experimental mammalian studies have been found to evaluate the possible mutagenic, teratogenic or carcinogenic effects of methyl alcohol55, though a 3.5% chromosomal aberration rate in testicular tissues of grasshoppers was induced by an injection of methanol51. The United States Environmental Protection Agency in their Multimedia environmental Goads for Environmental Assessment recommends a minimum acute toxicity concentration of methanol in drinking water at 3.9 party per million, with a recommended limit of consumption below 7.8 mg/day8. This report clearly indicates that methanol: " is considered a cumulative poison due to the low rate of excretion once it is absorbed. In the body, methanol is oxidized to formaldehyde and formic acid; both of these metabolites are toxic. " 8 Role of Formaldehyde Recently the toxic role of formaldehyde (in methanol toxicity) has been questioned34. No skeptic can overlook the fact that, metabolically, formaldehyde must be formed as an intermediate to formic acid production54. Formaldehyde has a high reactivity which may be why it has not been found in humans or other primates during methanol poisioning59. The localized retinal production of formaldehyde from methanol is still thought to be principally responsible fro the optic papillitis and retinal edema always associated with the toxic syndrome in humans20. This is an intriguing issue since formaldehyde poisoning alone does not produce retinal damage20. If formaldehyde is produced form methanol and does have a reasonable half life within certain cells in the poisoned organism the chronic toxilogical ramifications could be grave. Formaldehyde is a know carcinogen57 producing squamous-cell carcinomas by inhalation exposure in experimental animals22. The available epidemiological studies do not provide adequate data for assessing the carcinogenicity of formaldehyde in man22,24,57. However, reaction of formaldehyde with deoxyribonucleic acid (DNA) has resulted in irreversible denaturation that could interfere with DNA replication and result in mutation37. Glycerol formal, a condensation product of glycerol and formaldehyde (which may be formed in vivo), is a potent teratogen causing an extremely high incidence of birth defects in laboratory animals52. even the staunchest critic of formaldehyde involvement in methanol toxicity admits: " It is not possible to completely eliminate formaldehyde as a toxic intermediate because formaldehyde could be formed slowly within cells and interfere with normal cellular function without ever obtaining levels that are detectable in body fluid or tissues. " 34 Acute Toxicity in man " Toxic Syndrome " A striking feature of methyl alcohol syndrome the asymptomatic interval (latent period) which usually lasts 12 to 18 hours after consumption. This is followed by a rapid and severe acidosis caused partially by the production of formic acid19. Insufficient formic acid is generated to account for the severity of metabolic acidosis produced and, therefore, other organic acids may be involved32. Patients may complain of lethargy, confusion, and impairment of articulation, all frequently encountered signs in moderate central nervous system (CNS) intoxications resulting from other toxic compounds20. Patients may also suffer leg cramps, back pain, severe headache, abdominal pain, labored breathing, vertigo and visual loss, the latter being a very important clue to making a diagnosis of methanol poisoning20. Other striking clinical features associated only with the oral administration of methanol are elevated serum amylase are the finding of pancreatitis or pancreatic necrosis on autopsy20,55. In fatal cases liver, kidneys and heart may show parenchymatous degeneration. the lungs show desquamation of epithelium, emphysema, edema, congestion and bronchial pneumonia12. Chronic Human Exposure This is the most important aspect of methanol toxicity to those who are interested in observing the effect of increased methanol consumption on a population. The data presented here were compiled by the Public Health Service. The individuals studied were working in methanol contaminated environments. It is interesting to note that the visual signs always associated with acute toxicity often do not surface under chronic conditions20. Many of the signs and symptoms of intoxication due to methanol ingestion are not specific to methyl alcohol. For example, headaches, ear buzzing, dizziness, nausea and unsteady gait (inebriation), gastrointestinal disturbances, weakness, vertigo, chills, memory lapses, numbness and shooting pains in the lower extremities hands and forearms, behavioral disturbances, and neuritis55. The most characteristic signs and symptoms of methyl alcohol poisoning in humans are the various visual disturbances which can occur without acidosis55 although they unfortunately do not always appear20. Some of these symptoms are the following: misty vision, progressive contraction of visual fields (vision tunneling), mist before the eyes, blurring of vision, and obscuration of vision20,55. ALCOHOLICS: CHRONIC METHANOL CONSUMPTION Alcoholics in general, but particularly those who consume large quantities of wine or fruit liqueur, would seem, from the available evidence, to be the only population thus far exposed to consistently high levels of methanol ingestion (Table 1). The high ethanol/methanol ratio of alcoholic beverages must have a very significant protective effect, though enzyme kinetics mandate some constant but low level of methanol metabolism. One could speculate that the delicate balance which maintains this defense might be jeopardized by the general nutritional neglect and specifically the folic acid deficiency21 associated with the meager food intake of some alcoholics. Alcoholics have a much higher incidence of cancer and other degenerative diseases, none of which can be attributed to ethanol alone56. The fascinating similarities linking unusual clinical features of methanol toxicity and alcoholism are worth noting. Neuritis: Chronic occupational exposure to methanol often produces human complaints of neuritis with paresthesia, numbing, prickling and shooting pains in the extremities4,55. Alcoholic polyneuropathy36 or multiple peripheral neuritis21 differs symptomatically from the methanol induced syndrome only in its first and often exclusive affinity for legs. The unpleasant sensations of intolerable pain associated with slight tactile stimulation36 is not an uncommon anecdotal consumer complaint following long term consumption of aspartame. In one such case reported to me, my interpretation of an electromyogram indicated the signs of denervation indicative of alcoholic polyneuropathy36. The individual's ischemic lactate pyruvate curve, before and after fasting, was flat. Less that six weeks after aspartame consumption ceased the major symptoms subsided and repetition of these tests produced normal responses, although the individual still experienced intermittent pain. Pancreatitis: Methanol is one of the few etiologic factors associated with acute pancreatic inflammation16,20. Microscopic findings of pancreatic necrosis on autopsy have been reported after acute oral methanol poisoning55. In fact, pancreatic injury probably accounts for almost universal violent epigastric pain17 and occasional elevated serum amylase levels55 which marks the end of the latent period. There is a generally accepted association between alcoholism and pancreatitis. Most patients, however, give a history of 5 to 10 years of heavy drinking before the onset of the first attack16. The fact that 40% of all cases of acute pancreatitis complaints are attributable to alcoholics21, however, must be taken into consideration to avoid artifactual association. Pancreatitis has been a complaint associated with aspartame consumption. Methanol and the Heart: A 21-year-old non-drinking male who had been exposed daily to the fine dust of aspartame at the packaging plant he had worked for over a year, was complaining of blurred vision, headaches, dizziness, and severe depression before his sudden death. An autopsy revealed (aside from the organ involvement one might expect from methanol toxicity) myocardial hypertrophy and dilatation with the myocardiopathy and left ventricle involvement reminiscent of alcoholic cardiomyopathy. Alcoholic cardiomyopathy however typically occurs in 30-55 year old men who have a history of alcohol intake in quantities comprising 30 to 50 percent of their daily caloric requirement over a 10 to 15 year period56. It has been suggested that alcohol is the etiologic factor in a least 50 percent of the cases of congestive cardiomyopathy56. The significantly lower hospitalization incidence for coronary disease among moderate drinkers than among nondrinkers and protection to coronary risk afforded the moderate drinker (less than two drinks a day) over the nondrinker56 seems contradictory. However, if we implicate methanol as the etiologic factor, then clearly the nondrinker is at a disadvantage with a much lower ethanol to methanol ration (Table 1) when consuming naturally occurring methanol in a diet otherwise equivalent to the drinkers. The chronic alcoholic for reasons already proposed might sacrifice this protection. As mentioned below, high temperature canning as developed late in the 19th century should increase significantly the methanol content of fruits and vegetables. The increased availability and consumption of these food products in various countries over the years may parallel better than most other dietary factors the increase in incidence of coronary disease in their populations. Cigarette smoke, a known coronary risk factor, contains four times as much methanol as formaldehyde and only traces of ethanol. ETHANOL AND FOLIC ACID The importance of ethanol as an antidote to methanol toxicity in humans is very well established in the literature46,55. The timely administration of ethanol is still considered a vital part of methanol poisoning management11,12,19,20,50. Ethanol slows the rate of methanol's conversion to formaldehyde and formate, allowing the body time to excrete methanol in the breath and urine. Inhibition is seen in vitro even when the concentration of ethyl alcohol was only 1/16th that of methanol62. The inhibitory effect is a linear function of the log of the ethyl alcohol concentration, with a 72% inhibition rate at only a 0.01 molar concentration of ethanol2,46. Oxidation of methanol, like that of ethanol, proceeds independently of the blood concentration, but a rate only one seventh20 to one fifth12 that of ethanol. Folacin may play an important role in the metabolism of methanol by catalyzing toe elimination of formic acid41. If this process proves to be a protective for humans as has been shown in other organisms50,38 it may account, in part for the tremendous variability of human responses to acute methanol toxicity. Folacin in a nutrient often found lacking in the normal human diet, particularly during pregnancy and lactation. METHANOL CONTENT OF ASPARTAME SWEETENED BEVERAGES An average aspartame-sweetened beverage would have a conservative aspartame content of a bout 555 mg/liter48,51, and therefore, a methanol equivalent of 56 mg/liter (56 ppm). For example, if a 25 kg child consumed on a warm day, after exercising, two-thirds of a two-liter bottle of soft drink sweetened with aspartame, that child would be consuming over 732 mg of aspartame (29 mg/kg). This alone exceeds what the Food and drug Administration considers the 99 - percentile daily consumption level of aspartame48. The child would also absorb over 70 mg of methanol from that soft drink. This is almost ten times the Environmental Protection Agency's recommended daily limit of consumption for methanol. To look at the issue from another perspective, the literature reveals death from consumption of the equivalent of 6 gm of methanol55,59. It would take 200 12 oz. cans of soda to yield the lethal equivalent of 6 gm of methanol According to FDA regulations, compounds added to foods that are found to cause some adverse health effect at a particular usage level are actually permitted in foods only at much lower levels. The FDA has established these requirements so that an adequate margin of safety exists to protect particularly sensitive people and heavy consumers of the chemical. Section 170.22 of Title 21 of the Code of Federal Regulations mandates that this margin of safety be 100-fold below the " highest no-effect " level has tragically not been determined for methanol8,11, but assuming very conservatively that the level is one tenth of the lethal dose, the FDA regulations should have limited consumption to approximately 2.4 ounces of aspartame sweetened soft drink per day, The FDA allows a lower safety margin only when " evidence is submitted which justifies use of a different safety factor. " (21.C.F.R. 170.22) No such evidence has been submitted to the FDA for methanol. Thus, not only have the FDA's requirements for acute toxicity not been met, but also, no demonstration of chronic safety has been made. The fact that methyl alcohol appears in other natural food products increases greatly the danger of chronic toxicity developing by adding another unnatural source of this dangerous cumulative toxin to the food system. NATURAL SOURCES OF METHANOL Methanol does appear in nature. To determine what impact the addition of a toxin will have on an environment it is very helpful to accurately determine the background levels of consumption. Fruit and vegetables contain pectin with variable methyl ester content. However, the human has no digestive enzymes for pectin6,25, particularly the pectin esterase required for its hydrolysis to methanol26. Fermentation in the gut may cause disappearance of pectin6 but the production of free methanol is not guaranteed by fermentation3. In fact, bacteria in the colon probably reduce methanol directly to formic acid or carbon dioxide6 (aspartame is completely absorbed before reaching the colon). Heating of pectins has been shown to cause virtually no demethoxylation: even temperatures of 120 C produced only traces of methanol3. Methanol evolved during cooking of high pectin foods7 has been accounted for in the volatile fraction during boiling and is quickly lost to the atmosphere49. Entrapment of these volatiles probably accounts for the elevation in methanol levels of certain fruit and vegetable products during canning31,33. In the recent denial by the food and drug Administration of my request for a public hearing on this issue13, the claim is made by them that methanol occurs in fruit juice at an average of 140 parts per million (a range of between 15-640 parts per million). This often used average originates from a informative table in a conference paper presented by Francot and Geoffroy15. The authors explain that the data presented in the table " may not " represent their work but " other authors " 15. There is no methodology given nor is the original source cited and only the identity of the lowest methanol source, grape juice (12 ppm), and the highest, black currant (680 ppm), are revealed. The other 22 samples used to generate this disarmingly high average are left completely to the imagination. The authors conclude their paper by insisting that " the content of methanol in fermented or non-fermented beverages should not be of concern to the fields of human physiology and public health. " They imply that wines " do not present any toxicity " due to the presence of certain natural protective substances15. When they present their original data relating to the methanol content of French wines (range 14-265 ppm) or when the methanol content of any alcoholic beverage is given, the ratio of methanol to ethanol is also presented. Of the wines they tested, the ratio associated with the highest methanol content (265 ppm) indicates over 262 times as much ethanol present as methanol. the scientific literature indicates that a fair estimate of methanol content of commonly consumed fruit juices is on the order of 40 parts per million (Table 1). Stegink, et al. points out that some neutral spirits contain as much as 1.5 grams/liter of methanol51, what is not mentioned is the fact if these spirits are at least 60 proof (30% ethanol) this still represents the presence of over 200 molecules of ethanol for every molecule of methanol that is digested. An exhaustive search of the present literature indicates that no testing of natural substances has ever shown methanol appearing alone; in every case ethanol is also present, usually, in much higher concentrations 15, 27, 28, 30, 31, 35, 44, 45. Fresh orange juices can have very little methanol (0.8 mg/liter), and have a concomitant ethyl alcohol content of 380 mg/liter28. Long term storage in cans has a tendency to cause an increase in these levels, but even after three years of storage, testing has revealed only 62 mg/liter of methanol, with an ethanol content of 484 mg/liter. This is a ratio of almost eight times ethanol/methanol l28. Testing done recently in Spain showed orange juice with 33 mg/liter methanol and 651 mg/liter ethanol (20/1 ratio)45. The range for grapefruit juices are similar, ranging form 0.2 mg methanol/liter 27 to 43 mg methanol/liter 27. The lowest ratio or any food item was found in canned grapefruit sections with 50-70 mg/liter methanol and 200-400 mg/liter ethanol 27, thus averaging six molecules ethanol for every molecule of methanol. This high ethanol to methanol ratio, even a these low ethanol concentrations, may have some protective effect. As stated previously, ethanol slows the rate of methanol's conversion to formaldehyde and formate allowing the body time to excrete methanol in the breath and urine. Inhibition is seen in vitro even when the concentration of ethyl alcohol was only 1/16th that of methanol62. The inhibitory effect is a linear function of the log of the ethyl alcohol concentration, with a 72% inhibition rate at only a 0.01 molar concentration of ethanol. Therefore if a liter of a high methanol content orange juice is consumed, with 33 mg/liter of methanol and a 20/1 ratio of ethanol/methanol, only one molecule of methanol in 180 will be metabolized into dangerous metabolites until the majority of the ethanol has been cleared from the bloodstream. If a similar amount of methanol equivalent from aspartame were consumed, there would be no competition46. Another factor reducing the potential danger associated with methanol from natural juices is that they have an average caloric density of 500 Kcal/liter and high osmolarity which places very definite limits to their consumption level and rate. [begin webmaster note] *following numeric colums* First and last columns below have complete names. CAL/LIT = Methanol (MG) Caloric Densidty (calorie/liter) RATIO/1000c = Ration consumed per 1000 calories * = Methano (MG) Ethanol (wt.) Methanol (wt.) [end note] TABLE 1 AVAILABLE METHANOL IN VARIOUS BEVERAGES Juices METHANOL CAL/ RATIO * Consumption mg/liter LIT /1000c per day *Orange, fresh(28) 1 470 2 475 1 *Orange, fresh(45) 33 470 70 20 6 mg *Orange, fresh(31) 34 470 72 16 6 mg *Orange, canned(28) 31 470 66 15 6 mg *Grapefruit, fresh(27) 1 400 1 2000 1 mg *Grapefruit(31) 43 400 108 5 7 mg Grapefruit, Canned(31) 27 400 68 9 5 mg Grape(15) 12 660 18 -- -- Alcoholic Beverages Beer (4.5%) 0 400 -- -- -- Grain Alcoho(l55) 1 2950 1 500000 -- Bourbon, 100 proof 55 2950 19 9090 -- Rum, 80 proof(15) 73 2300 32 5000 -- Wines (French)(15) White 32 800 44 2500 -- Rose 78 800 98 1000 -- Red 128 800 160 667 -- Pear 188 1370 137 250 -- Cherry 276 1370 201 294 -- Wines (American)(30) Low 50 800 62 2500 -- High 325 800 406 385 -- Aspartame Sweetened Beverages(48) 2 and 5 liters Uncarbonated Drinks(48) 55 8 6875 0 110 mg 275 mg Cola (Carbonated)(48) 56 8 7000 0 112 mg 280 mg Orange (Carbonated)(48) 91 8 11375 0 182 mg 455 mg Aspartame, pure 25000 *17.6% of U.S. Population consume an average of 185.5 gm of Orange juice a day1 *1.1% of the U.S. Population consumes an average of 173.9 gm of Grapefruit Juice a day1 Data obtained in a Department of Agriculture survey of the food intake of a statistically sampled group of over 17,000 consumers nationwide1, indicate that the 17.6% of the population that consume orange juice daily take in an average of 185.5 gm of that juice. these statistics indicated that 1.1% of the population consume an average of 173.9 gm of grapefruit juice while only 1.8% drink approximately 201 gm of tomato juice daily. Table 1 shows that under normal conditions these individuals would only be expected to consume between 1 and 7 mg of methanol a day from the sources. Even if an individual consumed two juices in the same day or a more exotic juice such as black currant, there would still be some protection afforded by the ethanol present in these natural juices. Consumption of aspartame sweetened drinks at levels commonly used to replace lost fluid during exercise yields methanol intake between 15 and 100 times these normal intakes (Table 1). This is comparable to that of " winos " but without the metabolic reprieve afforded by ethanol. An alcoholic consuming 1500 calories a day from alcoholic sources alone my consume between 0 and 600 mg of methanol each day depending on his choice of beverages (Table 1). The consumption of aspartame sweetened soft drinks or other beverages is not limited by either calories or osmolarity, and can equal the daily water loss of an individual (which for active people in a state like Arizona can exceed 5 liters). The resultant daily methanol intake might then rise to unprecedented levels. Methanol is a cumulative toxin8 and for some clinical manifestations it may be a human-specific toxin. CONCLUSION Simply because methanol is found " naturally " in foods, we can not dismiss the need for carefully documented safety testing in appropriate animal models before allowing a dramatic increase in its consumption. We know nothing of the mutagenic, teratogenic or carcinogenic effect of methyl alcohol on man or mammal55,59. Yet, if predictions are correct5 it won't be long before an additional 2,000,000 pounds of it will be added to the food supply yearly53. Must this, then, constitute our test of its safety? References 1.Agricultural Research Service, U.S. Department of Agriculture, Portion sizes and days intakes of selected foods, ARS-NE-67 (1975). 2.Bartlett, G.R., Inhibition of Methanol Oxidation by Ethanol in the Rat.Am. J. Physiol., 163:619-621 (1950). 3.Braverman, J.B.S. and Lifshitz, A., Pectin Hydrolysis in Certain Fruits During Alcoholic Fermentation. Food Tech., 356-358, July, (1957). 4.Browning, E., Toxicity and Metabolism of Industrial Solvents, New York: Elsevier Publishing Company, (1965). 5.Bylinsky, G., The Battle for America's Sweet Tooth. Fortune, 28-32, July (1982). 6.Campbell, L.A., Palmer G.H., Pectin in Topics in Dietary Fiber Research. Edited spiller, G.A. and Amen, R.J. Plenum Press, NY (1978). 7.Casey,J.C., Self, R. and Swain, T., Origin of Methanol and Dimethyl Sulphide from Cooked Foods. Nature, 200:885 (1963). 8.Cleland, J.G. and Kingsbury, G.L., Multimedia Environmental Goals For Environmental Assessment. U.S. Environmental Protection Agency: EPA-600/7-77-136b, E-28, November 1977. 9.Code of Federal Regulations 21 subpart C, Section 173.250. 10.Cooper, J.R. and Kini, M.M., Biochemical Aspects of Methanol Poisoning. Biochem. Pharmacol., 11:405-416 (1962). 11.DeCostro, F., et al., Clinical Toxicology Manual. St. Louis, Missouri: The Catholic Hospital Association, (1978). 12.Dreisback, R.H., Handbook of Poisoning. 11th ed. Los Altos, CA: Lange Medical Publication (1983). 13.Food and Drug Administration, Denial of Requests for Hearing. Docket Nos. 75F-0355, 4160-01 (1984). 14.Food and Nutrition Board: Recommended Dietary Allowances, 9th Ed., Washington DC, National Research Council, National Academy of Science, (1980). 15.Francot, P. and Geoffroy, P., LeMethanol dans les jus de fruits, les boissons, fermentees, les alcools et spiritueux. Rev. Ferment. Inc. Aliment., 11:279-287 (1956). 16.Geokas, Michael C., Ethanol and the Pancreas. Med. Clin. N. Am., 68(1):57-75 (1984). 17.Gilman, A., Goodman & Gilman's The Pharmacological Basis of Therapeutics. 6th ed. Alfred Gilman, et al., eds., New York: Macmillian Publishing Co. Inc. (1980). 18.Goodman, J.I. and Tephly, T.R., Peroxidative Oxidation of Methanol in Human Liver: The Role of Hepatic Microbody and Soluble Oxidases. Res. Commun. Chem. Pathol. Pharm., 1(4):441-450 (1970). 19.Gosselin, R.E. Clinical Toxicology of Commercial Products. 4th ed. Gosselin, R.E., et al., eds., Baltimore, Maryland: Williams & Wilkins (1981). 20.Hadden, L., et al., Clinical Management of Poisoning. Philadelphia, Pennsylvania: W. B. Saunders Company (1983). 21.Holvey, D.N., the Merck Manual. 12th ed Rahway, New Jersey: Merck and Company (1972). 22.International Agency for Research on Cancer. IARC Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Supplement 4. Lyon, France: IARC, 1982. 23.International Agency for Research on Cancer. IARC Monographs on the Evaluation of the Carcinogenic Risk of Chemical to Man. Vol. 7 Lyon, France: IARC, 1974, pp. 45-52. 24.International Agency for research on Cancer. IARC Monographs on the Evaluatio of the Carcinogenic Risk of Chemicals to Humans. Vol. 29 Lyon, France: IARC, 1982, pp. 345-89. 25.Kertesz, Z.I. The Pectic Substances. Interscience Publishers, Inc., New York, (1951). 26.Ketesz, Z.I. The Pectic Enzymes, J. Nutr., 20:289-296 (1940). 27.Kirchner, J.G., Miller, J.M., Rice, R.G., Keller, G.J., and Fox, M.M., Volatile Water-Soluble Constituents of Grapefruit Juic. J. Agric. Food Chem., 1(7):510-518 (1953). 28.Kircher, J.G. and Miller, J.M., Volatile Water-Soluble and Oil Constituents of Valecia Orange Juice. Agric. Food Chem., 5(4):283-291 (1957). 29.Leaf, G. and Zatman, L.J., A Study of the Conditions Under Which Methanol May Exert a Toxic Hazard in Industry. Brit. J. Ind. Med., 9:1931 (1952). 30.Lee, C.Y., Acree, T.E. and Butts, R.M., Determination of Methyl Alcohol in Wine by Gas Chromatography. Anal. Chem., 47(4):747-748 (1975). 31.Lund, E.D., Kirkland, C.L. and Shaw, P.E., Methanol, Ethanol, and Acetaldehyde Contents of Citrus Products. J. Agric. Food Chem., 29:361-366 (1981). 32.McMartin, K.E., Makar, A.B., Martin-Amat, G., Palese, M. and Tehly, T.R. Methanol Poisoning. I. The Role of Formic Acid in the Development of Metabolic Acidosis in theMonkey and the Reversal by 4- Methylpyrazole. Biochem. Med., 13:310-333 (1975). 33.McMartin, K.E., Martin-Amat, G., Makar, A.B. and Tephly, T.R. Methanol Poisoning. V. Role of Formate Metabolism in the Monkey. J. Pharmacol. Exp. Ther., 201(3):564-572 (1977). 34.McMartin, K.E., Martin-Amat, G., Noker, P.E. and Tephly, T.R., Lack of a Role for Formaldehyde in Methanol Poisoning in the Monkey. Biochem. Pharm., 28:645-649 (1978). 35.Moshonas, M.G. and Lund, E.D., A Gas Chromatographic Procedure for Analysis of Aqueous Orange Essence. J. Food Sci., 36:105-106 (1971). 36.Nakada, T., and Knight, R.T., Alcohol and the Central Nervous System. Med. Clin. N. Am., 68(1) " 121-131 (1984). 37.Newell, G.W., Overview of Formaldehyde. Formaldehyde Toxicity. J.E. Gibson Ed., Hemisphere Publishing Corporation, pp. 3-12 (1983). 38.Noker, P.E. and Tephly, T.R., the Role of Folates in Methanol Toxicity. Adv. Exp. Med. Biol., 132:305 (1980). 39.Olney, J.W., Cicero, T.J., Mayer, E.R., and deGubareft, T. Acute glutamate-induced elevations in serum testosterone and lenteinizing hormone. Brain Res., 112:420-424 (1976). 40.Oppermann, J.A., Muldoon, E. and Ranney, R.E., Metabolism of Aspartame in Monkey. J. Nutr., 103:1454-1459 (1973). 41.Rietbrock, N., Herken, W. and Abshagen, V. Folate Catalyzed Elimination of Formic Acid from Methanol Poisoning. Biochem. Pharmacol, 20:2613 (1971). 42.Roe, O., Species Differences in Methanol Poisoning. CRC Critical Rev. in Tox., pp. 275-286, October, (1982). 43.Roe, O., The Metabolism and Toxicity of Methanol. Pharmacol. Rev., 7:399 (1955). 44.Roe, B. and Bruemmer, J.H., Enzyme-Mediated Aldeyhde Change in Orange Juice. J. Agr. Food Chem., 22-285-288 (1974). 45.Sauri, E., Nadal, I., Alberola, J., Sendra, J.M., Izquierdo, L. (Inst. Agroquim. Tecnol. Alimentos, CSIC, Valencia, Spain 10). Rev. Agroquim Tecnol. Aliment. 1981, 21 (2), 276-80 (Span). 46.Seale Aspartame Petition. Document No.: MRC-751-0022 (E-92). Methanol Metabolism in the Monkey, Mol. Pharmacol., 4:471-483, (1963). 47.Searle Food Resources, Inc. Sources and Metabolism of Aspartame and Representative Sweeteners. (1981). 48.Searle Research and Development. Aspartame for use as a Sweetener in Carbonated Beverages. Petition submitted to the United States Food and Drug Administration – FAP 2A3661. 49.Self, R., Casey, J.C., Swain, T., The Low-Boiling Volatiles of Cooked Foods. Chem. And Indust., 863-864 (1963). 50.Smith, E.N. and Taylor, R.T., Acute Toxicity of Methanol in the Folate-Deficient Acatalasemic Mouse. Toxicology, 25:271-287 (1982). 51.Staples, R.E. Teratogenicity of Formaldehyde. Formaldehyde Toxicity. J.E. Gibson, Ed., Hemisphere Publishing Company pp 51-60 (1983). 52.Stegink, L.D., Brummel, M.C., McMartin, K., Martin-Amat, G., Filer, L.J., Jr., Baker, G.L. and Tephly, T.R., Blood Methanol Concentrations in Normal Adult Subjects Administered Abuse Doses of Aspartame. J. Toxicol. Environ. Health, 7:281-290 (1981). 53.Strittmatter, P. and Ball, E.G., Formaldehyde Dehydrogenase, A Glutathione-Dependent Enzzzyme System. J. Biol. Chem., 213:445-461 (1955). 54.Tephly, T.R., Watkins, W.D. and Goodman, J.I., The Biochemical Toxicology of Methanol. Essays Toxicol., 5:149-177 (1974). 55.U.S. Department of Health, Education, and Welfare. Occupational Exposure to Methyl Alcohol, HEW Pub. No. (NIOSH) 76-148, March (1976). 56.U.S. Department of Health and Human Services. Alcohol and Health. Fourth Special Report to the U.S. Congress. DeLuca, J.R., ed. January 1981. 57.U.S. Department of Health and Human Services. Third Annual Report on Carcinogens. PB: 33-135855, September, 1983. 58. Wilson, R.C., and Knobil, E. Acute effects of N-methyl-DL- aspartate on the release of pituitary gonadotropins and polactin in the adult female rhesus monkey. Brain Res., 248:177-179 (1982). 59. Wimer, W.W., Russell, J.A. and Kappplan, H.L., Alcohols Toxicology. Park Ridge New Jersey, Noyes Data Corporation (1983). 60.Windholz, M., Merck Index. 9th ed Rahway, New Jersey: Merck & Company Inc. (1976). 61.Wurtman, R.J. Neurochemical Changes Following High-Dose Aspartame with Dietary Carbohydrates. New Eng. J. Med., 309(7):429-30 (1983). 62.Zatmann, L.J., The Effect of Ethanol on the Metabolism of Methanol in Man. Biochem. J., 40:67-68 (1946). ************************************************************* ( " 'Richard T. Murray' " <rmforall@e...> 3-15-99) Rich Murray Room For All 1943 Otowi Drive Santa Fe, NM 87505 505-986-9103 505-920-6130 cellular VoiceStream Keep up the good work. Send me your address and I will mail you a copy of my original article. You have my permission to post it anywhere you wish. (signed) Woodrow C. Monte Ph.D. Professor of Food Science 6411 South River Drive #61 Tempe, Arizona 85283-3337 United States of America Phone/Fax 001 602-965-6938 woody.monte@a... **************************************************************** [Notes by Rich Murray rmforall@e... 3.17.99: PubMed lists 14 papers and letters by " Monte WC " and various partners, from 1977 to 1994, but not this one. Go figure! http://www.ncbi.nlm.nih.gov/PubMed/ Two L of diet soda contains 1110 mg aspartame, putting 112 mg methanol into the body. This is 5.6 12-oz cans at 197 mg aspartame per can, giving 20 mg methanol each can. The Environmental Protection Agency limit in water for methanol, a cumulative poison, is 7.8 mg/day .] --- End forwarded message --- Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You are posting as a guest. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.