Methanol is a natural alcohol, and when ingested in large amounts it can cause blindness and death. Smaller volumes can damage the brain. Most pro-aspartame sites compare the methanol volume with that found in tomato juice. The values are:
12oz tomato juice: .085g methanol
12oz diet drink: .024g methanol
'Hazardous workplace' studies found danger at a rate of 75 mg/kg of methanol. Governments often cap ingestion at 10 mg/kg a day for safety. For those of us used to pounds, let's go with -
75 kg = 165.35 lb
So if you were a 165 pound person, you could safely take in 75kg * 75mg = 5625mg of methanol, which is 5.6g. Most people only have one glass of tomato juice in the morning, then stop. Most soda drinkers drink soda all day long, quickly approaching dangerous levels.
Note that many people (including me) used to feel that tomatoes and other veggies had ethanol in them as well, which interacted with the methanol to help make it less dangerous. new research has shown that the amount of ethanol in a tomato is extremely tiny - at the level of 1/20th to 1/80th the amount of methanol. So it's probably not the ethanol in the tomato that helps make it healthier. It's the fact that you just drink one glass a day, not multiples.
Methanol in the eyes in particular turns into formate and can damage the eyes - hence the risk of blindness. From TheStraightDope: "In 1993 R. G. Walton et al reported that they had been compelled to halt a study of aspartame use by people with a history of depression because two participants suffered severe eye problems while the study was underway. One patient suffered a subconjunctival hemorrhage for the first time in her life while another required emergency surgery for a detached retina. The depressed patients also suffered other less severe symptoms." The eye problems might be coincidence, but this study was never repeated again to follow up on the symptoms ... one has to ask why not.
The average level of methanol in a human body has found to be between .6mg/l and 1mg/l depending on the person. Most industry-sponsored tests of aspartame didn't even start counting until 4mg/l, so a person could in essence have a 400% increase of methanol in their system without it being noticed at all. They then claim that "no change was detected". Also, some studies begin with a 12 hour fast. If a person fasts, then any methanol they ingest gets turned into formaldehyde - so that of course methanol wouldn't be detected. But formaldehyde is far worse!
When the FDA first approved aspartame it had the warning that aspartame should not be heated or used in cooking. This is because heating aspartame over 86F turns the methanol into formaldehyde. It is very easy to find many studies that discuss the damaging effects of formaldehyde on the human body.
So either you ingest the methanol and your body turns it into formaldehyde, or you heat up the aspartame (in your coffee or in cooking) and it turns into formaldehyde before you even consume it. What does formaldehyde do to you?
From the Blaylock 1998 paper: "formaldehyde formation from aspartame ingestion is very common and does indeed accumulate within the cell, reacting with cellular proteins (mostly enzymes) and DNA (both mitochondrial and nuclear). The fact that it accumulates with each dose, indicates grave consequences among those who consume diet drinks and foodstuffs on a daily basis."
Formaldehyde has been shown to cause headaches, immune system breakdown and nervous system breakdown, even at low doses.
Of the three components of aspartame - phenylaline, aspartic acid and methanol, methanol is only 10% of the makeup. But that 10% is just as dangerous as the other two.
Find out for yourself if you are sensitive to methanol and aspartame. If you normally are a big diet-soda drinker, or ingest other products with aspartame, cut them ALL out for 4 weeks. Instead, drink 8+ glasses of water a day and substitute in other low carb foods. See for yourself if you feel better at the end of the 4 weeks.
Aspartame Safety
Basics of Aspartame
Lisa Shea's Library of Low Carb Books
