Virtually all of the marketing material emphasizes the fact that aspartame is natural and made of two amino acids, the building blocks of protein. But, like many deceptions, this is only partially true. While there are two amino acids that comprise 90% of aspartame, aspartic acid and phenylalanine, they are held together in a methyl ester bond that comprises 10% of the molecule.
The methanol is released from the aspartame within hours of consumption after hydrolysis of the methyl group of the dipeptide by chymotrypsin in the small intestine. Once this methyl ester bond is broken it liberates free methyl alcohol or methanol, which is commonly called wood alcohol. The problem with methanol is that it passes into your blood-brain barrier and is converted into formaldehyde, which causes the damage. You may recognize formaldehyde as embalming fluid.
Interestingly, methanol is only toxic in humans. All other animals are able to detoxify it before it causes damage.
Methanol is a toxin that destroys the myelin tissue in your body, which is the insulating material around your nerves that allows nerve signals to travel properly. Once injured, one can have what are called demyelinating symptoms that are commonly seen in diseases like MS and also migraines that can include bizarre and inconsistent visual field disruptions.
My sister that helped me start my practice in 1985 is actually one of the people that develops these symptoms when exposed to aspartame. In the late ‘80s I helped to diagnose her with this sensitivity and she has avoided it for over 25 years.
Why is Methanol So Toxic?
Methanol breaks down into formic acid and formaldehyde in your body. Many experts believe formic acid is the problem but the real problem is the formaldehyde, which is a deadly neurotoxin and carcinogen. An EPA assessment of methanol states 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.”
They recommend a limit of consumption of 7.8 mg/day. But according to Woodrow Monte, Ph.D, R.D., director of the Food Science and Nutrition Laboratory at Arizona State University:
“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 toxin.”
Further, he states that due to the lack of a couple of key enzymes, humans are many times more sensitive to the toxic effects of methanol than animals. Therefore, tests of aspartame or methanol on animals do not accurately reflect the danger for humans.
“There are no human or mammalian studies to evaluate the possible mutagenic, teratogenic, or carcinogenic effects of chronic administration of methyl alcohol,” he said.
Symptoms from methanol poisoning are many, and include headaches, ear buzzing, dizziness, nausea, gastrointestinal disturbances, weakness, vertigo, chills, memory lapses, numbness and shooting pains in the extremities, behavioral disturbances, and neuritis. The most well known problems from methanol poisoning are vision problems including misty vision, progressive contraction of visual fields, blurring of vision, obscuration of vision, retinal damage, and blindness. Formaldehyde is a known carcinogen that causes retinal damage, interferes with DNA replication and may cause birth defects. The researchers in the featured study then reasoned that the aspartame-induced methanol exposure was likely possible for oxidative stress in the brain.