Phenylalanine also easily enters the brain, where it is transformed into neurotransmitters that can further interfere with normal brain function. This is a likely reason why aspartame lowers the threshold for seizures, mood disorders, and other nervous system problems. This altered brain chemistry may also be responsible for the addictive nature of aspartame. The remaining component, which makes up 10 percent of aspartame, may be the most dangerous part. It is a methyl ester that breaks down after ingestion into methanol, a nervous system toxin also known as free methyl alcohol or wood alcohol.
Methanol is extremely harmful to the optic nerve.
Please take the warnings in this article very seriously. Although some people are much more sensitive to aspartame's adverse effects than others, damage is likely cumulative. Aspartame is particularly harmful to children and the developing fetus. Don't trade one bad habit for another by switching to sugar-laden drinks and sweets. Avoid most bottled or canned sodas, teas and juices altogether.