Effects of Aspartame

Aspartame is an artificial sweetener used in most diet drinks and foods labeled "sugar-free." The Food and Drug Administration (FDA) approved it for use in dry goods in 1981 and carbonated beverages in 1983. Aspartame contains 40 percent aspartic acid, 10 percent methanol and 50 percent phenylalanine. These acids and gas can have damaging effects on the body when consumed in large quantities, which makes aspartame a controversial sugar substitute.

Aspartic Acid

Aspartame contains 40 percent aspartate, an amino acid "excitotoxin" that can overstimulate and kill neural cells if there is too much in the brain. Long-term exposure to aspartate amino acid damage has been linked to chronic illnesses such as multiple sclerosis, epilepsy, Alzheimer's disease, Parkinson's disease, hypoglycemia and dementia. According to a study published in Impulse: The Premier Journal for Undergraduate Publications in the Neurosciences, "aspartic acid is not one of the essential amino acids. As a result of the excitatory effects of aspartic acid, the concentration in the brain must be controlled to prevent excess stimulation of the nerve cells." Although there is still much debate concerning the damage caused by excess aspartate as a result of aspartame consumption, the FDA recognizes several neurological symptoms, including headaches, migraines, seizures, dizziness, confusion, drowsiness and slurred speech.

Methanol

Made from methanol, aspartic acid and phenylalanine, 10 percent of aspartame releases as methanol. Methanol converts to formaldehyde and formate in the body. Formate causes blindness and acidosis, so consuming large quantities is toxic. The introduction of free methanol -- heated methanol -- causes the body to absorb methanol faster. According to the Impulse study, "methanol is poisonous at temperatures above 86-degrees Fahrenheit and therefore becomes toxic once aspartame is ingested." Although many juices also contain methanol, John McManamy explains that "the methanol in juices is chemically bound so it cannot be absorbed into the body whereas in aspartame it is in a free state where it can be absorbed." The FDA limit for safe methanol consumption is 7.8 milligrams per day, while a 1-liter beverage with aspartame contains about 56 milligrams of methanol. Symptoms of methanol poisoning include misty vision, blurred vision, retinal damage and blindness. Other symptoms include headaches, dizziness, nausea, gastrointestinal problems, vertigo, chills, numbness and neuritis.

Phenylalanine

Phenylalanine is an amino acid that affects brain chemistry. Some people are born with a condition called phenylketonuria (PKU). According to the University of Maryland Medical Center, "phenylketonuria (PKU) occurs in people who are missing an enzyme that the body needs to use phenylalanine. That causes high levels of phenylalanine to build up. If it is not treated before 3 weeks of age, PKU can cause severe, irreversible mental retardation." Even consumers without PKU are at risk for serious emotional disorders if they consume enough aspartame to create dangerous levels of phenylalanine. The levels of serotonin, a brain chemical that affects moods, may become dangerously low and lead to mood swings, depression violent rages and abnormal behavior. Such psychological and emotional disorders may need to be treated with therapy and mood-enhancing medication. According to a study by Dr. Ralph Walton, "There is evidence that the therapeutic effect of antidepressants can be blocked by parachlorophenylalanine -- a form of phenylalanine -- one of the major constituents of aspartame." This means that people undergoing treatment for depression should not consume aspartame.