Ask the experts: Aspartame and methanol

Q: "I read somewhere that aspartame breaks down into methanol in the body. Is this true, and is it bad for me?"

A: Aspartame produces methanol which breaks down into formaldehyde and formic acid in the body. Don't be alarmed by the names. These are normal by-products of metabolism which in turn break down to carbon-dioxide and water.

Aspartame is manufactured by joining two amino acids, aspartic acid and phenylalanine. These amino acids are found naturally in protein-containing foods. Aspartame is completely broken down in the digestive system into the two amino acids and methanol.

Methanol also occurs naturally in foods: it's found in fruit juices, fruits and vegetables. A soft drink containing aspartame provides one-fifth of the methanol as the same amount of tomato juice.