The next time you pop open a can of diet soda, pause for a moment to consider what exactly you’re drinking. As the aspartame gets broken down in your digestive tract, a metabolic by-product called DKP appears. According to Dr. Blaylock, when your stomach processes DKP, it produces a compound very similar to N-nitrosourea, a powerful brain tumor-causing chemical. In addition, aspartame contains methanol, which the body breaks down into formic acid and formaldehyde. Formaldehyde is one of the main substances pumped into a dead body during the embalming process.