The question becomes, ‘Are diet drinks better than those containing sugar?’ The short answer is, ‘Not likely.’ Diet drinks contain artificial sweeteners (to compensate for not having real sugar), such as aspertame. Excitotoxins can cause gradual damage to your brain. Research presented at a conference of the American Stroke Association indicates that drinking diet soda daily is linked to a significantly higher risk of vascular events that correlate with vascular dementia. Other research published in the journal Natural Chemical Biology reported that phenylalanine, an amino acid found in aspartame, can form the toxic amyloid fibrils that are the hallmark of brain diseases such as Alzheimer’s and Parkinson’s. Drinking pure water continues to be your best bet.