Aspartame

The National Institutes of Health–AARP Diet and Health Study, the largest-ever prospective study conducted on diet and health, followed hundreds of thousands of Americans for a decade and found that frequent consumption of sweetened beverages may increase the risk of depression among older adults. Indeed, adding sugar to coffee may negate many of its positive effects on mood, and adding the artificial sweetener aspartame (found in Equal and NutraSweet) or saccharine (in Sweet’n Low) was also associated with an increased risk of depression.

The controversy surrounding the neurological effects of aspartame began in the 1980s. At first, concern was limited to those with preexisting mental illness. An early study at Case Western Reserve University was halted prematurely for safety reasons because subjects with a history of depression appeared to be experiencing such severe reactions to the sweetener. The researchers concluded that “individuals with mood disorders are particularly sensitive to this artificial sweetener and its use in this population should be discouraged.”

Only recently were the neurobehavioral effects of aspartame investigated in a population free from mental illness. Healthy individuals were split into two groups—half were given a higher dose of aspartame (the equivalent of about three liters of Diet Coke’s worth) and the other half received a lower dose (a single liter of Diet Coke’s worth). Then the groups switched. After only eight days on the higher-aspartame dose, participants exhibited more depression and irritability, and performed worse on certain brain function tests. So not only may aspartame cause adverse mental effects in sensitive populations but it may also harm the general public at sufficient doses.

Avoiding diet soda and those pastel paper packets seems easy enough, but artificial sweeteners are also present in more than six thousand products, including breath mints, cereals, chewing gums, jams and jellies, juice drinks, puddings, and even nutritional bars and yogurts.

For substantiation of any statements of fact from the peer-reviewed medical literature, please see the associated videos below.