When it comes to drinking soda, diet is better in terms of sugar and calorie content when compared to regular soda. Diet soda, however, comes with its own set of risks, and it's partly the artificial sweeteners that make the beverage a poor dietary choice. There is a link between drinking diet soda and depression, for example. That doesn't mean you're destined for depression if you enjoy diet soda, but the connection is worth considering as you make beverage choices in the future.
A study conducted by the American Academy of Neurology that involved 263,925 adults between the ages of 50 and 71 discovered a link between drinking diet soda and depression. The participants recorded their intake of drinks such as soda, coffee, tea and fruit punch between 1995 and 1996. Ten years later, the participants told researchers whether they had been diagnosed with depression since the year 2000, and 11,311 people stated that they had been so diagnosed. Participants who drank more than four cans of soda per day were 30 percent more likely to be diagnosed with depression compared to people who didn't drink any soda, and the risk was greater for participants who drank diet soda.
Artificial Sweeteners Partly to Blame
People with depression tend to have lower brain-derived neurotrophic factor, or BDNF, levels, according to a 2013 article published in the "Indian Journal of Psychiatry." Diet plays a role in your BDNF levels, and people who eat large amounts of fat or refined sugars tend to have lower levels. This suggests a potential link between diet soda, or any soda for that matter, and depression. Much of the research on the link between BDNF and diet, however, has been conducted with animals, which means that additional research is necessary to determine if avoiding diet soda can reduce the risk of depression.
Diet Soda and Type-2 Diabetes
Daily consumption of diet soda raises the risk of type-2 diabetes, according to a 2009 article published in "Diabetes Care." Type-2 diabetes, in turn, raises the risk of depression. The American Diabetes Association theorizes that the stress of managing diabetes, feelings of loss of control over blood sugar and other complications, such as nerve damage, all contribute to depression in patients with type-2 diabetes. Depressed patients with diabetes are at a higher risk for dementia, as well, according to a 2012 study published in "Archives of General Psychiatry."
The Weight Gain Link
It seems counterintuitive, but drinking diet soda can actually lead to weight gain even though the beverage itself is calorie-free. Research conducted by Susan E. Swithers, a professor at Purdue University, suggests that drinking diet sodas leads to weight gain, partly because of overeating. In other words, a person drinking diet soda might feel so virtuous about drinking a zero-calorie beverage that he feels like he can eat more than he normally would. This is an important link because being overweight can increase the risk of depression. Depression also raises the risk of obesity, which increases the chances of chronic health problems such as heart disease.