[1] [2] [3] [4] The negative physical health effects of soda are well-documented: Sugary soft drinks increase the risk of obesity, type 2 diabetes , and heart disease, and have even been linked to cancer. [5] Now, a new study suggests that drinking soda frequently may fuel the growth of gut bacteria linked with depression risk. Women who drank the most soda had a 17 percent higher risk of depression compared with women who didn’t regularly drink it. Dr. Naidoo, who is a member of the American Psychiatric Association, points out that while an unhealthy diet may affect mental health, poor mental health can also lead to bad food choices. [2] “Even moderate consumption [of sugary drinks] can be risky, especially if it replaces healthier options,” says Tung.