By now, you have seen any number of articles telling you that drinking sweetened beverages is bad for your physical health, these drinks having been linked to surges in the incidence of obesity, diabetes, osteoporosis, metabolic syndrome, fatty liver disease, and heart attacks. But did you know that drinking sodas and other sweetened drinks could be bad for your mental health as well?
Large-scale long-term study finds link to depression
That is the finding of a study to be presented at the American Academy of Neurology’s annual meeting in San Diego in March 2013, based on research performed by Honglei Chen, M.D. and Ph.D., and a member of the American Academy of Neurology. In Dr. Chen’s study, 263,925 people who were between the ages of 50 and 71 when the research began, were studied for ten years, measuring their consumption of soda, tea, fruit punch, and coffee. All of the sodas, fruit punches, and iced teas measured were sweetened, but some were diet drinks, meaning that the sweeteners used contained no calories.
At the ten-year mark, the study subjects were polled and asked whether they had been diagnosed with depression, and the researchers found that depression had been diagnosed in 11,311 of the study participants. Correlating the depression diagnoses (or lack thereof) with their beverage intake data, the researchers found that people who drank four cans or cups of soda per day were 30 percent more likely to be diagnosed with depression than those who drank no soda at all. The subjects who drank four or more cans of fruit punch were 38 percent more likely to develop depression than those who did not drink sweetened drinks. These risks were even higher for those who drank diet sodas and fruit punches than for those who drank regular (sugar-sweetened) sodas, fruit punch, or iced tea.
Coffee found to be protective against depression
Interestingly, people who drank four cups of coffee per day were 10 percent less likely to develop depression than people who drank no coffee. This finding is in accord with a 2011 study published in the Archives of Internal Medicine that showed an association between caffeinated coffee consumption and a decreased risk of depression. When asked to speculate as to why coffee created a reduced risk for depression, Chen said, "Coffee contains large amounts of caffeine, which is a well-known brain stimulant," which may enable it to have an effect on people’s moods and their overall feelings of well-being.
Although these findings look bad for sodas and sweetened drinks, it is important to remember that the study only found an association, and was not able to determine whether sodas and fruit drinks actually caused the increased rates of depression. The researchers did take into account factors that could affect the results, such as age, sex, education, smoking status, physical activity, body mass index, and energy intake, but it is possible that other unmeasured factors such as having a family history of depression or having experienced stressful life events could explain the increased depression rates.
However, describing his overall findings and their potential impact, Chen says, "Our research suggests that cutting out or down on sweetened diet drinks or replacing them with unsweetened coffee may naturally help lower your depression risk."