You might opt for diet soda instead of regular pop to save a few calories, but a new study by the National Institutes of Health indicates that you could be doing your mental health more harm than good in either case. The results suggest that there may be a link between diet soda and depression (and other diet beverages). The study, almost 20 years in the making, included nearly 264,000 adults from various parts of the United States.
The study could be very relevant to many Americans, as the Centers for Disease Control and Prevention reports that around 1 in 10 adults in the U.S. report suffering from depression. People between the age of 45 and 64 seem to be the most likely to have the condition. Other groups that have high depression rates include women, people whose highest education level is lower than high school, and those that have been divorced.
Major Increases in Depression Risk
The adult subjects in the study ranged in age from 50 to 71, and answered surveys regarding their soda consumption first in 1995 and 1996, and again in 2004, 2005 and 2006. During the second survey, researchers asked subjects whether they’d been diagnosed with depression since 2000. The researchers noticed increased risk of depression particularly among heavy soda drinkers.
Specifically, individuals who drank at least four cans of regular soda per day were 22% more at risk for depression than those who didn’t drink soda at all. Worse still, individuals who drank the same quantity of diet soda each day boosted their depression risk by 31% in comparison to non-soda drinkers.
The increased risk was most drastic for individuals who reported drinking at least four cans of zero-calorie fruit drinks daily: 51% greater in comparison to those who never imbibed these types of drinks, according to the researchers.
On the other hand diet soda and depression statistics didn’t seem to extend to coffee drinkers; coffee fanatics actually reduced their risk of depression in comparison to those who avoid the bean. The researchers noted that individuals who reported drinking at least four cups of coffee per day were 10% less at risk for depression than non-coffee drinkers.
Limitations of the Study
It’s important to note that the study found a link of association between heavy soda drinking and increased depression risk. This does not necessarily mean that you’ll become depressed by drinking soda, even in large quantities.
The researchers were careful to account for several factors that could influence depression risk, such as body mass index, exercise habits, smoking habits, age, education and gender. However, they failed to account for other important factors, such as whether subjects had a history of depression in their families and the prevalence of stressful events in their lives.
Experts have suggested that these final two factors are among the most important when it comes to predicting a diet soda and depression link. As people age, their lives become more prone to stressful events in the form of illnesses, career shifts and deaths of friends and family.
The American Beverage Association Weighs In
Regardless of these limitations, the study isn’t the first to find an association between heavy consumption of soda and other sweetened drinks and an increased risk of depression. Previous studies have also found that depression risk can increase regardless of whether the beverages contain calories.
However, some – particularly the American Beverage Association, which has a vested interest in making sure people buy soda and other sweetened drinks – are skeptical of the study’s findings. They said that current scientific evidence doesn’t suggest any connection between soda and depression risk, and that the National Institutes of Health study has yet to receive peer review and publication.
The Bottom Line
A recent study, though unpublished, suggests that drinking regular soda, diet soda and other sweetened beverages is associated with an increased risk of depression.
