Diet drinks, once billed as a healthy alternative to regular soft drinks, have long been assailed for their misleading name. Now, researchers think that diet drinks, and in particular diet sodas, may lead to a higher risk of depression.
The study, presented this week at the American Academy of Neurology’s 65th Annual Meeting in San Diego, demonstrated a potential link between sweetened drinks, already known to be damaging, and an increased risk of depression.
Honglei Chen, MD, PhD, with the National Institutes of Health in Research Triangle Park in North Carolina, and team took 263,925 people between the ages of 50 and 71 and then, between 1995 to 1996, assessed their consumption of drinks such as soda, tea, fruit punch and coffee.
A decade on, the researchers returned to assess whether participants had been diagnosed with depression since the year 2000. A total of 11,311 such diagnoses were made.
While the causes of depression are many, the researchers were able to extrapolate that people who drank more than four cans or cups of soda per day were 30% more like to have been diagnosed with depression compared to those who did not drink soda.
Drinking four cans of sweetened fruit punch was shown to have a 38% increase when compared to no sweetened drinks at all.
What was interesting about these findings, and as noted above, is that the risk seemed to increase when people consumed the “diet” option over the regular version.
There is some good news to come out of this study however. Drinking four cups of unsweetened coffee was shown to present a 10% decrease in the likelihood of developing depression. This sits alongside existing research such as a 2011 study published in the Archives of Internal Medicine which suggested that women who drank fully caffeinated coffee had a lower risk of depression than non-coffee drinkers.
These findings are preliminary, which means there is still a lot of work to do to establish a direct link, however one of the culprits researchers are keen to investigate is the role of aspartame.
In summing up the study Chen says:
[The results] are intriguing and consistent with a small but growing body of evidence suggesting that artificially sweetened beverages may be associated with poor health outcomes.
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. More research is needed to confirm these findings, and people with depression should continue to take depression medications prescribed by their doctors.
To be clear, the researchers didn’t establish a causal link between sweetened drinks and depression. It is likely that sweetened drinks are just one aspect of a lifestyle that leads to increased risk of depression, other known factors that are relevant here including being overweight, poor diet and a lack of exercise.
However, this study does perhaps offer that excessive soft drink consumption should be seen as a warning sign for a potentially increased risk of depression, and does once again emphasize that choosing the “diet” option isn’t the healthy choice you might have thought.