New research claims that drinking sweetened beverages, especially diet drinks, increase the risk of depression in older adults while drinking coffee was tied to a slightly lower the chance of risk.

"Sweetened beverages, coffee and tea are commonly consumed worldwide and have important physical—and may have important mental—health consequences," said study author Honglei Chen, MD, PhD, with the National Institutes of Health in Research Triangle Park in North Carolina and a member of the American Academy of Neurology.

The study involved 263,925 subjects between the ages of 50 and 71 that were first collected from 1995 to 1996. Soda, tea, fruit punch and coffee consumption of the subjects were evaluated. After 10 years, the researchers asked the participants if they had been diagnosed with depression since 2000, and it was found that 11,311 had been diagnosed with depression.

People who drank more than four cans or cups of soda a day were 30 percent more likely to be depressed than those who did not drink soda. People who drank four cans of fruit punch a day were 38 percent more likely to experience depression than those who did not drink sweetened drinks. The chance of depression was greater in the people who consumed diet soda, fruit punch, and iced tea than regular ones.

However, people who consumed four cups of coffee per day were 10 percent less likely to develop depression than those who did not drink coffee.

"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," said Chen. "More research is needed to confirm these findings, and people with depression should continue to take depression medications prescribed by their doctors."

The study was released Jan 8 and will be presented at the American Academy of Neurology's 65th Annual Meeting in San Diego, March 16 to 23, 2013.