Iowa Alumni Magazine | June 2009 | News

Alan Kim Johnson

By IAM Staff

Why was he in the news?

Ever reach for the salt shaker before even tasting your food? UI psychologist and physiologist Alan Kim Johnson grabbed headlines this past spring when he uncovered an intriguing reason why—salt might make us happier.

By observing the behavior of rats, Johnson and his team noticed that rodents deficient in sodium chloride failed to participate in activities they normally enjoyed. Ultimately, the researchers concluded that salt deficiency could play a role in exacerbating one of the key symptoms of depression: the loss of pleasure in normally satisfying events.

What's the big deal?

Media outlets across the globe jumped to cover Johnson's findings. The professor says he's surprised by the response, but attributes much of the attention to the public's interest in depression.

Even though too much sodium chloride is known to raise blood pressure and contribute to other health problems, the notion that salt is a mood-elevating substance helps explain why many people seem to consume way more than they need. Johnson explains that eating salt activates pleasure mechanisms in the brain; in fact, salt cravings involve the same brain pathways as those related to drug abuse. It's an addictive substance, and Johnson's research points out possible theories for our desires, including evolutionary explanations for why our bodies demand salt. He explains that, as human origins began in prehistoric seas, our bodies still need sodium chloride to function properly. Hence, we developed an adept ability to crave, locate, and physiologically conserve the substance.

What's his advice?

Johnson's study does not suggest salt as a treatment for full-blown depression. However, anyone who makes a lifestyle change that might alter the body's sodium chloride content—say a low-salt diet or a rigorous exercise program—should keep these results in mind. If you make such changes and experience a persistent blue mood, you should mention your new lifestyle to your primary care physician. A salt deficiency could be to blame.