'A taste for salt can keep you feeling chipper,' reads the headline in the Daily Mail. The newspaper said that researchers suggest that salt may act as a 'natural antidepressant'. It said that while too much salt 'can lead to high blood pressure and heart disease, not enough could trigger 'psychological depressions''. The researchers found that rats deprived of salt 'began to behave erratically and shun foods and activities they normally enjoyed'.
The review behind this news story does not suggest that people should use salt as an antidepressant. Instead, it discusses some studies which suggest that a possible reason why we consume so much salt is because our body 'rewards' us for this behaviour. The authors give evolutionary reasons why this might be the case, and explore the biological and behavioural ways that our bodies promote and maintain this high salt intake.
As the authors state, most people on a modern Western diet consume more salt than they need. Too much salt can be harmful in the long term, and people should try to consume less salt than the recommended levels. The Food Standards Agency recommends adults should have no more than 6g per day, and 2g per day for children.
Where did the story come from?
Professor Alan Kim Johnson and colleagues from the University of Iowa carried out this research. The study was funded by the National Heart, Lung and Blood Institute, National Institute of Diabetes and Digestive and Kidney Diseases, and the American Heart Association. The study was published in the peer-reviewed journal Physiology and Behavior.
What kind of scientific study was this?
This was a non-systematic literature review in which the authors discussed the psychological and biological mechanisms that result in animals and humans consuming excessive amounts of salt (sodium chloride).
The researchers put forward their theories about salt intake, and discuss how their own and other studies in humans and animals have informed these theories. The specific methods of these studies are not presented in detail.
