A study involving more than 270,000 people in the UK Biobank linked adding salt to food to depression, with the likelihood of developing depression increasing by 20% for those who added it occasionally, and by 45% for those who added it always.
A similar Chinese study found that excessive salt intake increases the risk of depression by 37% and anxiety by 27%.
Experts point out that excess salt increases the production of an inflammatory protein called IL-17A, which raises blood pressure and affects the brain, disrupting the natural balance of chemicals that control mood.
Research on mice has shown that a salty diet raises levels of this protein and causes signs of low mood and stress, while these effects were not seen in mice genetically engineered not to produce IL-17A.
Salt has other harmful effects, as it has been found to increase the risk of dementia by between 19% and 73%, and to increase the likelihood of hearing loss by 23%, as a result of fluid imbalance in the inner ear.
Therefore, experts advise that salt consumption should not exceed 6 grams per day — slightly more than a teaspoon — whether from foods that contain it or from table salt.
The British Heart Foundation recommends reducing the consumption of processed meats, bread, pizza, sauces, biscuits and ready meals, while choosing low-salt foods such as cooked beans.
