High salt diet may lead to more stress

A recent study showed that a high salt diet increased stress levels in mice by 75 percent.

While extensive research has shown the effects of a high salt diet on the heart and circulatory system, few studies have explored salt’s effects on emotional behavior. For this study, published in the journal, Cardiovascular Research, researchers from the University Edinburgh in Edinburgh, Scotland, sought to better understand the relationship between a high-salt diet and stress.

For their investigation, researchers used mice who had previously had a low salt diet and gave them a high salt diet proportional to the average human intake of salt. According to the study, the recommended salt intake is less than six grams per day, yet most people consume more than nine grams a day.

Researchers conducted several tests before and after the trial to determine the mice’s stress hormone levels and stress-related gene activity in the brain. The study showed that after eating a high salt diet, the mice’s resting stress hormone levels increased and the mice’s hormone response to environmental stress was doubled. In addition, the salt intake increased the activity of genes that produce proteins in the brain that control the body’s response to stress.

Researchers concluded that these results suggest that chronic high intake of salt can increase levels of stress-related hormones. In the future, they hope to study the effects of salt on aggression and anxiety.

"We are what we eat and understanding how high-salt food changes our mental health is an important step to improving wellbeing,” said researcher Matthew Bailey, PhD, professor of renal physiology at the University of Edinburgh. “We know that eating too much salt damages our heart, blood vessels and kidneys. This study now tells us that high salt in our food also changes the way our brain handles stress."