When you’re cooking up a storm with the Christmas bird and all the trimmings, spare a thought to going easy on the salt – in the veg, stuffing, gravy and on the table. Otherwise too much could fray tempers. Yes, salt can cause stress.
Over the years we’ve been encouraged to cut down on added salt, with manufacturers pushed to lower levels of it in their products.
Salt is implicated in raising blood pressure and cutting down can have a beneficial effect. But, according to Edinburgh University research, it can do more harm than that. Salt can contribute to increased levels of stress.
The Edinburgh scientists found a high-salt diet increased the levels of a stress hormone by 75% in mice, and the results are interesting.
As it stands, the recommended salt intake for adults is less than six grams a day but most people regularly eat about nine grams.
This, as we know, can contribute to higher blood pressure, which in turn increases the risks of heart attacks, strokes and vascular dementia.
However, while effects on the heart and circulatory system have been well established, little was known about the impact of a high-salt diet on a person’s behaviour and this is what the Edinburgh University scientists were interested in.
To study this they used mice, who ordinarily have a low-salt diet, and gave them a high-salt food to parallel our typical intake.
They found not only did resting stress hormone levels increase, but also the hormone response in the mice to environmental stress was double that of the ones on a normal diet.
Crucially, salt increased the activity of genes responsible for brain proteins that control the body’s response to stress.
Experts say further studies are already under way to understand if a high-salt intake leads to other behavioural changes such as anxiety and aggression. So, does salt not only affect physical health but mental health too?
“We are what we eat and understanding how high-salt food changes our mental health is an important step to improving wellbeing,” comments Professor Matthew Bailey at Edinburgh University’s Centre for Cardiovascular Science.
“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.”