Stress not the trigger for our increased salt appetite

Deakin University health researchers have found our over-consumption of salty foods is not fueled by stress, as has been previously proposed.

In trying to identify triggers for our increasing appetite for salt, Deakin health researchers Dr Susan Torres, Dr Anne Turner and Professor Caryl Nowson have considered potential physiological factors such as stress.

"It was proposed over 20 years ago that the salt intake of a society reflected the levels of stress and a physiological drive for salt would have been observed in our ancestors," Dr Torres said.

"Primitive humans developed processes to deal with stress (for example escaping a charging lion) such as increased blood pressure and heart rate. Responses to stress could also result in depletion in salt and consequently an increase in salt appetite to replace this salt."

In a paper published in a recent issue of the British Journal of Nutrition, the researchers evaluated evidence from animal and human studies to determine if stress induced a salt appetite in modern day humans, as it would have done in primitive times.

In reviewing recent research they found that this drive for salt after stress was reported in animals but was not evident in modern day humans.

"The primitive drive for salt is no longer evident in modern day humans," Dr Torres said. "This is not surprising given that the current food supply is so saturated with salt that most people are consuming amounts in excess of what the body requires."

Australians are eating up to 18 times more salt than is recommended, resulting in increasing rates of hypertension which is a risk factor for cardiovascular disease.

"The results of our study provide more evidence confirming that we are consuming far too much salt in the diet. It is important that all Australians cut back their salt intake to reduce their risk of developing chronic diseases such as cardiovascular disease," Dr Torres said.

(Source: Deakin University: British Journal of Nutrition: June 2010)