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Study finds too much salt can damage immune cell function

Indulging in salty foods does not only expose you to cardiovascular diseases and obesity, it also causes temporary damage to human immune cell function.

A higher sodium concentration in the blood has been found to weaken the mitochondrial function in white-blood cells, called monocytes. 

Mitochondria are found in almost all human cells and are a source of energy for the cells through the production of adenosine triphosphate.

Regular and prolonged mitochondrial malfunction could potentially cause blood-vessel inflammation and autoimmune diseases, according to a joint study by the Max Delbrück Centre for Molecular Medicine and the Experimental and Clinical Research Centre (ECRC), which was released in April.

The study investigated how sodium intake affects human cells by giving participants 6g of salt in tablet form each day for 14 days, while they continued with their normal diets. 

In another study, participants were given pizza with 10g of salt. 

“The findings showed that the dampening effect on mitochondria doesn’t just occur after an extended period of increased salt intake — it also happens after a single pizza. 

“Data from the pizza experiment showed how long the effect lasted. Blood was taken from the participants after three and eight hours, and the effect was barely measurable in the second sample,” according to the study. 

The ECRC’s laboratory head, Dominik Müller, said: “That’s a good thing. If it had been a prolonged disturbance, we’d be worried about the cells not getting enough energy for a long time.”

But it is advisable to keep salt intake regulated to stay healthy and less vulnerable to blood vessel and joint inflammation possibilities.

According to the South African Medical Journal (SAMJ), the average salt intake in South Africa is about 8.1g a day, which is higher than the 4g to 6g a day recommended by the World Health Organisation.

The SAMJ study confirmed that a South African diet is high in salt, with bread contributing to 25% to 40% of sodium intake. 

“Measured by 24-hour urinary sodium excretion, [intake] is 7.8g in black persons, 8.5g in mixed-raced, and 9.5g in white persons,” the study reads. 

The Harvard School of Public Health suggests that a healthy person would need at least 0.5g of sodium daily for vital functions, but an adequate intake was about 1.5g for any person older than 14 years, whereas a chronic disease-risk-reduction sodium intake is kept at 2.3g a day

This would mean that the average healthy person, including pregnant women, should not take in more than a teaspoon of salt in their diet each day.

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