Careful with the salt – eat too much of it and your body may revolt.
That's what researchers writing for the journal Nature are saying, suggesting that a diet that's heavy in salt content could act as a trigger for certain autoimmune conditions.
There are more than 80 types of autoimmune diseases – multiple sclerosis, rheumatoid arthritis and type 1 diabetes are some of the more well-known conditions. They occur when the body's immune system, which attacks disease and infection, turns on itself and attacks healthy cells instead.
Experimenting with mice, researchers found that adding salt to their diets resulted in the production of a type of cell that was known to play a role in autoimmune attacks. They're called Th17 cells, and it's when they come into contact with salt that's potentially the problem.
"These are not diseases of bad genes alone or diseases caused by the environment, but diseases of a bad interaction between genes and environment," said senior author Dr. David Hafler in a statement.
In other words, in this case it's not the salt or the genes on their own that can cause a problem – it's when they come together.
Hafler added that human beings were "genetically selected for conditions in sub-Saharan Africa, where there was no salt" – a far cry from South Los Angeles, where the main thoroughfares might as well be shrines to the ubiquitousness of fast food.
"Today, Western diets all have high salt content and that has led to [increases] in hypertension and perhaps autoimmune disease as well," he said.
The researchers said over the past few decades, there's been a rise in the prevalence of autoimmune diseases. Hypertension, or high blood pressure, has also been seeing a rise: The Centers for Disease Control and Prevention said last year almost one in three adults have high blood pressure, and less than half of them have the condition under control.
Folks who are looking to take the findings of the study to heart might consider rethinking their consumption of what the American Heart Association dubbed the "Salty Six" – the "top sources of sodium in today's diet":
- Breads and rolls
- Cold cuts and cured meats
The research is still preliminary – the next step is clinical trials on (human) patients.