Research is still preliminary, but experts recommend people with MS avoid foods with high amounts of salt.
Salt causes inflammation in those living with multiple sclerosis.
And it may also trigger the disease.
A new study published in the journal Nature Immunology shows how salt disrupts T cells.
This disruption causes inflammation that may lead to MS exacerbations and progression.
The negative effects of salt on MS isn’t new.
A 2013 study conducted on mice showed a connection between an increase in cases of MS and a diet higher in salt.
“But more evidence was needed,” said Claude Schofield, PhD, director of discovery research at the National Multiple Sclerosis Society.
At the time, Dr. David Hafler, FANA, one of the study authors, said salt causes a “bad interaction between genes and environment.”
The results show how high salt intake can lead to increased inflammation.
The more recent study backs that up.
“Here’s even more evidence that salt causes inflammation,” Schofield told Healthline. “This is the second wave of research about MS and salt, building scientific evidence for increased inflammation.”
What salt does
This research shows how sodium affects T cells and causes inflammation.
“Salt affects signaling at the immune level, not the nerve level,” Schofield explained.
He describes the paper as technical, but explains that the mechanistic work that intertwines mouse and human studies shows how salt intake increases inflammation.
“Human work will always have more impact, but sometimes we need mice,” he said. “We are always looking for environmental factors that trigger MS.”
These are often risk factors that people living with MS have control over, therefore offering a self-care option.
“This study provides more evidence than the earlier papers,” Schofield said.
The study explains which cells are affected and how.
This offers “compelling evidence that high salt intake could lead to increased inflammation and could trigger in MS,” Schofield said.
The body excretes extra salt if too much is consumed. But salt could potentially fluctuate in microdomains, which are small regions of membrane, he explained.
“It might be premature to say that a modified sodium diet could alter the course of the disease,” Schofield said, “but I recognize that people with MS [are] looking for potential modifiable things they can do. I wouldn’t discourage cutting back on salt. This could help with co-morbidities [such as heart health and blood pressure].”
“This study looked at the molecular level. The next step would be to research at the clinical level,” he said.
Details of the study
The study was performed at Yale University in Hafler’s lab. He’s a professor of neurology and immunobiology as well as chair of the department of neurology and neurologist-in-chief at Yale New Haven Hospital in Connecticut.
Hafler told Healthline they were looking at the gut microbiome in relationship to inflammatory cells in the blood and in terms of diet and dietary history.
Those who ate fast food more than twice a week had higher instances of inflammatory cells.
In addition, if more salt was added, the inflammation increased.
“It became interesting [to examine] salt and potassium on the immune system,” Hafler said.
Watch your diet
Those who eat a Western diet are cautioned to be careful.
This diet is rich in red and processed meat, processed foods, fat, sodium, refined grains, sugar, fried foods, and butter.
“We should all be [eating a] low-fat, low-salt diet, 200 to 300 milligrams salt max,” Hafler advised. “The average daily consumption is 5 grams of salt. We need to do more work on this low-salt diet and see how [people] respond.”
“It is clear that salt affects the immune system,” he added. “Maybe with a disease like cancer we want this, but it may not be the case with MS.”
Hafler emphasizes that patients have options.
He recommends people living with MS to “eat healthy, get nutrition from actual food, and don’t smoke.”
Caroline Craven is a patient expert living with MS. Her award-winning blog is GirlwithMS.com, and she can be found on Twitter.