The amount of salt in our diet could be involved in driving our own immune systems to rebel against us, leading to diseases such as multiple sclerosis, early laboratory findings suggest.

Several teams of scientists have simultaneously published data in the journal Nature suggesting a link.

Salt may activate a part of the immune system that can target the body.

Experts said the findings were very interesting and plausible, but were not a cure for people with MS.

The body's defense against infection can go horrible awry, turning on the body and leading to autoimmune diseases including Type 1 diabetes, rheumatoid arthritis and multiple sclerosis.

Genetics is thought to increase the risk of such diseases, but the world around us also has a major impact. One of the leading theories behind multiple sclerosis is a viral infection, but smoking and a lack of vitamin D may make the condition more likely.

Now researchers believe they have the first evidence that the amount of salt in our diet may also be contributing.

Teams of researchers at the Brigham and Women's Hospital and the Broad Institute of MIT and Harvard were investigating a part of the immune system that has been implicated in autoimmune diseases.

Mice fed a high-salt diet were more likely to develop a disease similar to MS in experiments.

Meanwhile, researchers at Yale University were also investigating salt and looking at human cells.

David Hafler, professor of immunobiology at Yale, told BBC news online: "In mouse models of MS, those fed high-salt diets had significantly worse disease.

"We were all really quite surprised to see how changes in dietary salt could have such a profound effect."

Advice?

Commenting on the findings, Prof Alastair Compston, from the University of Cambridge, told the BBC the findings were plausible, unexpected and very interesting.

"Like all good science it is introducing a brand new idea that nobody had thought of."

He said that salt may have a similar effect to other factors such as smoking and sunlight, which alter the odds of getting the disease.

However he cautioned: "There is no prospect of a low salt diet curing MS. If you already have the disease and go on a low salt diet the horse has already bolted."

Dr Susan Kohlhaas, head of biomedical research at the MS Society, said: "This is a really interesting study and it's positive to see new avenues of MS research being explored in this way.

"It's still too early, however, to draw firm conclusions on what these findings mean for people with MS, but we look forward to seeing the results of further research.

"In the meantime, we recommend that people follow government advice on maintaining a healthy, balanced diet, which includes guidelines on salt intake."