Higher Intake of Dietary Salt Worsens Symptoms of Multiple Sclerosis

A team of researchers has found that high dietary salt intake can worsen the condition of people with multiple sclerosis.

Multiple sclerosis affects more than 2. 5 million people worldwide including 400000 Americans. It is a nervous system disease that affects the brain and spinal cord. This disorder affects women more than men and is commonly diagnosed between the age group of 20-40 years. People with this disorder have problems with muscle movement, balance and vision. There is no complete cure for this disorder.

Studies conducted earlier have identified that salt may alter autoimmune response that is associated with the development of multiple sclerosis (MS).  But not much is known if it has a direct effect on the course itself.

In the latest study, the researchers analyzed the samples of blood and urine of 70 subjects with relapsing-remitting form of MS to evaluate the levels of salt. Salt is a marker of inflammatory activity known as creatinine and low levels of vitamin D is associated with the disease.

As a part of the study, the subjects were asked to give urine samples on three different occasions over a period of nine months to observe the changes in the intake of dietary salt. They tracked their neurological health for two years between 2010 and 2012.

They then measured the urinary salt levels in the second group that included 52 people with the same type of MS between June and July 2013.

In both the groups, the intake of salt averaged just above 4g per, but remained under 2g - 2-4.8 g to 4.8 g or more a day. When compared to women, men were more likely to consume more salt.

The association between levels of dietary salt and worsening symptoms remained same even after taking into consideration certain factors like smoking, age, gender, weight, treatment, circulation of vitamin D and the length of time after diagnosis.

"Compared with those consuming the least salt every day, those on moderate to high intake in the first group had around three more episodes of worsening symptoms, and were almost four times as likely to have these episodes," researchers said.

Even after looking at X-rays and scans to check if the disease progressed further, they noticed the link between dietary salt intake and radiological evidence.  Subjects with higher intake of dietary salt were 3.5 times more likely to have radiological signs.

"This is an observational study, so no definitive conclusions about cause and effect can be drawn. And higher levels of salt in the urine may reflect greater disease activity rather than the other way round. But high salt intake is implicated in various aspects of poor health, they say. And their findings suggest further research into whether dietary salt reduction could ease MS symptoms or slow the progression of the disease might now be warranted," they add.

The finding was documented in the British Medical Journal.