MS activity and dietary salt

Image courtesy: Dubravko Sorić via Wikipedia

Dietary salt (sodium) is an important element in our diet, with multiple roles, including control of blood pressure, blood volume, and requirement for the proper function of the muscles and nerves.  However, too much salt in the diet may lead to medical disorders, including high blood pressure, and contribute to a buildup of fluid in people with congestive heart failure, cirrhosis of the liver, or kidney disease.

A general diet guideline for sodium consumption for healthy adults is around 2300 mg per day; but for those individuals with high blood pressure this should be no more than 1500 mg per day, with even more restrictive levels recommended for individuals with congestive heart failure, liver and kidney disease.  1 teaspoon of table salt contains 2300 mg of sodium.

There has been interesting research recently on the role of salt in autoimmune disorders such as psoriasis, rheumatoid arthritis, and ankylosing spondylitis.  It has been found that salt levels can alter the expression of key inflammatory immune cells such as TH17 cells, the over production of which has been associated with these autoimmune disorders.  

New research, published in the Journal of Neurology, Neurosurgery, and Psychiatry looked at 2 groups of subjects with relapsing remitting MS.  The first group of 70 subjects was followed over 2 years, with data collected on clinical outcomes, MRI monitoring, and sodium intake.  Blood and urine samples were taken 12 months after enrollment.  Levels of salt and a marker for inflammatory activity were measured in the urine together with measurements of serum sodium (the concentration of sodium in the blood) and vitamin D levels.  The second group consisted of 52 subjects.  In this group random urine samples were collected and analyzed by following the same procedures as those used for the first group.  

This study found that both groups averaged an intake of just over 4 g of salt a day.  When taking into consideration the variables of age, gender, disease duration, smoking status, vitamin D levels, body mass index, and MS treatment, this study analysis showed an interesting link between dietary salt and MS symptom severity: Those subjects who consumed low levels of salt (2 grams or less daily) had a measurably lower level of their MS disease activity.  

Further, the MRI data showed signs of greater deterioration with higher dietary salt intake levels.  People taking high salt intake (4.8 g or more) were 3.5 times more likely to have MRI signs of MS disease progression than those with low salt intake.

The preliminary results from this study need to be validated in larger investigations.  However, the association found between increased salt intake and MS disease activity may point to yet another lifestyle factor which may be modified and have a meaningful impact on MS symptoms and progression.

Controlling dietary salt intake can be quite a challenge, particularly as we become more dependent on processed foods.  Closely reading food labels for salt content is a first step.  Having discussions with a dietician about healthy meal preparation, which emphasizes salt alternatives for seasoning can be very helpful.  EvergreenHealth sponsors a free nutrition seminar for individuals with neurological disorders, which meets monthly. For more information about this seminar, please contact EvergreenHealth Healthlines (425-899-3000).  

Watch for more news of a nutrition workshop for people with MS slated for August 1.