Could Too Much Salt Harm MS Patients?
Researchers find a link but say it's too soon to recommend reducing sodium intake
By Steven Reinberg
THURSDAY, Aug. 28, 2014 (HealthDay News) -- Too much salt in the diet may worsen symptoms of multiple sclerosis (MS), a new study from Argentina suggests.
"Many environmental factors affect MS, such as vitamin D, smoking and Epstein Barr virus infection. Our study shows that high salt intake may be another environmental factor affecting MS patients," said lead researcher Dr. Mauricio Farez, of the Raul Carrea Institute for Neurological Research in Buenos Aires.
Multiple sclerosis is a disease of the nervous system that causes weakness, visual disturbances, trouble with balance, numbness and thinking and memory problems. The most common form is called relapsing-remitting MS, meaning symptoms subside and then become worse.
Earlier research found that salt may alter autoimmune response, which is involved in the development of MS.
Farez cautioned that this study does not show that salt causes MS to worsen, but there does seem to be an association.
"This is a small observational study showing a relationship between salt intake and MS disease activity, and these data need to be further validated in larger studies, including different populations," he said.
For the study, Farez's team measured the levels of sodium (the main component of salt), creatinine and vitamin D in the blood and urine of 70 patients with the relapsing-remitting form of MS. Creatinine is a marker of inflammation, and low levels of vitamin D have been associated with MS.
Sodium intake was divided into three levels: less than 2 grams daily, between 2 and 4.8 grams a day, and more than 4.8 grams daily. Current guidelines for heart disease prevention recommend a maximum sodium intake of 1.5 grams to 2.4 grams per day. At the upper end, that's just under half a teaspoon of table salt a day.
Farez's group found that people with daily sodium intake of between 2 and 4.8 grams and those who consume more than 4.8 grams -- a little less than a teaspoon of salt -- were up to four times more likely to have more episodes of worsening MS symptoms as those who consumed the least salt.