High dietary salt intake may worsen multiple sclerosis symptoms and boost the risk of further neurological deterioration, indicates a small observational study published online in the Journal of Neurology, Neurosurgery & Psychiatry.
Previous research has indicated that salt may alter the autoimmune response, which is implicated in the development of multiple sclerosis (MS), but it is not clear if it has any direct effect on the course of the disease itself.
The researchers assessed the blood and urine samples of 70 people with the relapsing-remitting form of MS to check for levels of salt; a marker of inflammatory activity called creatinine; and vitamin D, low levels of which have been linked to the disease.
This group were asked to provide urine samples on three separate occasions over a period of nine months to monitor changes in dietary salt intake, and their neurological health was then tracked for two years, between 2010 and 2012.
By way of comparison, urinary salt levels were measured in a second group of 52 people with the same type of MS between June and July 2013.
Salt intake averaged just over 4 g per day in both groups, but ranged from under 2 g (low) to 2-4.8 g (moderate) to 4.8 g or more a day (high), with men tending to have a higher daily intake than women.
After taking account of influential factors, such as smoking, age, gender, length of time after diagnosis, weight, treatment and circulating vitamin D, the analysis indicated a link between levels of dietary salt and worsening symptoms.
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.
The researchers then looked at x-rays and scans to find out if the disease had progressed further, and once again found a link between dietary salt intake and radiological evidence of further deterioration.
Those whose dietary salt intake was high were almost 3.5 times as likely to have radiological signs of further progression.
Similar results were obtained for the comparison group.
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, the authors point out.
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.
Source: MedicalXpress © Medical Xpress 2011-2014 (29/08/14)
People with multiple sclerosis who for one year followed a plant-based diet very low in saturated fat had much less MS-related fatigue at the end of that year — and significantly less fatigue than a control group of people with MS who didn't follow the diet, according to an Oregon Health & Science University study being presented today at the American Academy of Neurology's annual meeting in Philadelphia, Pa.
The study was the first randomised-controlled trial to examine the potential benefits of the low fat diet on the management of MS. The study found no significant differences between the two groups in brain lesions detected on MRI brain scans or on other measures of MS. But while the number of trial participants was relatively small, study leaders believe the significantly improved fatigue symptoms merited further and larger studies of the diet.
"Fatigue can be a debilitating problem for many people living with relapsing-remitting MS," said Vijayshree Yadav, M.D., an associate professor of neurology in the OHSU School of Medicine and clinical medical director of the OHSU Multiple Sclerosis Center. "So this study's results — showing some notable improvement in fatigue for people who follow this diet — are a hopeful hint of something that could help many people with MS."
The study investigated the effects of following a diet called the McDougall Diet, devised by John McDougall, M.D. The diet is partly based on an MS-fighting diet developed in the 1940s and 1950s by the late Roy Swank, M.D., a former head of the division of neurology at OHSU. The McDougall diet, very low in saturated fat, focuses on eating starches, fruits and vegetables and does not include meat, fish or dairy products.
The study, which began in 2008, looked at the diet's effect on the most common form of MS, called relapsing-remitting MS. About 85 percent of people with MS have relapsing-remitting MS, characterized by clearly defined attacks of worsening neurological function followed by recovery periods when symptoms improve partially or completely.
The study measured indicators of MS among a group of people who followed the McDougall Diet for 12 months and a control group that did not. The study measured a range of MS indicators and symptoms, including brain lesions on MRI brain scans of study participants, relapse rate, disabilities caused by the disease, body weight and cholesterol levels.
It found no difference between the diet group and the control group in the number of MS-caused brain lesions detected on the MRI scans. It also found no difference between the two groups in relapse rate or level of disability caused by the disease. People who followed the diet did lose significantly more weight than the control group and had significantly lower cholesterol levels. People who followed the diet also had higher scores on a questionnaire that measured their quality of life and overall mood.
The study's sample size was relatively small. Fifty-three people completed the study, with 27 in the control group and 22 people in the diet group who complied with the diet's restrictions.
"This study showed the low-fat diet might offer some promising help with the fatigue that often comes with MS," said Dennis Bourdette, M.D., F.A.A.N., chair of OHSU's Department of Neurology, director of OHSU's MS Center and a study co-author. "But further study is needed, hopefully with a larger trial where we can more closely look at how the diet might help fatigue and possibly affect other symptoms of MS."
Source: Science Codex (02/05/14)
Dietary salt associated with MS activity(07/10/13)
Sodium intake was positively correlated with risk of increased disease activity in patients with multiple sclerosis, according to a small study reported here.
Each gram of estimated daily sodium intake above the average in a 52-patient sample was associated with an increase of 3.65 in MRI lesion counts, said Mauricio Farez, MD, PhD, of Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia in Buenos Aires.
Also, patients with estimated salt intake classified as high -- more than 4.8 g daily -- showed relapse rates that were 3.95 times greater (95% CI 1.39-11.21) than those with intakes less than 2 g/day, he told attendees at the European Committee for Treatment and Research in Multiple Sclerosis annual meeting.
Farez emphasized repeatedly that the findings did not prove that high salt intake caused the increased disease activity. He acknowledged that, if there is a causal relationship, it possibly could go in the reverse direction -- that patients with highly active MS may increase their salt intake as a result. But he said he did not view that as very likely.
The study in a total of 122 patients with relapsing-remitting MS grew out of previous research connecting salt intake with vitamin D levels and body mass index, he said. Numerous studies have indicated an association between vitamin D status and MS risk -- including one reported minutes earlier at the Copenhagen meeting -- and it seemed logical to examine whether sodium may share a similar association, Farez explained.
He and colleagues initially recruited 70 patients for a first phase of the observational study. They underwent a baseline MRI scan in November 2010, followed by MRI scans and analysis of urinary sodium excretion as a means of estimating sodium intake 1 year later. Finally, in November 2013, relapse rates for the preceding 2 years were calculated.
During this first phase, the MRI analyses included "combined unique activity" counts -- the total of new T2 lesions and new gadolinium-enhancing T1 lesions since the baseline scan.
A second group of 52 patients was examined in June 2013 with MRI scans and urinary sodium testing to provide replication data for the association between sodium intake and MRI lesion activity. Because this group had only a single scan and no follow-up, Farez and colleagues could only calculate T2 lesion loads, not the combined unique activity lesion counts nor relapse rates.
Farez acknowledged that an important limitation of the study was that it did not measure urinary sodium excretion with 24-hour urine collections, which he said were impractical since they require participants to carry a large container to capture all their urine for a whole day and night.
Instead, his team relied on spot urine collections and a published formula to estimate daily sodium excretion and, from that, daily sodium intake.
He reported that, in the first group of patients, not only those with high sodium intake (more than 4.8 g/day) but also those with "average" consumption showed increased risk of relapse. Participants with estimated daily intake of 2.0 to 4.8 g/day had relapse rates that were 2.75 times that of the low-intake group (95% CI 1.30-5.81).
Comparing both the average- and high-intake groups, the trend was significant at P=0.001, he reported.
Also in the first group, combined unique activity lesion counts were approximately three times greater in both the average- and high-intake groups compared with the low-intake group (P not reported), Farez said.
And, T2 lesion counts were similar in the first cohort's low- and average-intake groups at an average of about 6, but they reached a mean of approximately 14 in the high-intake group (P<0.05).
In the replication set of 52 patients, similar results were seen, Farez said. He and his colleagues calculated that each increment in intake of 1 g above the cohort average was associated with 3.65-lesion increase in T2 count (SD 0.77, P<0.001).
He did not specify the cohort average, but he said that the national average in Argentina has been measured at nearly 5 g/day, well above the U.S. mean of 3.4 g/day.
The World Health Organization has recommended a maximum daily intake of 2 g/day. In the U.S., several government agencies have jointly called for a maximum of 1.5 g/day -- but earlier this year, the Institute of Medicine complained that the scientific evidence did not a support such a low figure, instead backing an older standard of 2.3 g/day.
Farez and colleagues also measured serum sodium but found no relationship between it and clinical or MRI activity. It was also not significantly associated with estimated sodium intake, with an R2 value of just 0.0082.
Asked by the session moderator what a causal mechanism might be, Farez said previous studies had suggested that high salt levels can promote increased inflammatory activity throughout the body. Also, he said, it may increase permeability in the blood-brain barrier, which could contribute to inflammation in the central nervous system.
Whatever such a mechanism may be, he said, "it does not seem to occur in peripheral blood."
The study had no commercial funding.
Farez reported a relationship with Merck Serono. Other investigators reported relationships with this firm and with Biogen Idec, Novartis, and Teva.
Primary source: European Committee for Treatment and Research in Multiple Sclerosis
Source reference: Farez M, et al "Sodium intake is associated with increased disease activity in multiple sclerosis" ECTRIMS 2013; Abstract 119.
Source: MedPage Today © 2013 MedPage Today, LLC (07/10/13)
Dr. Ikuo Tsunoda, Assistant Professor in the Department of Microbiology and Immunology at the Center for Molecular and Tumor Virology of the Louisiana State University Health Sciences Center, and colleagues reported that resveratrol, the polyphenol compound produced by the skin of red grapes and peanuts, worsened neuropathology and inflammation and had no neuroprotective effects in multiple sclerosis (MS) in the Oct. 1, 2013, issue of The American Journal of Pathology.
The researchers advise people that have MS or anticipate the development of MS to avoid resveratrol supplements as well as red grapes, peanuts, and red wine as a precautionary measure until further research defines the action of resveratrol in MS.
The researchers induced MS into test mice in two different forms. The diets of the test mice were compared with normal mice. One group of test mice ate a diet high in resveratrol. The other group of mice with MS ate a diet free of resveratrol.
The test mice that had MS and ate a diet high in resveratrol developed symptoms of MS earlier, had higher levels of inflammation, lost more myelin, and demonstrated slower recovery or no recovery from MS than mice that ate a diet free of resveratrol.
Resveratrol demonstrated no anti-viral effects in mice infected with Theiler's murine encephalomyelitis virus the virus used to induce MS like symptoms in test mice.
Source: examiner.com © 2006-2013 Clarity Digital Group LLC (03/10/13)