Multiple sclerosis (MS) patients eat a more limited diet, with a lower average of 31 nutrients, including zinc, thiamin, and iron, when compared with healthy controls, a study shows.
Blood tests also showed that MS patients had significantly lower iron levels, a different fatty acid composition in their red blood cell membranes, and significantly lower total serum antioxidant capacity.
The study, “New Insights on the Nutrition Status and Antioxidant Capacity in Multiple Sclerosis Patients,” was conducted in Israel, and published in the journal Nutrients.
The etiology of MS is multifaceted, and includes genetic and environmental factors. Nutrition is considered an important environmental variable that can influence the gut microbiome, metabolism, and immune function.
To gain insights into possible nutrition-related differences between MS patients and healthy controls, investigators collected questionnaires detailing the quantity and type of food eaten by people in two experimental groups. They also took blood samples to measure the levels of selected nutrients, and the total antioxidant capacity in serum.
Because the brain is an organ with high lipid (fat) concentrations, researchers hypothesized that there could be differences in the fatty acid composition of neuronal cell membranes. However, because direct access to brain lipids is not possible, they tested the fatty acid profiles of red blood cell (RBC) membranes as surrogate cells.
The study included 146 participants, including 63 MS patients (mean age at diagnosis 33.9 years; mean disease duration 10.4 years), and 83 healthy volunteers as a control group. Gender, ethnicity, body mass index (BMI), and age at enrollment were comparable between the MS and control groups.
MS patients were subdivided into two groups: those with mild disease (with an Expanded Disability Status Scale, or EDSS, between 0 and 3) and severe disease (EDSS equal or higher than 3.5). EDSS is a method of quantifying disability in MS patients. There were 40 mild MS and 23 severe MS patients in the cohort analyzed.
Results showed that in general, MS patients consumed a more limited diet compared with healthy controls, indicated by a lower average of 31 nutrients. MS patients consumed 15.1% fewer calories, 25.7% less protein, 19.5% less dietary fiber, 28.4% less cholesterol, and reduced amounts of 11 amino acids compared with healthy controls.
MS patients also consumed 23.7% less calcium, 25.3% less phosphorus, 25.4% less potassium, 26.9% less sodium, 27.35% less iron, 29.5% less zinc, 31.8% less copper, and 32.3% less magnesium.
The amount of iron consumed and the levels measured in blood were also significantly lower in MS patients, with the lowest levels seen in those with severe MS.
“Metal homeostasis [equilibrium] plays a critical role in regulation of the central nervous system, and is essential for normal functioning,” researchers said. Moreover, “metal deficiencies have been found in the serum of MS patients, specifically iron, magnesium, lithium, and zinc, and metal imbalances have been linked to demyelination, perhaps involving oxidative stress.”
MS patients were also found to consume fewer B vitamins, including niacin (19.7% less), folate (24.1% less), thiamine (26.8% less), vitamin B6 (27% less), and riboflavin (27.6% less). The team pointed out that “several human studies support the protective role of B vitamins in MS incidence and progression.”
The researchers also noted that the levels of zinc and thiamin in MS patients were significantly lower than the recommended daily dose.
The consumption of fatty acids was found to be significantly different between MS patients, with those with severe MS showing a significantly higher consumption of linolenic acid, the precursor of omega-3 fatty acids (found in fish and considered protective to the heart).
However, no significant difference was found in fatty acids, including in the omega-3 index, “although there was a trend toward lower omega-3 values in MS patients as compared to controls,” researchers said.
Also, no association was found between the intake of antioxidant vitamins (A, C, D, E, and carotene) and MS disease progression. However, the total antioxidant capacity measured in serum was significantly lower in the MS group compared with healthy controls, and the lowest levels were seen in patients with severe MS.
The team theorized that MS patients could consume less food because of disability issues, such as difficulty swallowing and/or the influence of mood on appetite.
Finally, the analysis of RBC membranes showed that out of the 26 measured fatty acids, nine showed significant differences between the groups — MS patients had lower levels of six fatty acids and higher levels of three fatty acids when compared with healthy controls. Some of these differences were particularly evident in patients with severe disease.
These specific differences suggest that MS patients have unique fatty acid profiles on their cell membranes.
However, according to the team, “as the actual value differences between group means were small even when significant, we cannot be sure regarding their clinical meaning or relevance.”
Taken together, the results suggest “a possible correlation between nutritional status and MS. Understanding the clinical meaning of these findings will potentially allow for the development of future personalized dietary interventions as part of MS treatment,” the researchers concluded.