Diet and Nutrition in Multiple Sclerosis: Evidence, Microbiota, and Vitamin D

There is no single “universal” diet for multiple sclerosis (MS). However, a growing body of research shows that dietary patterns can influence inflammatory activity, immune regulation, gut microbiota composition, metabolic status, and overall quality of life in people with MS. Diet does not replace disease-modifying therapies (DMTs), but it can serve as an important additional factor capable of exerting anti-inflammatory and neuroprotective effects.

MS is an immune-mediated disease affecting myelin and axons in the central nervous system. Several modifiable physiological systems—gut microbiota, inflammatory pathways, nutrient status, and metabolic balance—may influence disease activity and symptoms.

How Diet Influences MS: Inflammation, Immunity, and Microbiota

• Gut microbiota modulation. A diverse diet rich in fiber, polyphenols, and plant-based foods supports beneficial bacteria that produce short-chain fatty acids (SCFAs), such as butyrate and propionate. These molecules enhance regulatory T-cell (Treg) activity, reduce Th17-driven inflammation, and strengthen intestinal barrier integrity. Dysbiosis in MS (e.g., increased Akkermansia) is associated with immune imbalance and can correlate with fatigue, anxiety, and depression.
• Vitamin D as a protective factor. One of the strongest modifiable environmental factors. Adequate serum 25(OH)D levels are associated with lower MS risk, reduced relapse activity, and possibly slower long-term disability progression. Vitamin D modulates cytokines, T-cell differentiation, and inflammatory pathways.
• Anti-inflammatory nutrients. Omega-3 fatty acids reduce IL-6, IL-1β, and TNF-α; antioxidants reduce oxidative stress—a major contributor to axonal injury in MS.
• Intestinal barrier and immune activation. “Leaky gut” may permit bacterial components to enter the bloodstream and activate immune responses. Fiber, polyphenols, and fermented foods improve barrier function, whereas saturated fats worsen it.
• Metabolic regulation. Obesity, insulin resistance, and dyslipidemia increase systemic inflammation and worsen MS outcomes. Diet can improve these pathways.

Key Nutrients in an MS-Friendly Diet

• Vitamin D. A critical modifiable factor associated with MS onset and activity. Supports immune regulation and may have neuroprotective effects.
• Vitamin B12. Essential for myelin formation. Deficiency may mimic or worsen neurological symptoms.
• Omega-3 polyunsaturated fatty acids (PUFAs). Reduce inflammation and support neuronal membranes.
• Calcium. Important for bone health; MS patients have increased risk of osteoporosis.
• Antioxidants. Vitamins A, C, E, polyphenols, carotenoids — reduce oxidative stress.
• Dietary fiber. Improves gut microbiota composition and reduces systemic inflammation.
The role of coffee in the diet of patients with multiple sclerosis is not fully understood, although an increasing amount of positive evidence is accumulating.

Recommended Foods for People With MS

• Vegetables and fruits (wide color variety daily)
• Whole grains (oats, whole wheat, quinoa, brown rice, barley, buckwheat)
• Lean proteins (fish, skinless poultry, legumes, tofu)
• Healthy fats (olive oil, avocado, nuts, seeds)
• Low-fat dairy (if tolerated)
• Adequate hydration

Mediterranean-style dietary patterns are associated with reduced inflammatory activity, improved cognition, less fatigue, and better overall quality of life in MS.

Foods to Limit or Avoid

• Saturated fats — red meat, butter, high-fat cheese, cream, pastries.
• Trans fats — fried foods, processed snacks, margarine.
• Excess sugar — sodas, sweets, baked goods.
• Highly processed foods — additives, preservatives, refined oils.
• Excess alcohol — worsens balance, coordination, fatigue, and bladder symptoms.

Controversial Dietary Components

• Dairy. Evidence is mixed. Moderate low-fat dairy is acceptable unless intolerance is present.
• Salt. High salt enhances Th17 activity in animal models; human data are inconsistent.
• Gluten. No evidence that gluten affects MS course unless celiac disease is present.

Detailed Overview of Popular MS Diets

Several specialized diets are widely discussed among patients with MS. Their evidence base is limited, but understanding them helps patients make informed and safe decisions. Below is a comprehensive overview.

1. Best Bet Diet

Based on the hypothesis of intestinal hyperpermeability (“leaky gut”) and molecular mimicry between dietary proteins and myelin.

Main principles:

• eliminates dairy, gluten, legumes, eggs, yeast;
• minimizes saturated fat, refined sugar, alcohol;
• emphasizes fish, lean meats, vegetables, nuts, olive oil;
• includes vitamin and omega-3 supplementation.

Evidence is anecdotal; no controlled clinical trials. Risk of nutrient deficiencies.

2. Intermittent Fasting and Caloric Restriction

Possible mechanisms:

• reduced pro-inflammatory cytokines (IL-6, TNF-α);
• enhanced autophagy and mitochondrial function;
• improved insulin sensitivity and gut microbiota composition.

Small studies show potential benefits in fatigue and mood. Risks include low body weight, menstrual irregularities, and reduced bone density.

3. Ketogenic Diet

A high-fat, very low-carbohydrate diet inducing ketosis.

Evidence:

• small RCTs show improvements in fatigue, depression, and quality of life;
• long-term effects on relapse rate or disability progression are unknown.

Risks include constipation, micronutrient deficiencies, dyslipidemia, kidney stones.

4. McDougall Diet

A very low-fat, whole-food, plant-based diet eliminating all animal products and oils.

Characteristics:

• all animal products excluded;
• minimal fats and oils;
• relies heavily on starches, vegetables, legumes.

One small study showed reduced fatigue; requires monitoring of B12, iron, zinc, calcium, vitamin D.

5. Mediterranean Diet

Core principles:

• abundant vegetables, fruits, leafy greens, legumes, whole grains;
• olive oil as primary fat (rich in monounsaturated fats and polyphenols);
• regular consumption of fish and seafood;
• limited red and processed meat, sweets, and trans fats.

Multiple studies show improvement in fatigue, cognition, mood, quality of life, and inflammation.

6. Overcoming MS (OMS) Diet

A plant-based, low–saturated fat diet that includes fish or omega-3 supplements, combined with stress reduction, exercise, and vitamin D optimization.

Observational studies associate OMS practices with better quality of life, though controlled trials are lacking.

7. Paleo Diet

Excludes grains, legumes, dairy, and processed foods. Contains vegetables, meat, fish, nuts, fruits. Evidence in MS is very limited.

8. Wahls Protocol

A structured, nutrient-dense modification of Paleo focusing on:

• 9+ cups of vegetables daily (leafy greens, sulfur-rich, colorful vegetables);
• micronutrient adequacy;
• exercise and stress reduction.

Small studies report improvements in fatigue and quality of life.

9. Swank Diet

Very low saturated fat diet developed in the 1950s, emphasizing fish, whole grains, fruits, vegetables, low-fat dairy, with recommendations for cod liver oil and multivitamins.

Long-term observational findings suggest potential benefits, but lack modern randomized evidence.

Practical Recommendations for Patients With MS

• Diet cannot replace DMTs but can support the immune system, gut microbiota, and overall health.
• The most balanced and sustainable pattern for most people resembles a Mediterranean-style anti-inflammatory diet.
• Vitamin D levels should be monitored and supplemented under medical supervision.
• Strict diets (keto, vegan, Paleo, Best Bet, Wahls) should be supervised by clinicians to avoid deficiencies.
• Consistency and long-term adherence matter more than strict rules or rapid changes.

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