Multiple sclerosis (MS) is a chronic, immune-mediated disease affecting the central nervous system (CNS), characterized by neuroinflammation and progressive neurodegeneration. It is estimated that globally, MS affects over 2.8 million individuals. The exact cause of MS is unknown, but it is believed to be a complex interaction between genetic and environmental factors that initiate the disease. Growing evidence suggests that dietary interventions may influence MS progression and symptom management by modulating inflammation, oxidative stress, and gut microbiota composition. Recently, the gut microbiome-the trillions of gut bacteria that live inside human intestines-has emerged as a potential environmental factor that contributes to MS. This article examines the effects of various dietary patterns, including plant-based diets, on MS, drawing from recent research and studies.
Understanding Multiple Sclerosis
Multiple sclerosis (MS) is a chronic immune-mediated disease of the central nervous system (CNS), characterized by inflammation, gliosis, and demyelination that progressively lead to neurological deterioration. Common symptoms include visual impairments, fatigue, cognitive decline, numbness, and disruptions in sensory and motor functions. MS manifests in two primary forms - relapsing and progressive - further categorized into relapsing-remitting MS (RRMS), secondary progressive MS (SPMS), and primary progressive MS (PPMS). RRMS, the most common subtype, affects approximately 85% of individuals and is characterized by episodes of neurological dysfunction followed by varying degrees of remission.
Diagnosing MS follows the 2017 McDonald criteria, which for RRMS requires evidence of clinical attacks and tissue damage occurring at different times and locations. PPMS diagnosis demands confirmation of progressive disability over at least 12 months alongside spatial lesion dissemination, while SPMS is diagnosed when disability progression follows an initial RRMS diagnosis. Although genetic predisposition plays a significant role in MS development, environmental factors - including infections, smoking, obesity, vitamin D deficiency, and diet - are equally critical in disease onset and progression.
The Role of Diet in MS
Diet plays a key role in MS, affecting immune function, inflammation, and neurodegeneration. While no single diet has been established as a definitive treatment for MS, emerging evidence suggests that certain dietary patterns may help manage symptoms and slow disease progression. Anti-inflammatory and neuroprotective diets, such as Mediterranean and plant-based diets, have been linked to reduced fatigue, improved quality of life (QoL), and modulation of inflammatory markers.
In contrast, diets high in saturated fats (SFAs), trans fats, ultra-processed foods (UPFs), and refined sugars may exacerbate inflammation, gut dysbiosis, and neurodegeneration, potentially worsening MS symptoms. High intake of SFAs and UPFs can disrupt gut microbiota, reducing beneficial species like Bifidobacteria and Lactobacilli while promoting inflammation. Trans fats, commonly found in hydrogenated oils, processed snacks, and fast foods, have also been linked to inflammation, while red meat, which is rich in arachidonic acid, may promote inflammation through T helper 17 cells (Th17 cell) activation. Excessive sugar intake raises insulin levels, which may indirectly enhance arachidonic acid metabolism and contribute to systemic inflammation.
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Oxidative stress also plays a key role in MS progression by generating reactive oxygen species (ROS) that damage neurons, degrade myelin, and amplify inflammatory responses. Antioxidants such as vitamins C and E, omega-3 fatty acids, and polyphenols may help counteract these effects.
Plant-Based Diets: An Overview
Plant-based diets emphasize the consumption of plant-derived foods while minimizing or eliminating animal products. These diets are often rich in fiber, vitamins, minerals, and antioxidants, which can have numerous health benefits, including reducing inflammation and supporting gut health.
Veganism
Veganism is a philosophy and lifestyle that extends beyond food to all animal products and by-products. The aim of veganism is to eliminate exploitation of animals completely. But veganism is more than a diet - for example vegans might not wear leather or wool products, buy products that are tested on animals, or visit zoos or aquariums. As such, veganism is more of a complete lifestyle choice.
A vegan diet may benefit people with multiple sclerosis (MS) by reducing inflammation, supporting cardiovascular health, and promoting a healthy weight, all of which can positively impact disease progression and symptom management.
Whole Food, Plant-Based (WFPB) Diet
A whole food, plant-based (WFPB) diet goes one step further than the Overcoming MS diet because it eliminates not only all animal products but also salt, oil and added sugars. This is intended to further improve health outcomes. The term ‘whole food, plant-based’ was coined by The China Study co-author T.
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A whole foods, plant-based (WFPB) diet may benefit people with multiple sclerosis (MS) by emphasising minimally processed plant foods that are rich in fiber, antioxidants, and anti-inflammatory compounds while avoiding added sugars, oils, and processed ingredients. This approach can help manage weight, improve cardiovascular health, and potentially slow disease progression by reducing inflammation and oxidative stress.
Vegetarianism
A vegetarian diet, especially one focused on whole, plant-based foods rich in fibre and antioxidants, may offer benefits for people with multiple sclerosis (MS). So, if you want to combine a vegan and Overcoming MS diet, what extra tips can you utilise to make the most of these guides?
Research on Plant-Based Diets and MS
Plant-based diets are being explored for their potential role in MS management, particularly due to their anti-inflammatory properties and ability to modulate gut microbiota. Studies indicate that individuals with MS exhibit gut dysbiosis. A case-control study of 148 MS patients and 148 healthy controls found significant differences in gut microbiota composition (p < 0.001). Among 61 bacterial species with altered abundance, 31 were more prevalent in MS patients, with some directly linked to inflammation markers (p < 0.05). These findings suggest that gut microbiota imbalances may contribute to MS-related inflammation, reinforcing the potential benefits of plant-based diets - rich in fiber, vitamins, and phytochemicals - in improving gut health and reducing inflammation.
Key Studies and Findings
Isoflavones and Gut Microbiome: The study led by Ashutosh Mangalam, PhD, UI associate professor of pathology, shows that a diet rich in isoflavone, a phytoestrogen or plant-based compound that resembles estrogen, protects against multiple sclerosis-like symptoms in a mouse model of the disease. Importantly, the isoflavone diet was only protective when the mice had gut microbes capable of breaking down the isoflavones. “Interestingly, previous human studies have demonstrated that patients with multiple sclerosis lack these bacteria compared to individuals without MS,” Mangalam says. Isoflavones are found in soybeans, peanuts, chickpeas and other legumes. The study also found that mice fed the isoflavone diet have a microbiome that is similar to the microbiome found in healthy people and includes the bacteria which can metabolize isoflavones. The team compared the effects of an isoflavone diet and an isoflavone-free diet on disease in the mouse model of MS. They found that the isoflavone diet led to disease protection. However, when the team placed the mice on the isoflavone diet but removed the isoflavone-metabolizing gut bacteria, the isoflavone diet was no longer able to protect against MS-like symptoms. When the bacteria were reintroduced, the protective effect of the isoflavone diet was restored.
Low-Fat, Plant-Based Diet and Fatigue: A first-of-its-kind controlled clinical trial found that a low-fat, plant-based diet significantly improved the health of people with multiple sclerosis by reducing both fatigue and weight. The study did not show differences in the MS lesions on brain imaging, relapse rate or disability in the two study groups - active and control. The study sheds new light on the role of diet as a treatment for people living with MS. Sixty-one people participated in the study, with 32 following the low-fat plant-based diet during the one-year study, and 29 who did not alter their diet. Researchers found no difference in MS-related lesions on the brain, relapse rate and disability between the two study groups. Researchers noted that the benefits of modern FDA-approved therapies for treating MS likely outweigh the effects of a plant-based diet in reducing disease activity.
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McDougall Diet: The McDougall diet is a low-fat, plant-based diet that many people with MS appear to benefit from. Another reason the McDougall diet would be a good idea is growing evidence that people with MS also have vascular disease risk factors, such as high cholesterol, hypertension, diabetes and heart disease. Although a special diet may help people with MS, there is no evidence of a magic bullet. That is, no diet helps everyone, although several offer some benefits. The McDougall diet is based on plant sources of complex carbohydrates and starch, such as wheat-flour products, corn, rice, oats, barley, quinoa, potatoes, sweet potatoes, beans, peas and lentils. Animal-derived foods are not allowed, from dairy to eggs, meat, poultry and fish. The one-year study involved 61 participants with MS who were assigned either to a diet or a waiting list. The second group, in other words, were a control group. Those assigned to the diet received a training at home through the McDougall Program, then were followed for 12 months. Physical checks and blood tests were done at the beginning of the study and at predetermined intervals afterward in the patients’ homes. The diet group ate starchy plant foods, but no meat, eggs, dairy products or vegetable oils. The control group followed their regular diet. Another small retrospective study on the effects of a seven-day McDougall diet resulted in changes in blood biomarkers used to predict a person’s risk for cardiovascular and metabolic diseases.
Systematic Review of Plant-Based Diet Trials: In the present review, 15 trials on 669 MS patients were included. The 2 plant-based diet trials, 1 was low-fat and the other was low-calorie, included in the review showed a large effect (ES: 0.6 to 0.7) on fatigue compared to the regular diet. The other plant-based diet was a low-protein diet and showed moderate to large effects on disability and RR compared to the Western diet. Our review showed that plant-based diets could be a central core for dietary recommendations. On the other hand, following low-fat, low-calorie, and low-protein plant-based diets for a long time induce nutritional deficiencies due to the limitations in the intake of some kinds of food groups such as dairy and grains. Thus, we recommend that MS patients correct plant-based diets with moderate intakes of some foods such as fish, poultry, and low-fat dairy to prevent the side effects of these diets.
Other Dietary Approaches and MS
Mediterranean Diet
Following a Mediterranean diet is associated with a roughly 40% reduction in risk of developing MS, according to a trio of researchers from the Karolinska Institute in Stockholm, Sweden. The researchers arrived at their conclusion by examining the dietary habits of 1,953 people during the five years before those study subjects were diagnosed with multiple sclerosis. After adjusting for factors including ancestry, smoking, alcohol consumption, body mass index, physical activity, and sun-exposure habits, they found that a Mediterranean diet was associated with a 41% reduction in risk of MS relative to a traditional Western-style diet.
A prospective observational study analyzed dietary patterns among 163 MS patients, categorizing them into three groups: Western, plant-rich, and varied. The plant-rich diet, which closely resembles the Mediterranean diet, demonstrated significant symptom reductions (19-90%, p = 0.012), including pain (90.1%, p = 0.022) and bladder dysfunction (90%, p = 0.031). Similarly, a randomized controlled trial (RCT) investigated the effects of a Mediterranean-like diet in 72 patients with RRMS over a 1-year period. The study found that the Mediterranean-like diet significantly improved fatigue scores (final fatigue score: 33.93 vs 37.98, p < 0.001) and reduced body mass index (BMI) (27.29-26.0, p = 0.02), suggesting potential benefits for physical health and QoL in RRMS patients.
A 12-month RCT carried out by Bagheri et al. on 100 MS patients found significant improvements in fatigue levels (30% reduction, p < 0.001) and cognitive scores (15% improvement, p < 0.01) following adherence to a Mediterranean-like diet. QoL also improved by 20% (p < 0.005). However, the study lacked imaging data to assess neurological changes. A systematic review and network meta-analysis of randomized trials assessed the efficacy of eight dietary interventions: low-fat, Mediterranean, ketogenic, anti-inflammatory, Paleolithic, fasting, calorie restriction, and a control diet on fatigue and QoL in MS. The results indicated that the Mediterranean and Paleolithic diets led to a greater reduction in fatigue compared to the control diet. These diets also showed greater improvements in both physical and mental QoL.
Swank Diet
Developed by Roy Swank, MD, PhD, the Swank diet was perhaps the first eating plan designed specifically for people with MS. People are advised to not eat any red meats during their first year on the diet, and to consume only three ounces of red meat per week thereafter. Skinless white-meat poultry and white fish are permitted. Dairy products generally are limited to those containing 1% or less of butterfat. People are encouraged to eat whole grain breads, rice, and pasta, and as many servings of fruits and vegetables as they wish. They also are encouraged to snack on nuts and seeds.
Swank recruited a group of 144 people with MS and asked them all to follow a very low saturated fat diet (15g/day, which is equivalent to 1.5 ounces of cheddar cheese or 1.5 pints of milk). Some people stuck with the diet (compliant) and some did not (non-compliant). Swank published his results 3.5 years, 5 years, 7 years, 20 years, 34 years and 50 years after the study began. The results showed that for those who complied with the low saturated fat diet, 95% remained physically active. However, for those who did not comply with the diet, only 7% remained physically active. 20% died from MS in the compliant group whereas 80% of those who did not comply with the diet died of MS causes.
Wahls Protocol
Developed by Terry Wahls, MD, who is a physician, medical researcher, and person living with MS, this approach emphasizes consumption of vegetables (particularly leafy greens), berries and other brightly colored fruits, meat and fish, and omega-3 fatty acids, plus other fat from animals and plants. Dr. Wahls reports that this diet dramatically improved her health and physical function.
Ketogenic Diet
Like classic ketogenic diets, the Atkins diet was developed by cardiologist Robert C. Atkins in the 1960s and is based on low-carbohydrate intake. The KD group had a daily consumption of less than 50 grams of carbohydrates, less than 100 grams of proteins, and more than 160 grams of fats. Finally, the study showed the beneficial effect of the KD on QOL after 3 and 6 months (P < 0.005, ES: 0.3-0.5).
Challenges and Considerations
Despite promising findings, limitations such as small sample sizes, short follow-up durations, and study design inconsistencies prevent definitive conclusions. It’s also important to think about how easy or difficult a particular diet is to follow over the long term.
Need for More Research
Future research should prioritize large-scale, long-term randomized controlled trials to establish the efficacy, safety, and sustainability of dietary interventions in MS management.
Consulting Healthcare Professionals
Identifying the diet plan that is best for you, and then working it into your daily life and following it over the long term, can be challenging. In fact, you should always talk with your primary care provider or neurologist before embarking on a new approach to your diet.