4.1. Calories (Kilojoules)
Obesity during childhood increases the risk of developing MS [90
]. The European Society for Parenteral and Enteral Nutrition (ESPEN) guideline for clinical nutrition in neurology recommends preventing obesity in adolescence and young adulthood for the prevention of MS [92
]. Elevated BMI has been associated with increased disability and risk of relapse [93
]. Obesity also increases the risk of brain volume loss once MS has developed [94
]. Individuals with MS may also be at risk for malnutrition, especially individuals with dysphagia who have difficulty consuming adequate energy and nutrition; the ESPEN recommends routine screening for dysphagia and early detection and treatment of malnutrition in pwMS [92
]. The 2015–2020 Dietary Guidelines for Americans (DGA) which provides advice for consuming a healthy diet to reduce risk for diet-related chronic diseases also recommends individuals consume energy appropriate for attaining a healthy weight [42
Swank advised his patients to consume carbohydrate in sufficient quantity to meet energy needs, however, he observed that his patients lost weight because of reduced energy intake [23
] and underweight patients had better outcomes [20
]. Their weight was typically 5–10% below normal and Swank encouraged them to maintain the lower weight [55
]. Dr. Wahls also recommends individuals consume sufficient energy to achieve and maintain a normal body mass index (BMI). However, despite advising participants to consume adequate energy she also observed weight loss among pwMS following her diet for 12 months which resulted in an average 7.7% (+1.8 to −23.9%) kg/m2
reduction in BMI [33
]. Neither diet recommends fasting.
4.2. Fruits and Vegetables
Fruits and vegetables (F/V) have high nutrient density and are associated with decreased total and cardiovascular mortality [95
]. Low micronutrient intake may be associated with higher rates of neurodegeneration [96
]. The DGA recommends consuming vegetables daily and specific quantities of dark-green, red/orange, beans/peas, starchy (e.g., white potatoes, peas, corn) and other vegetables (e.g., green beans, onions, iceberg lettuce, celery, cabbage) throughout the week [42
]. The DGA Healthy US-Style Pattern (HEP) also recommends daily consumption of one and a half to two and a half or more cup-equivalents of fruit, especially whole fruit, per day depending on energy level [42
]. There is no specific F/V recommendations for pwMS beyond the DGA, however, a pediatric MS study found risk for relapse reduced by 50% with a one cup increase in vegetables [62
F/V are allowed in unlimited quantities on the Swank diet with the minimum recommended vegetable amount similar to the 1600 kcal (6694 kJ) DGA HEP but less than suggested for higher energy levels [42
]. However, specific recommendations for amounts of dark-green, red/orange and other vegetables subgroups are not provided. The DGA available in 1987, the year Dr. Swank published The Multiple Sclerosis Diet Book. A Low-Fat Diet for the Treatment of M.S.
], included general advice to consume a variety of foods but no recommendations for quantities of specific F/V subgroups [97
]. High fat vegetables such as avocado and olives are counted towards the oil intake on the Swank diet (see Section 4.6.3
. Monounsaturated and Polyunsaturated Fatty Acids).
The WahlsElim diet recommends nine or more servings of F/V per day, more than the DGA HEP, and in a very specific pattern of two to three+ servings each of green leafy vegetables, sulfur-rich vegetables and deeply pigmented F/V with a goal of 200 or more different plant species per year. The additional spices, herbs and plant species increases phytochemical diversity and may reduce inappropriate and excessive inflammation [98
]. Eating more non-starchy vegetables, resistant starch and soluble fiber plus fermented foods from allowable foodstuffs (see Section 4.12.3
. Fermented Food) are recommended with the goal of passing one to two soft bowel movements daily to reduce constipation, a common symptom [100
] in pwMS.
Dark-green leafy vegetables, an important recommended F/V component of the WahlsElim diet, are excellent sources of vitamin K and carotenoids. The recommended numbers of dark green leafy servings are greater than the DGA HEP amounts. Vitamin K is involved in sphingolipid metabolism, cell membranes, enhances remyelination and oligodendrocyte precursor cells [101
]. Vitamin K is metabolized by gut bacteria into vitamin K2mk7 which facilitates absorption of ectopic calcium from blood vessels back into the blood stream and mineralization of teeth and bones [105
]; enhanced absorption may be especially important on the WahlsElim diet because dairy products, a good source of calcium, are eliminated and the diet may be low in this nutrient. Carotenoids are precursors to retinol (vitamin A) which improves the balance between Th17 cells and T Regulatory cells. Retinol is considered an important target in the control of MS disease activity [107
]. β-carotene is converted to vitamin A in the intestine by the enzyme β-carotene-15,15’-monoxygenase (BCMO1) to support vision, reproduction, immune function and cell differentiation. However, considerable variability in BCMO1 exists and can affect individual vitamin A status with some single nucleotide polymorphism (SNP) variations having a 69% decrease in enzymatic efficiency [109
]. Therefore, the diet also includes other vitamin A sources in retinol (preformed vitamin A) from organ meat (see Section 4.3.2
. Organ Meat) and cod liver oil (see Section 4.13.1
. Cod Liver Oil).
Cabbage and onion family vegetables and culinary mushrooms are another recommended vegetable category on the WahlsElim diet. These foods are rich sources of organic sulfur. Sulfur may protect from neuro inflammation and/or neurodegeneration and provide favorable modulation of immune cell function [111
]. Diets high in sulfur may also reduce the risk of heavy metal toxicity [114
]. Culinary mushrooms have a long history of medicinal use as favorable modulators of immune response [115
]. Lion’s mane mushroom has been associated with increased production of nerve growth factors [119
Deeply pigmented F/V are the third recommended F/V category on the WahlsElim diet. These foods, especially berries, are associated with higher polyphenol and antioxidant content [120
] which is associated with decreased risk of cognitive decline [126
] and neurodegeneration [128
]; higher polyphenol phytochemical content may be anti-inflammatory and immune modulating [99
]. A variety of colors are encouraged on the WahlsElim diet: red, yellow/orange, blue/black/purple and green.
On the WahlsElim diet, white F/V (e.g., potatoes, bananas, apples, pears) consumption is discouraged until leafy, sulfur and colored F/V guidelines are met. Although white F/V provide dietary fiber and other beneficial components [130
], these F/V are often preferentially consumed instead of deeply colored F/V. Delaying consumption of white F/V is a dietary strategy to help promote consumption of leafy, sulfur and deeply colored F/V. Although apples have colored skin, the majority of the apple is white and the fruit is therefore classified as “white”; by contrast, “colored” F/V are colored throughout. Two other white vegetables, onions and cauliflower, are included in the sulfur-rich group. White potatoes are also excluded because they are nightshades.
Nightshades are avoided on the WahlsElim diet. White potatoes, tomatoes, eggplant and peppers are members of the nightshade (Solanaceae) family. Nightshades contain lectins and alkaloids, which may cross react with autoantibodies and increase disease activity in systemic autoimmune disease [86
]. These lectins and alkaloids may negatively disturb nerve, brain, muscle and digestive functions in the body. Eliminating nightshades may decrease inflammation as well as lower pain in joints and muscles and reduce brain symptoms. Lectins are found in wheat, legumes, nuts, seeds and white potatoes and are associated with an abnormal immune response in genetically vulnerable individuals [86
]. Susceptible individuals who consume large amounts of lectins may experience damage to their gut lining causing increased intestinal permeability which may allow bacterial fragments such as lipopolysaccharide (LPS) and incompletely digested food proteins to enter the blood stream. These protein fragments may trigger an immune response potentially culminating in autoimmune disease. Increased intestinal permeability is seen in MS [134
]. It has been proposed that greatly reducing lectin load may reduce symptoms in some susceptible individuals [86
]. Soaking grains, nuts, seeds and legumes will reduce the lectin content; using high pressure cooking for nightshades, grains and legumes will denature the lectin, making the foods less inflammatory but will not denature gluten and may not denature casein [136
]. Fermentation is another option for reducing lectins [137
]. Nightshade foods may be re-introduced to the WahlsElim diet one ingredient at a time after three months; these foods may be consumed if no increase in neurological or medical symptoms is observed in the week following reintroduction.
4.3. Protein Foods
The DGA recommend consuming five ounce-equivalents (142 g) of protein foods per day for the 1600–1800 kcal (6694–7531 kJ) Healthy US-Style Pattern (HEP) diets and a variety of protein types over the course of a week including meat, poultry, eggs, seafood, nuts, seeds, beans and peas and soy [42
]. Eight ounces (227 g) of seafood is recommended per week for 1600–2000 kcal (6684–8368 kJ) diets and four ounces (113 g) nuts, seeds and soy per week for 1600–1800 kcal (6684–7531 kj) diets [138
]. Healthy vegetarian diet patterns are also available in the DGA which exclude meat and poultry [42
There are no specific protein recommendations for pwMS beyond those for the healthy population. However, some limited evidence shows potential benefit for consumption of fatty fish. A pilot study of patients with mild ulcerative colitis eating 600 g of Atlantic salmon per week showed reduced inflammatory bowel disease activity after 8 weeks [140
]. An Australian case-control study found a higher intake of omega-3 fatty acids from fish associated with reduced risk of first demyelinating event although fat from supplements was not assessed [141
]. Alternatively, one physician (McDougall) advocates a vegan low fat diet to treat MS that emphasizes starchy foods (e.g., grains, tubers, legumes) plus vegetables and fruit [142
]. A 12 month randomized trial investigating this vegetarian (no meat, fish, eggs, dairy or vegetable oils) low (14%) fat diet compared to a usual diet (~40% fat) found improvements in fatigue, weight and blood lipids but no change in disease activity [27
The Swank and WahlsElim diets are not vegetarian diets, however, the amount and types of protein foods vary between the diets as described below. Swank did not clearly prescribe a daily target protein amount other than it should be of adequate “quantity and quality” ([48
] p. 126); one of his early publications recommended 50 g or more protein per day [20
] and his book referenced 1.0 g protein/kg body weight ([48
] p. 101). Protein containing foods are not restricted on the Swank diet except for those imposed by the requirement to limit saturated fat to ≤15 g per day. The WahlsElim diet does not prescribe a specific total protein goal but the minimum 6 ounce (170 g) recommendation for meat/fish intake alone (Table 1
) meets or exceeds the DGA recommendation for diets with ≤2200 kcal (9205 kJ) and provides approximately 42 g protein, with additional protein contributed by nuts and vegetables.
The Swank diet excludes beef, pork, organ meat, dark meat poultry and poultry skin during the first year because of the higher saturated fat content. Swank recognized the beneficial components in fatty fish and included them in the diet in limited amounts that kept the diet within the fat guidelines. Fat from fatty fish are counted toward oil intake (see Section 4.6.3
. Monounsaturated and Polyunsaturated Fatty Acids).
Meat and fish are recommended for the WahlsElim diet because they contain all essential amino acids and most other sources of protein are eliminated on this diet (e.g., grains, legumes, dairy, eggs). However, the recommended meat and fish intake is lower than most Paleo diets to reduce the activity of mammalian target of rapamycin (mTOR), insulin and insulin-like growth factor [143
]. High levels of insulin are associated with higher risk of insulin resistance, metabolic syndrome and obesity [144
]. High levels of mTOR are associated with imbalance of T cell homeostasis and increase of autoimmunity [145
]. Inhibition of insulin-like growth factor is a potential target of therapy for another autoimmune condition, rheumatoid arthritis [146
Grass fed and finished meats, wild game and wild caught fish and shellfish are also encouraged on the WahlsElim diet within the financial means of the individual to increase intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (see Section 4.6.3
. Monounsaturated and Polyunsaturated Fatty Acids). Although fatty fish are better sources of omega-3 fatty acids than meat, grass fed animals have higher amounts of omega 3 fatty acids than those that are grain fed [147
] which provide a more favorable omega 6:omega 3 ratio (see Section 4.6
. Fats). The WahlsElim diet recommends 16 ounces (454 g) fatty fish per week, more than included in the HEP.
4.3.2. Organ Meat
Organ meat is not specifically mentioned in the DGA but it is included as part of their meat subgroup [42
]. Organ meat is not allowed on the Swank diet during the first year due to the high saturated fat content; limited amounts of 3 ounces (85 g) per week are allowed after one year on the Swank diet [48
]. The WahlsElim diet encourages consumption of organ meats, especially liver, to increase nutrient intake and prevent deficiency. They are good to excellent source of B vitamins, vitamins A and D, phosphorus, zinc, selenium, copper and manganese. Liver is an excellent source of retinol (preformed Vitamin A) which is an important nutrient in bone metabolism, immune cell function, retinal health and cell differentiation. It is also an excellent source of choline and coenzyme Q10 [148
Swank allows an unrestricted amount of egg white but limits whole eggs to three per week because of the high saturated fat content of the yolk [48
]. Eggs are normally allowed on a Paleo diet [149
] but they are avoided on the WahlsElim diet because eggs are a common food allergen, especially in children [150
]. More than 70% of individuals with inflammatory bowel disease react to egg albumin [151
], 60% of seasonal allergy patients have IgG antibodies to eggs [152
] and 13% of adults with seasonal allergy have IgG antibodies to eggs [153
]. Eggs along with wheat and milk are common food triggers to Eosinophilic Esophagitis [154
4.3.4. Nuts and Seeds
Swank recommends nuts for snacks [48
]. Because of the high fat content, nuts and seeds must be counted towards oil intake on the Swank diet (see Section 4.6
The quantity of nuts and seeds is limited to four ounces (113 g) per day on the WahlsElim diet to avoid excess energy intake and provide an omega 6:3 ratio approximately 4:1 [155
]. This maximum daily quantity of nuts is higher than the weekly DGA recommendation for nuts, seeds and soy on the HEP [138
]. Traditional preparation of nuts and seeds often utilize soaking and sprouting which increases enzyme activity and reduces lectin activity [136
]. Soaking begins the germination phase which reduces the lectin content thereby reducing the probability of an abnormal and excessive immune response [156
]. For this reason, the WahlsElim diet recommends soaking nuts and seeds for 6 to 24 hours and then rinsing to reduce lectin content (see Nightshades in Section 4.2
. Fruits and Vegetables); individuals should consume soaked nuts/seeds immediately or dry in a dehydrator or oven for later use.
Legumes (e.g., dried beans, peas, green beans, soybeans, soymilk, peanuts) are not specifically mentioned as a food group by Swank. However, the recipes in his book [48
] include legumes. Peanuts are allowed on the Swank diet if they are counted towards the daily oil allowance (see Section 4.6
. Fats). Legumes are excluded on the WahlsElim diet and are typically avoided on a Paleo diet [149
]. Legumes are high in lectins and are also avoided on the WahlsElim diet for this reason (see Nightshades in Section 4.2
. Fruits and Vegetables).
Grains, especially whole grains, are recommended as part of a healthy diet [42
] and have been associated with lower risk of diabetes and heart disease [157
]; however, this risk may be moderated by specific genes [159
] suggesting that in the future we may be able to predict who would or would not benefit from a high whole grain diet in terms of reducing risk for glucose intolerance, diabetes and obesity, a common co-morbid problem with MS. Grain free Paleo diets have been associated with greater insulin sensitivity and were more satiating per Calorie than a Mediterranean diet [160
Little is known about the impact of grains on MS or the role of a gluten-free diet. A 2019 systematic review concluded there is not enough evidence to determine the effect of gluten on MS [161
]. The ESPEN does not currently recommend a gluten-free diet for prevention of MS [92
]. Whole grains are good fiber sources which may be beneficial for MS [11
]. Higher fiber diets have been associated with lower weight, shifts in the microbiome [162
] and fewer inflammatory cytokines [163
]. A cross-sectional study of 6989 pwMS found individuals in the top quintile of whole grain intake had lower odds of severe disability than individuals in the lowest quintile [68
]. Additional research is needed.
Swank grain guidelines are consistent with the DGA [42
] in the recommendation to consume whole grain sources “as much as possible” [49
]. The four grain servings per day recommended on the Swank diet does not meet the recommended servings for the DGA HEP at ≥1600 kcals (6694 kJ) [138
Grains are typically avoided on a Paleo diet [149
] because they were believed to have not been consumed by our ancient ancestors [71
]. Grains are excluded on the WahlsElim diet because of their lectin content and association with neurological symptoms in genetically susceptible individuals; see Nightshades in Section 4.2
. Fruits and Vegetables. In addition, wheat, rye and barley contain gluten which can also be metabolized into a morphine-like compound [164
], gluten exorphins, which is associated with increased gastrointestinal symptoms and influence pain perception and behavior [164
]. Wheat along with milk and eggs is also a common food trigger to Eosinophilic Esophagitis [154
]. The exclusion of grains on the WahlsElim diet along with the limitation or restriction of other carbohydrate-containing food groups (e.g., legumes, dairy, added sugars, processed foods) produces a diet pattern that is lower in total carbohydrates, glycemic load and glycemic index compared to the standard American diet [70
Fat-free and low-fat dairy products are included in the DGA [42
]. Recommended amounts are three cup equivalents per day for the HEP at 1600–3200 kcals (6694–13,389 kJ) [138
]. Dairy foods are good sources of calcium, vitamin D, potassium and vitamin A; excluding these foods significantly impacts the adequacy of calcium, vitamin D, potassium and choline in the DGA diet pattern [165
]. Although fat-free and low-fat dairy products are recommended, some recent studies suggest that full fat dairy may have higher bioavailability of key nutrients, anti-inflammatory properties, have neutral effect on cardiovascular risk and that fermented dairy products such as yoghurt, kefir and cheese have a neutral or positive effect on cardiovascular risk [166
The role of dairy products in the development and treatment of MS is unclear [11
] and additional research is needed. Milk but not cheese consumption was associated with MS prevalence [171
]. A recent case control study of 113 pwMS and an equal number of healthy women found a reduced risk for MS with low-fat dairy consumption > five times per week [172
]. Two studies with conflicting results associating dairy with disease activity, quality of life or disability were limited by the inability to determine the type of dairy consumed [11
]. After assessing the limited and conflicting evidence related to dairy and MS, authors of one editorial recommended pwMS consume low fat dairy products because of the nutrient content of these foods, especially calcium, which may reduce risk for osteoporosis [173
One theory for the potential negative effect of milk in pwMS is allergic response. Milk allergy is the most frequent food allergy in children [174
]. Six percent of adults with seasonal allergy have IgG antibodies to milk [153
]. Cow’s milk formula is associated with higher rates of type 1 diabetes and insulin autoantibodies in infants at genetic risk for developing type 1 diabetes [175
]. Milk along with eggs and wheat are common food triggers to Eosinophilic Esophagitis [154
]. Casein, a milk protein, can be metabolized into Beta-casomorph-7, a morphine-like substance [176
] which is associated with increased gastrointestinal symptoms and slower cognitive processing speed [178
]. Antibodies for intestinal inflammation were elevated in schizophrenic patients compared to controls and positively correlated with IgG antibodies to the milk protein casein [179
]. Butyrophilin is a dairy compound structurally similar to a compound in the brain, myelin oligodendrocyte glycoprotein (MOG), which through molecular mimicry may lead to immune mediated damage to myelin and neurons thus increasing risk of MS, cerebellar ataxia and neuropsychiatric symptoms [180
]. However, in a case control study of 48 pwMS and 48 controls elevated levels of cow’s milk specific IgE antibodies were not observed [181
Swank recommends consumption of fat free/low fat dairy products to minimize saturated fat intake and this is consistent with the current DGA [42
]. However, the two servings per day of dairy products recommended on the Swank diet is less than the three cup recommendation for the HEP [138
] at ≥1600 kcals (6694 kJ).
Dairy is typically avoided on a Paleo diet [149
] and is also excluded on the WahlsElim diet, although clarified butter (ghee) is permitted because the milk solids have been removed. Dairy is avoided on the WahlsElim diet because of its potential for producing negative symptoms described above.
The DGA recommend use of oils that contain a greater proportion of monounsaturated and polyunsaturated fats than saturated fat and in amounts within an individual’s energy needs [42
]. Oils are good sources of essential fatty acids, vitamin E and energy for weight maintenance [42
]. Acceptable Macronutrient Distribution Range (AMDR) for total fat is 20–35% of energy [182
]. The DGA recommend <10% energy from saturated fat to reduce risk of cardiovascular disease; saturated and trans-
fatty acids have been associated with higher rates of cardiovascular disease, insulin resistance and obesity [183
] and should be avoided.
Various studies investigating the effect of fat on MS have been summarized [11
]. Based on all currently available evidence, the ESPEN recommends consuming foods lower in saturated and higher in polyunsaturated fat for prevention of MS but they do not recommend omega-3 supplements to prevent MS [92
]. The ESPEN does not recommend omega-3 supplements to reduce MS relapses but suggests supplemental omega-6 fatty acids may potentially be beneficial [92
]. Additional research is needed.
Saturated fats are inflammatory and may lead to gut dysbiosis [186
]. Saturated fats also increase translocation of endotoxin into blood stream of mice and humans but the addition of fiber reduces this effect [163
] and the addition of fish oil protects against the endotoxemia [187
]. Endotoxins increase activation of the innate immune system and increased inflammatory cytokines, which in theory may have an effect on MS related symptoms. Olive oil is beneficial for neuroprotection [188
]. Olive oil has 36 different phenols with health benefits. Hydroxytyrosol is the predominate phenol and has been the most studied. Hydroxytyrosol intake is associated with favorable changes in antioxidant enzyme activity and lower levels of nuclear factor kappa
-light-chain-enhancer of activated B
cells (NF-kappa B) activation [189
]. However, an Australian case-control study did not find any associations between total, saturated, monounsaturated, polyunsaturated, omega-6 or plant sources of omega-3 fat and risk of first demyelinating event; total omega-3 and omega-3 fat from fish were associated with reduced risk of first event, however, fat from dietary supplements were not included in the analysis [141
4.6.1. Total Fat
Total fat amounts on the Swank diet are reduced [23
] because of the restriction of saturated fat and recommendations for oil intake between 20 and 50 g per day; Swank estimated his patients consumed 25–29% of energy from total fat [23
]. Swank oil recommendations are similar to DGA HEP oil amounts for 1600–3200 kcal (6694–13,389 kJ) diets [138
]. In contrast, fat Calories on the WahlsElim diet are increased and could potentially be higher than the AMDR. The WahlsElim diet advises individuals to increase intake of healthy fats (i.e., non-trans
-fat) to provide adequate energy intake. The higher fat level is required to offset the moderate protein (meat and fish) intake and reduction in total carbohydrate intake from the elimination of grains and other carbohydrate sources like grains, dairy and added sugars.
4.6.2. Saturated and Trans Fatty Acids
The main goal of the Swank diet is to limit saturated fat intake to ≤15 g per day based on his epidemiological evidence that fat from meat and dairy was associated with MS incidence. Swank estimated his patients consumed 15–17% of energy from ‘fats’ (i.e., saturated fat) [23
]. This saturated fat estimate is higher than current recommendations; however, fat intake calculated with modern nutrient databases and dietary collection methods might yield different estimates. In contrast, Dr. Wahls does not restrict saturated fat intake unless it is clinically indicated. The WahlsElim diet recommends saturated animal fats (ghee, lard or duck fat) or coconut oil for cooking (frying) rather than unsaturated fats which may be damaged when heated. The WahlsElim diet includes fiber-rich fruits and vegetables and supplemental cod liver oil to help mitigate the potential negative effects of higher saturated fat intake described above. Both WahlsElim and Swank diets recommend avoiding trans-
fats and foods containing them because of the negative health associations.
4.6.3. Monounsaturated and Polyunsaturated Fatty Acids
The Swank diet encourages mono and polyunsaturated fat intake by the use of 20 to 50 g oil per day depending on energy needs. Unsaturated fats from high fat foods such as fatty fish, nuts, avocado and olives as well as oils and salad dressings count towards the daily allotment. Use of sunflower, olive, safflower, sesame, canola, cottonseed, linseed, soybean, peanut and flaxseed oils are recommended on this diet [49
The WahlsElim diet encourages use of avocado, olive, sesame and sunflower oils which are sources of monounsaturated fatty acids. Flax, walnut and hemp oils are also encouraged as a source of alpha-linolenic acid, an essential fatty acid, but amounts are limited to two tablespoons per day to maintain balance in omega 6:3 ratio. Higher alpha-linolenic acid intake was associated with reduced risk of MS in the Nurses’ Health Study II [192
]. Individuals are encouraged to use all these oils, especially olive oil, cold to reduce the damage to the polyphenols caused by heating [193
]. Heating olive oil to greater than 180 degrees Fahrenheit (82 degrees Celsius) is associated with 60% reduction of hydroxytyrosol content [193
]. Use of oils that are cold pressed and do not require solvent extraction such as olive oil, flax oil, hemp oil and walnut oil are also preferred for the WahlsElim diet.
Individuals consuming the WahlsElim diet are encouraged to reduce intake of vegetable oils and consume grass fed meats and wild caught fish according to their financial means which will shift the omega 6:omega 3 fatty acid ratio towards the more favorable ratio of 4:1 [195
]. Canola, corn and soybean oil are sources of omega-6 fatty acids and are to be avoided to maintain omega 6:3 ratio near 4:1 [195
]. Canola oil is processed using solvent for extraction of the oil and should also be avoided to decrease exposure to solvents [197
]. The omega 6:3 fatty acid ratio modulates neuronal membrane fluidity, neurotransmitter manufacturing and central nervous system inflammation.
4.8. Salt and Sodium
The DGA recommend limiting sodium (Na) intake to <2300 mg per day because of the association between increased intake and higher blood pressure [42
]. However, restricting salt intake for the purpose of improving MS disease course is controversial [201
] and more research is needed [204
]. Na intake, such as from salt, increases TH17 activity in animal models [205
] but data in humans are not as clear; Na intake in humans is not predictive of MS disease activity [208
]. Mechanisms of what appears to block the deleterious effect of Na on MS disease activity include potassium supplementation and higher dietary intakes from increased quantities of F/V and less processed food [209
]. Compounds that block inappropriate TH17 activity include curcumin [212
], vitamin D [217
] and sulforaphane (cabbage family vegetables) [218
Swank did not specifically recommend the use or restriction of salt or prescribe a Na intake in his book or the Swank MS Foundation website, however, cola soft drinks were restricted to 16 ounces (491 g)/day because of the Na content ([48
] p. 116). He provided recipes for herb mixtures that could be used as salt substitutes ([48
] p. 137) but also included salt in his recipes and high Na condiments such as soy sauce, suggesting Swank did not specifically restrict salt. However, the Na content of the diet may be lower than those of typical Americans due to the limited intake of commercial foods (see Section 4.11
. Processed Foods) which are significant contributors to Na intake [42
] and the elimination of salty meats such as bacon, ham, lunch meat, hot dogs and sausage due to their high fat content.
Salt is also not restricted on the WahlsElim diet. However, Paleo diets are typically lower in Na [70
] because they exclude commercially processed foods that are high in Na and avoid adding salt when preparing or eating food [71
]. In addition, Paleo diets tend to have a lower sodium:potassium ratio compared to typical American diets due to the lower Na level and the higher potassium intake from increased quantities of F/V [71
]. Individuals following the WahlsElim diet who are using table salt would be advised to purchase iodized table salt or iodized sea salt to minimize risk for iodine deficiency; see Section 4.12.1
. Seaweed and Algae.
According to the DGA, healthy adults can safely consume a moderate caffeine intake of three to five cups (720–1200 mL) coffee (400 mg caffeine) per day [42
]. This recommendation was based on data showing coffee intake was not associated with chronic diseases [42
]. Consuming three to four cups of coffee per day has been associated with decreased CVD risk [222
]. Moderate caffeine and coffee consumption also does not appear to increase risk of developing MS [223
] and may be associated lower risk of developing MS [224
]. In another study, caffeine intake was associated with lower disability and fatigue [225
]. Coffee may exert its protective effects in neurodegenerative diseases, including MS-related neurodegeneration, by blockade of adenosine receptors [226
]. There are no specific caffeine intake guidelines for pwMS.
Swank restricted caffeine intake (coffee, tea, cola soft drinks) to three cups per day because he observed that it contributed to anxiety and nervousness in some of his patients which could then exacerbate other MS-related symptoms and have a negative impact on personal relationships ([48
] p. 29). Swank’s caffeine restriction is consistent with DGA recommendations for healthy adults [42
]. The WahlsElim diet places no restriction on caffeine intake unless the patient has difficulty with sleep, in which case patients are advised to limit the number of cups and the timing of caffeinated beverages.