In this article, we look at the history of the Swank diet, what it consists of, and the impact that diet might have on multiple sclerosis (MS).
History of the Swank diet
The Swank diet intends to ease the symptoms of MS through nutritional management.
Dr. Roy Swank began studying people with MS in Canada in the 1940s. He then traveled to Europe for further research and conducted a survey in Norway.
Based on the study results, he found that the prevalence of MS was higher in the mountains and lower in coastal fishing towns.
Dr. Swank then examined dietary differences between people living in the mountains and along the coast. He found that the people in the mountains consumed more meat, eggs, and dairy than those living near the coast, who, in turn, ate more fish.
Based on these findings, Dr. Swank worked with Aagot Grimsgard, a dietitian, to develop the low-fat diet now known as the Swank diet.
A main feature of the Swank diet is that it limits fat, especially saturated fat. People who follow the diet are encouraged to consume lean fish, non-fat dairy products, fruits, vegetables, and whole grains. Dr. Swank published a book on the diet in 1987.
What does it involve?
The main points of the Swank diet are described below:
The Swank diet focuses on limiting the amount of fat consumed, and focusing on wholegrain, vegetables, and lean meats.
- no more than 15 grams (g) of saturated fat per day
- no less than 20 g of unsaturated fat per day
- no more than 50 g of total fat per day
Plant oils, such as olive oil, canola oil, soybean oil, peanut oil, and flax oil are allowed on the Swank diet because they contain mostly unsaturated fat.
Coconut and palm oils are not recommended due to their high saturated fat content. Similarly, butter, lard, margarine, shortening, and hydrogenated oils are not allowed due to their high saturated or trans fat content.
Nuts, nut butter, and seeds are recommended as snacks, but they must be counted in the daily fat total.
Fruits and vegetables
All fruits and vegetables are allowed on the Swank diet, and the amounts are not restricted. People following the diet are encouraged to consume at least 2 servings each of fruits and vegetables per day.
Fruits that naturally contain fat, such as avocados and olives, must be counted towards the daily fat total.
Meats and poultry
Red meat and pork are banned during the first year of a person following the Swank diet. After that, they may eat 3 ounces of red meat once per week.
Skinless white chicken and turkey meat are allowed on the Swank diet. Dark meat poultry and processed poultry products are not recommended.
White fish and shellfish are allowed on the Swank diet. Portion sizes are not limited, except for shellfish in people with high cholesterol.
Fatty fish, such as salmon and tuna, must be included in the daily fat total.
Dairy and eggs
The Swank diet recommends 2 servings per day of non-fat or low-fat dairy products.
Servings of some dairy products, such as non-fat milk, non-fat cottage cheese, and fat-free cheese, are not restricted.
Due to the saturated fat content of egg yolks, Swank diet followers are limited to one whole egg no more than three times per week.
The Swank diet recommends people consume 4 servings of grain products per day. Breads, low-fat cereals, rice, pasta, and certain crackers are allowed. Wholegrain products are favored.
Baked goods that contain a fat source that should be avoided, such as butter or lard, are not recommended.
Caffeine and alcohol
Caffeinated beverages are limited to 3 cups per day while on the Swank diet. It also allows 1 serving per day of wine or liquor.
Specific vitamin and mineral supplements are recommended for those following the Swank diet. The suggested supplements include cod liver oil, a multivitamin with minerals, vitamin C, and vitamin E.
Evidence for use in MS management
Dr. Swank published multiple articles advocating the benefits of a low-fat diet for people with MS. He followed some of those from his original diet study for many years.
In 1990, he published a 34-year follow-up study on 144 people with MS. He reported that those who ate less than 20 g of saturated fat per day had less disease progression and were less likely to die than those who ate more saturated fat.
It is important to note that Dr. Swank's research is criticized for not having a control group to make comparisons with, and for lacking strict inclusion criteria. His study also had a high drop-out rate.
To expand on Dr. Swank's work, a study published in 2016 looked at how people with MS were affected by following the McDougall Program for 1 year. The McDougall Program is very low-fat, similarly to the Swank diet, but it also excludes meat, fish, eggs, dairy, and vegetable oils.
Study participants in the diet group did not see improvements in their brain scans or fewer symptom flares than those in the control group. They did, however, report improved energy levels, and they had positive changes in their BMIs.
Interestingly, cholesterol and insulin levels were lower in the diet group after 6 months, but not when the study ended.
The Swank diet is very restrictive and may be difficult for many people to follow over a long period.
People on a very low-fat diet, such as the Swank diet, may also experience drier skin and hair and have lower energy levels than other people.
Can a specific diet help with MS?
Currently, research is ongoing into what kinds of diets provide the most benefits for people with MS.
Nutrition is a form of complementary and alternative medicine commonly used by people with MS. A small survey completed in 2014 found that almost 30 percent of people with MS followed a special diet, as part of their treatment.
Currently, according to the National Multiple Sclerosis Society, there is not enough evidence to recommend one diet as best for people with MS.
Terry Wahls, a doctor, author, published researcher and a clinical professor of medicine with progressive MS herself, has developed the Wahls protocol. This emphasizes a Paleolithic style diet and excludes grains and gluten.
Research is expanding on a Paleolithic diet approach, but a 2017 study shows its promise as part of a complementary approach to MS management.
A 2009 study revealed that people who had MS had elevated levels of gluten antibodies compared to controls and recommended consideration of a gluten-free diet.
Despite the conflicting opinions about the role of grains and gluten, people with MS are encouraged to consume a healthful diet. Such a diet limits added sugar and processed foods and emphasizes fruits, vegetables, lean proteins, and healthful fats.
How might specialized nutrition help with symptoms?
Certain nutrients have been studied to see if they might help with MS symptoms.
MS and salt
The effect of dietary salt intake on MS has been studied in animals and humans.
In mice, dietary salt has been linked to increased inflammation of the nervous system and decreased immune system function. In people with MS, higher dietary salt intake has been linked to more brain scarring and more frequent symptom flares.
Further studies are needed before salt intake can definitively be linked to MS symptom severity.
MS and fish oil
A 2016 study found omega-3s originating from fish reduced MS diagnosis risk over a 12-month period. Other research suggests omega-3s may be more protective for men than women.
MS and vitamin D
Other, more extensive research published in 2017 revealed that high-dose vitamin D reduced a specific antibody level in relapsing-remitting MS.
Dietary dos and don'ts for multiple sclerosis
Some researchers report that high cholesterol, high blood pressure, heart disease, diabetes, and obesity may increase the rate of MS progression and severity. Therefore, it may be important for people with MS to follow an eating plan that helps them maintain a healthy weight.
Eating balanced meals regularly throughout the day can help people with MS keep their energy levels up. Keeping healthful food on hand that is also easy to prepare can be important, for those battling fatigue.
People with MS may experience bladder problems, but staying hydrated is important. Adequate fluid and fiber can help manage constipation, while foods to fight inflammation are also key.
One area of intense study involves gut bacteria, the gut-brain axis, and autoimmune and neurological diseases, such as MS. The bacterium Clostridium perfringens was found to be elevated in those with MS, while an imbalance of the Bacillus species and others were observed in a 2017 review.
Nutrition continues to be a hot topic in the research on MS treatment. Many specialist diets continue to be studied for their potential benefits.
People with MS looking to optimize their nutrition should seek the advice of a registered dietitian. A specialist of this kind can look at someone's medical history and lifestyle to help them find the best plan, strategy, or goals to use.