Swank and Wahls Diets Found to Help with MS Fatigue, Quality of Life
The low-fat Swank diet and the Wahls elimination diet reduced fatigue and improved quality of life after three months for people with relapsing-remitting multiple sclerosis (RRMS), a clinical trial has found.
“It’s encouraging that fatigue was reduced and quality of life improved in both groups,” Bruce Bebo, PhD, from the National MS Society, which funded the study, said in a press release. “This well-conducted study shows that a healthy diet is one pathway to restoring function in people with MS.”
The study, “Impact of the Swank and Wahls elimination dietary interventions on fatigue and quality of life in relapsing-remitting multiple sclerosis: The WAVES randomized parallel-arm clinical trial,” was published in the journal Multiple Sclerosis Journal – Experimental, Translational and Clinical.
Fatigue is one of the most common symptoms of MS, affecting about 80% of patients. Defined by mental and/or physical exhaustion that prevents people from engaging in daily activities, fatigue is associated with increased disability and a reduced quality of life (QoL).
Although there is no definitive evidence supporting an MS-specific diet, preliminary studies suggest that certain diets may reduce fatigue in people with MS.
The Swank diet, proposed by Roy Swank, MD, PhD, restricts the intake of saturated and unsaturated fats and oils and emphasizes fruits and vegetables, nonfat dairy products, and whole-grain cereals. Clinical trials evaluating low-fat, plant-based diets have been shown to reduce fatigue and improve QoL in RRMS patients.
The Wahls elimination diet, a so-called modified Paleolithic diet developed by Terry Wahls, MD, cuts out highly processed foods, especially high carbohydrate foods, and encourages the intake of meats, fish, and plant-based foods, such as fruits, roots, and nuts. The diet also eliminates grains, dairy, legumes (such as soy), eggs, and nightshade vegetables such as tomatoes, potatoes, and peppers. Small clinical trials have also demonstrated the diet can help with fatigue and QoL for progressive MS and RRMS patients.
As surveys suggest these dietary modifications are popular among MS patients, a study (NCT02914964) was conducted by Wahls and researchers at the University of Iowa to investigate the impact of the two diets on fatigue.
“The objective of this study was to assess and compare the effect of the Swank and Wahls diets on perceived fatigue and QoL in individuals with RRMS,” the team wrote.
The study enrolled 87 adult RRMS patients who experienced fatigue. They were instructed to follow their typical diet for 12 weeks as a control period. Then, 43 participants were randomly assigned to the Wahls diet and 44 to the Swank diet for 24 weeks (about six months).
The primary outcome was the impact of each diet on the Fatigue Severity Scale, a patient-reported measure of fatigue in which higher scores reflect more fatigue, at 12 weeks (about three months). Physical function and QoL were also assessed.
A total of 77 participants completed the first 12 weeks of intervention, and adherence to the diets was generally high — 79.5% in the Swank group and 86.8% in the Wahls group. Of those, 72 completed the 24 weeks, and adherence remained high.
Results showed that both diets significantly reduced fatigue. With the Swank diet, fatigue scores dropped by 0.94 points at 12 weeks and by 1.01 points after 24 weeks. The Wahls diet group experienced 0.71 mean point reductions in fatigue after 12 weeks and 1.31 points after 24 weeks.
These findings were considered clinically meaningful due to a reduction greater than 0.45 points, “suggesting significant benefit of these two dietary interventions for MS-related fatigue,” the team wrote.
An additional fatigue measure, the Modified Fatigue Impact Scale, also showed a clinically meaningful reduction in fatigue for patients following either diet after 12 and 24 weeks. However, at 24 weeks, those in the Wahls group reported a significantly greater reduction in this score than the Swank group.
Assessment of mental and physical QoL, as tested by the Multiple Sclerosis Quality of Life-54 (MSQoL-54), also showed significant improvements in both groups. The Swank diet significantly improved mental health after 24 weeks, whereas the Wahls group showed a clinically meaningful difference at 12 and 24 weeks.
While the changes in the physical MSQoL-54 scores were also clinically meaningful for both diets after 12 and 24 weeks, the Wahls group improvements were again significantly greater than the Swank group.
There were no improvements in distance walked in six minutes — a measure of exercise capacity — in both groups after 12 weeks, but those that followed the Wahls diet achieved a clinically significant 6% increase in distance walked by 24 weeks. When participants who did not adhere to the diets were removed from the analysis, the 24-week mean difference in the distance walk significantly improved with both diets.
“It is possible that walking endurance takes longer to develop than participant-reported outcomes such as fatigue and QoL with dietary interventions,” the researchers wrote.
Following the Swank diet, 47.7% of participants reported meaningful improvements in mental QoL and 50.0% in physical QoL. In the Wahls group, 68.4% experienced an improvement in mental QoL and 60.5% in physical QoL. After adjusting for non-adherent participants, the mental QoL scores were higher in the Wahls group (74.2%) than the Swank group (45.5%) after 12 weeks, but not after 24 weeks.
“The observation that both dietary approaches in this study are associated with significant reductions in fatigue and improvements in QoL greatly benefits the MS community in that it allows for patient preference for either diet and suggests that the benefits of dietary approaches are due to underlying mechanisms rather than unique characteristics of specific diets,” the investigators wrote.
“The results from this study provide justification for future randomized controlled trials with larger sample sizes and longer duration to evaluate changes in brain MRI-evaluated disease activity and exploration of underlying mechanisms by which diet may affect the MS disease course,” they added.
The National MS Society recommends MS patients consult with their healthcare team before adopting any new diet. “Eating a restrictive diet may lead to vitamin or mineral deficiencies, which may impact overall health,” it stated.
“Be sure to get the full details about these diets and their recommended nutritional supplements so that you get the nutrition you need while you are trying one of these approaches,” the society added.