Results from a small study suggest that a high-calorie, high-carbohydrate diet may be a safe, simple treatment for amyotrophic lateral sclerosis (ALS), a progressive neurological disorder commonly known as Lou Gehrig disease.
Amyotrophic lateral sclerosis destroys nerve cells in the brain, leading to weakness, paralysis, and often death from respiratory failure. Because patients with the disease experience muscle atrophy and find it physically difficult to consume enough calories to maintain weight, they usually have substantial weight loss.
However, previous studies have shown that moderately obese patients with ALS lived longer and their disease progressed more slowly than underweight patients. Studies in a mouse model of ALS also linked a calorie-dense, high-fat diet with weight gain and delayed disease progression.
Reporting online in The Lancet, a team of US researchers randomly assigned 20 patients with advanced ALS to 1 of 3 diet groups: a weight maintenance group, a high-calorie, high-fat group, or a high-calorie, high-carbohydrate group. The patients already were receiving nutrition through feeding tubes and, on average, had lost about 20% of their body weight.
After 4 months on their assigned diet, patients were followed-up for 5 months primarily to evaluate the diets’ safety and tolerability. Those on the high-calorie, high-carbohydrate diet had the fewest adverse events: 23 adverse events among 8 patients compared with 42 among 6 patients in the weight maintenance group and 48 adverse events among 6 patients in the high-calorie, high-fat group. Gastrointestinal complications were the most common adverse events, and they occurred least often with the high-calorie, high-carbohydrate diet and most often with the high-calorie, high-fat diet.
Patients in the high-calorie, high-carbohydrate group gained about 1 pound per month, the weight maintenance group gained about one-quarter of a pound monthly, and the high-calorie, high-fat group lost about 1 pound per month even though their diet provided about 150% of the calories needed to keep their weight steady. Complications from weight gain, such as diabetes or heart disease, did not occur.
Four patients died during the first 4 months of the study—3 in the weight maintenance group and 1 in the high-calorie, high-fat group. The investigators reported that respiratory failure caused all the deaths and that mortality wasn’t related to the study diet. No deaths were reported in the high-calorie, high-carbohydrate group.
“This pilot study demonstrates the safety of a novel, simple, low-cost treatment for a devastating disease where currently, very few treatment options are available,” lead author Anne-Marie Wills, MD, of Massachusetts General Hospital in Boston, said in a statement. The sole drug approved by the US Food and Drug Association for patients with ALS is riluzole, which provides only a small survival benefit.
“The survival component of this study is the crucial issue,” Ammar Al-Chalabi, MD, PhD, of King’s College in London, England, wrote in an accompanying editorial. He noted that the ease and apparent safety of changing to a high-calorie, high-carbohydrate diet “might be regarded as sufficient evidence to change to such a diet.” However, Al-Chalabi also wrote that he won’t change practice with his own patients without results from larger studies.