Regimen that boosted carbohydrate intake seemed to work best, researchers say, but more study needed
By Steven Reinberg
THURSDAY, Feb. 27, 2014 (HealthDay News) -- There's early evidence from a small study that people with amyotrophic lateral sclerosis -- also known as ALS or Lou Gehrig's disease -- who are fed a high-calorie, high-carb diet, may see the progression of their disease slowed.
ALS is a degenerative disease that kills nerve cells, leading to weakness, paralysis and usually death from respiratory failure. As the disease progresses, patients often lose a significant amount of weight.
Patients with ALS who have difficulty swallowing, as did the 24 in this study, often end up needing a feeding tube into the stomach to get enough to eat. These patients are usually fed a standard commercially available formula.
"Giving your patients more energy [calories] than they necessarily need or are burning could help them prevent disease progression, and it might actually help improve their survival," said lead researcher Dr. Anne-Marie Wills, an assistant professor of neurology at Harvard Medical School.
Wills explained that ALS patients lose weight in part because they are not able to take in enough calories due to their difficulty swallowing. "As they lose weight they are actually burning their own muscle," she said.
In the study, researchers found that a high-calorie, high-carb tube-fed diet was safe and tolerated -- better than one designed to maintain weight or a diet high in fat, Wills said.
Moreover, patients on the high-calorie, high-carb diet gained some of the weight they had lost, she said.
At the very least, patients should avoid losing weight, Wills added. "We need larger trials to see if patients should be trying to gain weight, but until that happens, I think all ALS patients should try aggressively to avoid weight loss," she said.
The report was published in the Feb. 28 online edition of The Lancet.
Several experts noted that the results are far from definitive.
Dr. Ammar Al-Chalabi, a professor of neurology and complex disease genetics at King's College London, and author of an accompanying journal editorial, said, "This study is too small to really show a survival benefit of any of the diets."
To really know if there is a benefit, a larger trial is needed, but such a study is fraught with problems, Al-Chalabi said. One concern is that given the results of this preliminary study, patients may decide to try a high-calorie, high-carbohydrate diet on their own.
"Anyone with ALS will do a simple cost-benefit analysis: 'What is the cost to changing my diet? -- almost nothing. What is the benefit? -- possibly a better outcome,' " he said. "We may never know if these diets really work, what the diet change should be, and when it should be changed, if at all," Al-Chalabi said.
Dr. Zianka Fallil, a neurologist at the Cushing Neuroscience Institute in Manhasset, N.Y., agreed that the study was too small to make conclusions.
"The study would be more credible if it had more patients," she said.
For the study, Wills and colleagues recruited 24 ALS patients who had lost a lot of weight and were being fed through a tube placed directly into the stomach.
Patients were assigned to one of three groups. One group was fed enough to maintain their current weight, a second group was fed a formula high in fat, and the third group a formula high in carbs. Both of the latter groups were fed more calories than needed to maintain their weight.
The high-carb, high-calorie diet consisted of a commercial tube-feeding formula called Jevity 1.5, which contains 150 percent of the calories needed to maintain weight, Wills said. The high-fat diet consisted of a formula called Oxepa. Those on the weight-maintenance diet were given Jevity 1.0.
Over four months, patients kept track of their weight as well as how much they took in through their feeding tube and anything they were able to eat by mouth. During that time, one patient on the high-fat diet and six in the weight-maintenance diet dropped out of the study. But none of those on the high-carbohydrate diet did so.
The researchers found that patients on the high-carbohydrate formula gained a modest amount of weight, patients on the high-fat diet lost weight and the others maintained their weight.
Over five months of follow-up, none of the patients on the high-carbohydrate diet died. One in the high-fat group and three in the weight maintenance group died. All the deaths were from respiratory failure.
Those on the high-carbohydrate diet also saw a slowing of the progression of the disease compared to the weight-maintenance group, although the difference was not significant, the researchers noted.
Nina Eng, chief clinical dietitian at Plainview Hospital, in New York, explained that standard equations are used to figure out how much to feed an ALS patient based on energy needs.
"I wouldn't take this study and start feeding all patients with ALS a high-calorie diet -- you need more information," she said. "We don't know if it's helpful to give every patient with ALS a high-calorie, high-carbohydrate diet. Common practice is to use these equations to meet their needs."
To learn more about ALS, visit the U.S. National Institute of Neurological Disorders and Stroke.
SOURCES: Anne-Marie Wills, M.D., assistant professor of neurology, Harvard Medical School, and internist, Massachusetts General Hospital, Boston; Ammar Al-Chalabi, M.B., Ph.D., professor of neurology and complex disease genetics, King's College London, England; Nina Eng, chief clinical dietitian, Plainview Hospital, Plainview, N.Y.; Zianka Fallil, M.D., neurologist, Cushing Neuroscience Institute, Manhasset, N.Y.; Feb. 28, 2014, The Lancet, online
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