High-carbohydrate diet may help normalize SMA metabolism
Metabolic changes seen in SMA, ALS
A study found that people with spinal muscular atrophy (SMA) have metabolic alterations due to impairments in how their bodies use fatty acids for energy. The results suggested a carbohydrate-rich diet may help normalize metabolism in SMA patients.
The study, “Alterations of Fat and Ketone Body Metabolism in ALS and SMA—A Prospective Observational Study,” was published in the European Journal of Neurology.
SMA is a genetic disorder marked by the degeneration and death of motor neurons, the specialized nerve cells that control movements.
Research has suggested SMA and amyotrophic lateral sclerosis (ALS), another disorder characterized by motor neuron death and dysfunction, are marked by changes in metabolism, or how the body breaks down nutrients and produces energy. These metabolic changes may play a role in disease progression. Although the underlying disease causes are different, ALS and SMA have similar symptoms, including muscle wasting and weakness.
Aiming to further investigate how motor neuron disorders impact metabolism, scientists in Germany analyzed blood and urine samples from 77 people with SMA, 112 people with ALS, and 50 people with neither disease. The researchers were especially interested in how SMA and ALS affect how the body uses fat molecules for energy.
Free fatty acids higher in SMA
The scientists said they wanted to look at metabolic changes in the two diseases “to identify possible biomarkers as well as therapeutic nutritional targets.”
The researchers found that people with SMA had significantly higher levels of free fatty acids, fat molecules that can be burned for energy, than either ALS patients or controls. SMA and ALS patients also had elevated levels of ketone bodies, molecules produced as a byproduct of breaking down fats for energy.
People with more severe forms of SMA tended to have especially high ketone body levels, as patients with SMA type 2 had higher blood levels of ketone bodies and free fatty acids than those with SMA type 3, the researchers noted.
The scientists found that people with SMA or ALS who had a higher body mass index (BMI, a measure of body fat based on height and weight) tended to have higher levels of free fatty acids and ketone bodies. But for people without motor neuron disorders, higher BMI was associated with lower levels of free fatty acids and ketone bodies.
“In SMA … the persistence of ketogenesis [production of ketone bodies] may indicate an upregulation of all available metabolic pathways for energy production due to the disturbance of fatty acid utilization,” the scientists wrote.
This implies that a diet that’s rich in carbohydrates might help to normalize metabolism for people with SMA, the researchers said, though they cautioned that clinical trials will be needed to test the idea.
“Based on our results, the administration of a carbohydrate-rich diet might constitute a promising approach to bypass the defective fatty acid metabolism [in SMA],” the researchers wrote.
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