Patients diagnosed with amyotrophic lateral sclerosis (ALS) who didn’t yet have symptoms consumed more calories but had a lower body-mass index (BMI), according to a study published August 17, 2015 online in JAMA Neurology.
The results also showed that higher premorbid intake of total fat, saturated fat, trans-fatty acids, and cholesterol were associated with an increased risk of ALS, while higher alcohol intake was associated with a decreased risk.
“The combination of a positive association of high total energy intake, low premorbid BMI, and high fat intake, corrected for lifetime physical activity, supports a role for an altered energy metabolism before clinical onset of ALS,” the authors concluded.
The cause of ALS is poorly understood, but some evidence suggests that diet and nutrients might be involved in its pathogenesis. So, Jan H. Veldink, MD, PhD, of the University Medical Centre Utrecht, the Netherlands, and colleagues used a 199-item food frequency questionnaire to systematically determine the association between premorbid dietary intake and the risk of ALS. Their study, conducted from 2006 to September 2011, included 674 patients newly diagnosed with ALS and 2,093 control patients without ALS.
After analyzing the data and correcting for confounders, the authors determined that presymptomatic total calorie intake was higher in patients with ALS (average 2,258 kcal/day) compared with individuals in the control group (average 2,119 kcal/day). But presymptomatic BMI was lower in patients than in controls (25.7 vs. 26). No significant associations between dietary intake and survival were found.
“Our finding that presymptomatic daily energy intake in patients was higher and presymptomatic BMI was lower, which has also been demonstrated in large cohort and case-control studies, supports the hypothesis that energy expenditure is increased in patients with presymptomatic ALS,” the authors concluded.
The finding that higher alcohol intake was also associated with a decreased risk of ALS may have several possible explanations, the authors added. One such possibility could be the protective effect of antioxidants in red wine—although that doesn’t fully explain this particular finding, the authors acknowledged.