Diet and amyotrophic lateral sclerosis

Background: Several dietary factors have been associated with risk of amyotrophic lateral sclerosis (ALS) in case-control studies, but no prospective studies have investigated diet and ALS. Methods: We prospectively assessed the association of selected foods and beverages with ALS mortality among participants of the Cancer Prevention Study 11, a cohort of over 1 million men and women enrolled in 1982. Habitual diet was assessed with a 44-item food frequency questionnaire. Participant follow-up was conducted from 1989 through 2002 for ALS mortality. Results: During the follow-up period, 862 cohort participants died of ALS. The strongest finding was an inverse association between chicken consumption and risk of ALS (P for trend = 0.0006). We also observed an increased risk of ALS among study participants with a high consumption of brown rice/whole wheat/barley (P for trend = 0.006) and decaffeinated coffee (P for trend = 0.01), and a decreased risk of ALS for high consumption of tea (P for trend 0.02) and French fries (P for trend = 0.02); however, none of these latter associations remained significant after adjusting for multiple comparisons. Conclusions: Overall, these results do not provide convincing evidence that the investigated food items are related to ALS mortality. The association observed between chicken consumption and ALS mortality should be assessed in other studies.