Dietary Fiber and Amyotrophic Lateral Sclerosis
Dietary Fiber and Amyotrophic Lateral Sclerosis
Amyotrophic lateral sclerosis (ALS) is a fast-progressing neurodegenerative disease with a median survival time from diagnosis of 1.5–3 years. The cause of ALS is unknown, but inflammation may play a role. Fiber has been shown to lower inflammatory markers, and a high fiber intake was associated with a lower risk of ALS in a case-control study; however, prospective studies are lacking. We explored the relation between dietary intake of fiber and the risk of ALS in 5 large prospective cohort studies comprising over 1,050,000 US citizens who contributed 1,133 ALS cases during a mean of 15 years of follow-up (1980–2008). Cox proportional hazards models were used within each cohort, and cohort-specific estimates were subsequently pooled using a random-effects model. We found that intakes of total fiber, cereal fiber, vegetable fiber, and fruit fiber were not associated with ALS risk when comparing the highest quintile of intake with the lowest (for total fiber, pooled multivariable relative risk (RR) = 0.99, 95% confidence interval (CI): 0.80, 1.24; for cereal fiber, RR = 1.13, 95% CI: 0.94, 1.37; for vegetable fiber, RR = 0.97, 95% CI: 0.77, 1.23; and for fruit fiber, RR = 1.05, 95% CI: 0.86, 1.29). These findings do not support the hypothesis that fiber intake is a major determinant of ALS risk.
Amyotrophic lateral sclerosis (ALS) is a fast-progressing neurodegenerative disease with a median survival time from diagnosis of 1.5–3 years. As of yet, little is known about the causes of ALS, but oxidative stress and inflammation are likely contributors to the neurodegenerative process.
We have previously reported that high intakes of nutrients with antioxidant or anti-inflammatory properties, including vitamin E and carotenoids, are associated with a lower ALS risk. Fiber is also a possible modifier of ALS risk because dietary fiber has been shown to lower concentrations of inflammatory markers, including C-reactive protein, tumor necrosis factor-α, and plasma interleukin-6, and to be associated with a lower risk of death from inflammatory diseases. An inverse association between dietary fiber intake and ALS risk was reported in a case-control study, but this association has not been examined in longitudinal studies. We therefore examined the relation between dietary fiber intake and ALS risk in 5 large prospective cohort studies with comprehensive food intake data, including over 1,050,000 men and women who contributed 1,133 cases of ALS during a mean follow-up of 15 years.
Abstract and Introduction
Abstract
Amyotrophic lateral sclerosis (ALS) is a fast-progressing neurodegenerative disease with a median survival time from diagnosis of 1.5–3 years. The cause of ALS is unknown, but inflammation may play a role. Fiber has been shown to lower inflammatory markers, and a high fiber intake was associated with a lower risk of ALS in a case-control study; however, prospective studies are lacking. We explored the relation between dietary intake of fiber and the risk of ALS in 5 large prospective cohort studies comprising over 1,050,000 US citizens who contributed 1,133 ALS cases during a mean of 15 years of follow-up (1980–2008). Cox proportional hazards models were used within each cohort, and cohort-specific estimates were subsequently pooled using a random-effects model. We found that intakes of total fiber, cereal fiber, vegetable fiber, and fruit fiber were not associated with ALS risk when comparing the highest quintile of intake with the lowest (for total fiber, pooled multivariable relative risk (RR) = 0.99, 95% confidence interval (CI): 0.80, 1.24; for cereal fiber, RR = 1.13, 95% CI: 0.94, 1.37; for vegetable fiber, RR = 0.97, 95% CI: 0.77, 1.23; and for fruit fiber, RR = 1.05, 95% CI: 0.86, 1.29). These findings do not support the hypothesis that fiber intake is a major determinant of ALS risk.
Introduction
Amyotrophic lateral sclerosis (ALS) is a fast-progressing neurodegenerative disease with a median survival time from diagnosis of 1.5–3 years. As of yet, little is known about the causes of ALS, but oxidative stress and inflammation are likely contributors to the neurodegenerative process.
We have previously reported that high intakes of nutrients with antioxidant or anti-inflammatory properties, including vitamin E and carotenoids, are associated with a lower ALS risk. Fiber is also a possible modifier of ALS risk because dietary fiber has been shown to lower concentrations of inflammatory markers, including C-reactive protein, tumor necrosis factor-α, and plasma interleukin-6, and to be associated with a lower risk of death from inflammatory diseases. An inverse association between dietary fiber intake and ALS risk was reported in a case-control study, but this association has not been examined in longitudinal studies. We therefore examined the relation between dietary fiber intake and ALS risk in 5 large prospective cohort studies with comprehensive food intake data, including over 1,050,000 men and women who contributed 1,133 cases of ALS during a mean follow-up of 15 years.
