Objectives: To review the contribution of the Nurses' Health Study (NHS) to identifying the role of lifestyle, diet, and genetic or biological factors in several neurodegenerative diseases, including cognitive decline, multiple sclerosis, Parkinson's disease, and amyotrophic lateral sclerosis.
Methods: We completed a narrative review of the publications of the NHS and NHS II between 1976 and 2016.
Results: In primary findings for cognitive function, higher intake of nuts, moderate alcohol consumption, and higher physical activity levels were associated with better cognitive function. Flavonoids, physical activity, and postmenopausal hormone therapy were related to cognitive decline over 2 to 6 years. The NHS also has been integral in establishing Epstein-Barr virus infection, inadequate vitamin D nutrition, cigarette smoking, and obesity as risk factors for multiple sclerosis and inverse associations between cigarette smoking and caffeine and risk of Parkinson's disease. Increased risk of amyotrophic lateral sclerosis has been associated with cigarette smoking and decreased risk associated with obesity.
Conclusions: The NHS has provided invaluable resources on neurodegenerative diseases and contributed to their etiological understanding. We anticipate that the NHS cohorts will continue to make important contributions to the field of neurodegenerative diseases.