Milk intake and risk of neurodegenerative diseases

Milk intake has been associated with risk of neurodegenerative diseases in observational studies. Nevertheless, whether the association is causal remains unknown. In a new study published in Nutrients the authors adopted Mendelian randomization design to evaluate the potential causal association between milk intake and common neurodegenerative diseases, including multiple sclerosis (MS), Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), and Parkinson's disease (PD).

Genetic associations for neurodegenerative diseases were obtained from the International Multiple Sclerosis Genetics Consortium (n = 80,094), FinnGen consortium (n = 176,899), AD GWAS (n = 63,926), Web-Based Study of Parkinson's Disease (n = 308,518), PDGene (n = 108,990), and ALS GWAS (n = 80,610).

Lactase persistence variant rs4988235 (LCT-13910 C > T) was used as the instrumental variable for milk intake.

Their results suggest that genetically predicted milk intake is associated with a decreased risk of MS and AD but with an increased risk of PD. Further investigations are needed to clarify the underlying mechanisms.