Dairy Intake and Parkinson's Disease: A Mendelian Randomization Study
Authors
Cloé Domenighetti ; Pierre-Emmanuel Sugier ; Ashwin Ashok Kumar Sreelatha ; Claudia Schulte ; Sandeep Grover ; Océane Mohamed ; Berta Portugal ; Patrick May ; Dheeraj R Bobbili ; Milena Radivojkov-Blagojevic ; Peter Lichtner ; Andrew B Singleton ; Dena G Hernandez ; Connor Edsall ; George D Mellick ; Alexander Zimprich ; Walter Pirker ; Ekaterina Rogaeva ; Anthony E Lang ; Sulev Koks ; Pille Taba ; Suzanne Lesage ; Alexis Brice ; Jean-Christophe Corvol ; Marie-Christine Chartier-Harlin ; Eugénie Mutez ; Kathrin Brockmann ; Angela B Deutschländer ; Georges M Hadjigeorgiou ; Efthimos Dardiotis ; Leonidas Stefanis ; Athina Maria Simitsi ; Enza Maria Valente ; Simona Petrucci ; Stefano Duga ; Letizia Straniero ; Anna Zecchinelli ; Gianni Pezzoli ; Laura Brighina ; Carlo Ferrarese ; Grazia Annesi ; Andrea Quattrone ; Monica Gagliardi ; Hirotaka Matsuo ; Yusuke Kawamura ; Nobutaka Hattori ; Kenya Nishioka ; Sun Ju Chung ; Yun Joong Kim ; Pierre Kolber ; Bart P C van de Warrenburg ; Bastiaan R Bloem ; Jan Aasly ; Mathias Toft ; Lasse Pihlstrøm ; Leonor Correia Guedes ; Joaquim J Ferreira ; Soraya Bardien ; Jonathan Carr ; Eduardo Tolosa ; Mario Ezquerra ; Pau Pastor ; Monica Diez-Fairen ; Karin Wirdefeldt ; Nancy L Pedersen ; Caroline Ran ; Andrea C Belin ; Andreas Puschmann ; Clara Hellberg ; Carl E Clarke ; Karen E Morrison ; Manuela Tan ; Dimitri Krainc ; Lena F Burbulla ; Matt J Farrer ; Rejko Krüger ; Thomas Gasser ; Manu Sharma ; Alexis Elbaz
Background: Previous prospective studies highlighted dairy intake as a risk factor for Parkinson's disease (PD), particularly in men. It is unclear whether this association is causal or explained by reverse causation or confounding.
Objective: The aim is to examine the association between genetically predicted dairy intake and PD using two-sample Mendelian randomization (MR).
Methods: We genotyped a well-established instrumental variable for dairy intake located in the lactase gene (rs4988235) within the Courage-PD consortium (23 studies; 9823 patients and 8376 controls of European ancestry).
Results: Based on a dominant model, there was an association between genetic predisposition toward higher dairy intake and PD (odds ratio [OR] per one serving per day = 1.70, 95% confidence interval = 1.12-2.60, P = 0.013) that was restricted to men (OR = 2.50 [1.37-4.56], P = 0.003; P-difference with women = 0.029).