ABSTRACT Objectives The effect of environmental and lifestyle factors on patients with LRRK2 (leucine‐rich repeat kinase 2) p.Gly2019Ser (LRRK2 + /PD + ) compared to idiopathic PD (iPD) has yet to be thoroughly investigated. Methods In a homogeneous Tunisian Arab Berber population, we recruited 200 idiopathic PD and 199 LRRK2 p.Gly2019Ser mutation carriers, of whom 142 had PD (LRRK2 + /PD + ) and 57 were unaffected (LRRK2 + /PD − ). Case report form (CRF) questionnaires (motor and non‐motor symptoms) including the Geoparkinson Questionnaire were used to assess environmental and lifestyle factors. Results In LRRK2 + /PD + , tobacco use was significantly associated with a later median age at onset (AAO). The median AAO was 60 years (interquartile range = 52–67.25) for tobacco users, compared to 52 years (interquartile range = 45.25–61) for non‐users ( P = 0.0042 at adjusted α = 0.025). Additionally, we observed an independent but additive effect of black tea consumption and tobacco use. Conclusions Our data suggest that tobacco and black tea have a protective effect on age at onset in LRRK2 + /PD + . © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.