Dietary habits and olfactory function in individuals with Parkinson's disease: an underexplored association

Parkinson's disease (PD) is a progressive neurological disorder characterized by motor and non-motor symptoms, including olfactory dysfunction, which may precede motor manifestations by up to 10-20 years. Given the role of olfaction in flavor perception and dietary behavior, olfactory impairment may significantly affect nutritional status and quality of life in individuals with PD. This opinion article discusses the relationship between olfactory dysfunction and dietary habits in PD, highlighting the scarcity and inconsistency of the available evidence. While some studies suggest that lower diet quality and reduced intake of specific nutrients are associated with worse olfactory performance, others found no significant correlations. We argue that these inconsistencies largely reflect methodological limitations. Future studies should adopt supervised data collection, validated olfactory tests, and culturally adapted dietary tools. Clarifying whether specific dietary patterns influence olfactory performance or whether olfactory impairment drives inappropriate eating behaviors is essential for better understanding disease progression and informing clinical strategies aimed at improving symptoms, nutritional status, and quality of life in people living with PD.