A review of ageing related biomarkers in breath

The growing ageing population presents significant challenges for healthcare systems, particularly in monitoring age-related physiological decline. Ageing is a complex, multifactorial process that manifests without specific symptoms and is shaped by lifestyle, environmental exposures, diet, and underlying health conditions. Identifying reliable biomarkers of ageing could enable early interventions, improve prognostic accuracy, and reduce healthcare burdens. One promising avenue is exhaled breath analysis, where volatile organic compounds (VOCs) offer a non-invasive window into physiological states. Breath VOC profiling shows promise in the detection of cancer and pulmonary diseases and is already used as a diagnostic tool for metabolic disorders and conditions such as asthma. This review examines 11 studies investigating age-dependent changes in exhaled breath VOCs, with attention to analytical methodologies, compound overlap, and mechanistic relevance. A search of four databases covering publications from 2000 to 2024 was conducted using keywords related to breath, VOCs, and ageing. Commonly reported age-associated VOCs included alkanes, isoprene, and acetone, though functional group trends varied across studies due to methodological differences. Several VOCs were linked to ageing-related pathways such as NF-κB, Nrf2-Keap1, and PI3K/Akt, suggesting potential mechanistic involvement beyond mere correlation. Although no consensus biomarker has yet emerged, the integration of advanced analytical platforms with AI-driven data interpretation holds promise for developing robust, breath-based diagnostics for ageing.