A recent study conducted by the University of Oulu has established a link between exposure to nighttime noise and alterations in blood cholesterol levels and lipid metabolites, which are recognized risk factors for cardiometabolic diseases. This research, part of the LongITools study and detailed in the journal Environmental Research, represents one of the most extensive investigations to date examining how prolonged exposure to traffic noise affects the body’s underlying biological processes.
Researchers observed quantifiable shifts in the blood’s lipid profile, including cholesterol-related indicators, among individuals exposed to road traffic noise at or above approximately 50 decibels (dB) during the night. These effects were found to intensify as noise levels increased.
Traffic noise constitutes an omnipresent yet frequently underestimated environmental exposure. Across Europe, millions are subjected to road traffic noise levels deemed detrimental to health, particularly during nighttime hours.
While prior studies have correlated road noise with cardiovascular ailments and diabetes, the exact biological pathway through which noise affects the body remained elusive. This current work helps bridge that gap by demonstrating that noise exposure is associated with metabolic process changes occurring well before the onset of diagnosable disease.
The scientists analyzed data from 272,229 adults aged 31 and older, drawn from three major European population cohorts: the UK Biobank, the Rotterdam Study, and the Northern Finland Birth Cohort of 1966.
Individual residential addresses were used to model nighttime road traffic noise exposure via existing national noise maps. The analysis specifically prioritized nighttime levels, as this is when people are typically at home and most susceptible to sleep disturbances.
Blood samples were evaluated using an advanced Nuclear Magnetic Resonance (NMR)-based metabolomics platform, allowing for the quantification of 155 distinct metabolic biomarkers.
This methodology enabled the researchers to connect prolonged nighttime noise exposure with detailed metabolic variations present in the blood.
The study revealed that exposure to nighttime road traffic noise exceeding 55 dB correlated with elevated concentrations of total cholesterol, LDL (“bad”) cholesterol, cholesterol-enriched esterified lipoproteins, free fatty acids, and membrane lipids—all substances critically involved in cardiometabolic health. A clear “dose-response” relationship was evident for most biomarkers, with metabolic alterations becoming noticeable starting at the 50 dB noise threshold.
“Our findings suggest that road traffic noise at night can subtly yet persistently impact metabolic health,” comments study co-author Yihan He from the University of Oulu. “Although the cholesterol and lipid level changes in any single person may seem minor, the sheer number of people exposed to road traffic noise means the potential public health impact could be substantial.”
“This research offers biological evidence supporting the previously observed link between transportation noise and cardiometabolic diseases. It reinforces the notion that environmental noise is not merely an annoyance but a genuine health concern,” adds study co-author Professor Sylvain Sebert, also from the University of Oulu. “Reducing exposure to road traffic noise at night may help mitigate potential consequences for metabolic health. Our results endorse the effectiveness of policies and measures, including urban planning strategies aimed at lowering traffic noise levels in residential areas and designing buildings that prioritize quieter sleeping environments.”
This investigation adds to the growing body of evidence indicating that safeguarding individuals from excessive noise exposure, especially overnight, can contribute to the preservation of long-term cardiometabolic well-being.
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