In recent years, the quest to identify reliable biomarkers of aging has accelerated, aiming to illuminate the biological underpinnings of aging and to provide tools for early detection of functional decline. Among various candidates, taurine, a conditionally essential amino acid known for its multifaceted physiological roles, has recently drawn considerable attention. However, groundbreaking research conducted by scientists at the National Institutes of Health (NIH) challenges the prevailing notion that taurine serves as a universal biomarker for aging. Through meticulous longitudinal and cross-species analyses, this comprehensive study reveals that circulating taurine levels exhibit complex and inconsistent patterns with age, debunking earlier assumptions and urging a re-evaluation of taurine’s role in aging biology.
Taurine, a sulfur-containing amino acid, plays a pivotal role in processes such as bile acid conjugation, osmoregulation, antioxidation, and modulation of calcium signaling. Its importance is underscored in various tissues, including the cardiovascular system, skeletal muscle, and nervous system. Prior investigations, primarily in model organisms like worms and mice, have demonstrated that taurine supplementation can alleviate multiple age-associated phenotypes, promoting lifespan extension and functional improvements. This preclinical evidence propelled taurine into the spotlight as a potential biomarker and therapeutic target. Nonetheless, the translational relevance of these findings to humans had remained unverified until now.
The NIH-led study employed a robust experimental framework, leveraging longitudinal blood samples collected from diverse species, including humans, rhesus monkeys, and mice, encompassing a wide age spectrum. Specifically, the Baltimore Longitudinal Study of Aging (BLSA), the longest continuously conducted human aging study, provided human samples ranging from 26 to 100 years of age. Complementary cross-sectional cohorts from geographically distinct human populations—such as the Balearic Islands Study of Aging and the Predictive Medicine Research cohort from Atlanta—augmented the dataset, ensuring comprehensive demographic coverage and enabling cross-validation.
Contrary to prior expectations, the data illustrated that circulating taurine concentrations generally increased or remained stable with advancing age across humans, monkeys, and most murine subgroups. Intriguingly, male mice presented an exception, exhibiting steady taurine levels independent of age. These findings underscore species- and sex-specific nuances, emphasizing that taurine dynamics during aging are not monolithic but are shaped by complex biological determinants.
A pivotal revelation emerged from the longitudinal analyses within individual subjects. Variability in taurine concentrations within the same individual over time often exceeded the magnitude of age-related changes observed across populations. This finding indicates a substantial degree of intra-individual fluctuation, reflecting influences beyond chronological aging, likely encompassing genetic predispositions, dietary habits, environmental exposures, and physiological states. Such variability challenges the premise of taurine as a stable, universal biomarker for biological aging.
Moreover, the study probed the associations between circulating taurine levels and critical health parameters, including muscle strength and body weight—key indicators of functional status in aging populations. Results revealed inconsistent correlations; in some cases, both high and low taurine levels corresponded with diminished motor function, while in others, no association was evident. These discrepancies illuminate the complex interplay between taurine metabolism and physiological outcomes, further complicating the biomarker candidacy of taurine.
The cross-species comparative approach adopted in this research represents a significant advancement, helping to contextualize species-specific aging trajectories within a unified analytical framework. The observed heterogeneity in taurine dynamics underscores that aging biomarkers cannot be presumed to transcend biological boundaries without careful empirical verification. This insight carries profound implications for aging research, guiding future biomarker discovery efforts towards more nuanced and integrative methodologies.
The implications of this study extend to the burgeoning market of dietary supplements where taurine has gained popularity, fueled by preliminary studies suggesting benefits in aging mitigation. While animal models have yielded promising results, the absence of rigorous clinical evidence supporting the efficacy of taurine supplementation in humans remains a critical gap. This NIH investigation cautions against premature clinical adoption of taurine supplements based solely on model organism data, advocating for methodical human trials to elucidate its potential benefits or risks.
Dr. Rafael de Cabo, co-author and chief of the Translational Gerontology Branch at NIH’s National Institute on Aging, remarked on the impetus for this research, triggered by recent reports highlighting taurine’s intriguing biological effects. The study reflects a rigorous scientific endeavor to distinguish correlation from causation and to clarify taurine’s precise role against the backdrop of aging biology.
Dr. Maria Emilia Fernandez, a postdoctoral fellow and study co-author, emphasized the methodological strength and significance of integrating longitudinal data across multiple species. This approach enables dissection of the temporal dynamics and inter-individual variability often obscured in single timepoint cross-sectional studies. The results challenge the field to reconsider simplistic biomarker models and to embrace complexity inherent in biological aging.
In the broader context of aging research, reliable biomarkers remain elusive but are desperately needed to facilitate early interventions, monitor therapeutic efficacy, and personalize health strategies for aging populations. Dr. Luigi Ferrucci, scientific director at NIA and co-author of the study, highlighted the transformative potential of such biomarkers in extending healthspan and maintaining independence among the elderly. Although taurine may not fulfill this role, elucidating its limitations represents a critical step in refining the biomarker landscape.
This comprehensive investigation was supported by the NIH’s in-house research program at the National Institute on Aging, underscoring the agency’s commitment to unraveling complex biological aging processes through cutting-edge integrative research. Published in the prestigious journal Science, the full article presents rigorous data analysis and comprehensive discussion, providing an essential resource for researchers endeavoring to dissect the molecular and physiological facets of aging.
As the aging population worldwide continues to grow, the need for dependable biomarkers that can accurately capture biological aging processes intensifies. The findings from this extensive NIH study spotlight the challenges inherent in biomarker discovery and reinforce the necessity of multidimensional, longitudinal, and cross-species analyses to inform translational applications. Taurine’s story exemplifies the scientific process—initial promise, rigorous testing, and nuanced understanding—paving the way for future breakthroughs in aging biology.
Subject of Research: Aging biomarkers, taurine, longitudinal studies, cross-species analysis, aging biology
Article Title: Is taurine an aging biomarker?
News Publication Date: 5-Jun-2025
Web References:
https://www.science.org/doi/10.1126/science.adl2116
References:
R. de Cabo, M. E. Fernandez, et al. Is taurine an aging biomarker? Science. 2025. DOI: 10.1126/science.adl2116.
Keywords:
Health and medicine, Aging populations, Biomarkers, Longitudinal studies
