Cold water exposure therapy and effects on insulin: a scoping review.

CONTEXT: Cold water exposure (CWE) is a growing trend among health and wellness communities due to its effects on brown adipose tissue (BAT) activation and neurotransmitter modulation. However, its impact on insulin sensitivity and glucose metabolism in humans remains underexplored. OBJECTIVES: This scoping review aims to evaluate the existing literature on the effects of CWE on insulin-related metabolic markers in humans and to identify the knowledge gaps that currently exist in this field of study. METHODS: A scoping review was conducted by two authors (JG and BM) according to the Joanna Briggs Institute (JBI) guidelines and framework. A systematic search of PubMed, Embase, and Cochrane databases was conducted on July 11, 2025, utilizing search strings developed by a trained librarian. Title and abstract screening, as well as full-text review and data extraction, were performed in a masked, duplicative fashion. Inclusion criteria required human studies published in English from 2000 onward that utilized CWE and measured insulin, glucose, or related metabolic outcomes. RESULTS: A total of 941 articles were identified, with 67 articles selected for further review. Ultimately, six studies met our inclusion criteria. These studies varied in participant demographics (male, female, mixed cohorts) and age groups ranging from 18 to 55+. The intervention duration included mostly acute sessions. The majority of studies (n=4) reported an improvement in insulin sensitivity and glucose utilization by peripheral tissues, as well as BAT utilization. However, the study by Sellers suggested increased insulin resistance, and the study by Hanssen et al. showed a decrease in cold-stimulated BAT glucose uptake. Only two studies utilized full-body CWE, whereas the remainder utilized cold suits or partial immersion techniques. CONCLUSIONS: Current research suggests that non-shivering-inducing CWE can enhance insulin sensitivity and glucose metabolism in healthy humans. Extrapolating these findings to suggest application as an adjunct therapy for insulin resistance is premature. However, methodological variability and a lack of high-quality, long-duration studies highlight the need for further research, particularly distinguishing between cold suits and full-body-immersion protocols, to clarify their efficacy and clinical applicability.