Heartbeat: bathing daily is associated with a lower cardiovascular risk

Lifestyle behaviours such as smoking, exercise and diet have received consideration attention as risk factors for cardiovascular disease (CVD) with lifestyle modification now serving as the foundation for primary prevention. Tub bathing is a potentially beneficial behaviour that has received less attention, possibly due to geographic and cultural variation in this behaviour. Japanese tub bathing, which typically involves sitting in hot water to shoulder depth, exposes the bather both to heat and to water pressure, which results in an increase in stroke volume and cardiac output with a reduction in systemic vascular resistance. Ukai and colleagues1 investigated the association between tub bathing and long-term CVD risk in a study of over 30 000 participants without CVD at baseline who were then followed for 20 years1 . On multivariable analysis, the risk of total CVD was lower in those who bathed almost daily or daily compared with those who bathed two or fewer times per week (HR 0.72, 95% CI 0.62 to 0.84, trend p<0.001) with similar trends for coronary artery disease and stroke risk (figure 1). Figure 1 Cumulative Kaplan-Meier curve for proportion of free from cardiovascular disease according to the frequency of tub bathing per week. In the accompanying editorial, Burden2 cautions that confounding variables may account for the observed associations, despite the author’s attempt to account for known differences between groups. In addition, the style of bathing in Japan, sitting with hot water to shoulder height, sadly is not available to most of us worldwide. Finally, the study …