Take a bath instead of only a shower, if you can

High value
Evidence B
Buys life
Disputed
Costs a little
Takes some hours
No willpower

In plain words

People who take a bath almost every day have about a 28% lower risk of a cardiovascular event, and about 46% lower risk of a brain hemorrhage, than people who bathe less than twice a week.

Cost: A bit more for water and electricity. Half an hour each time.
What you get: A Japanese study of 30,000 (3.0万) people followed for 19 years, with 2097 cardiovascular events. People who bathed almost every day had about 28% lower risk of a cardiovascular event than people who bathed no more than twice a week (hazard ratio 0.72, 95% CI 0.62–0.84, the plausible range). Coronary heart disease was about 35% lower (0.65, 0.45–0.94). Stroke was about 26% lower (0.74, 0.62–0.87). Brain hemorrhage was about 46% lower (0.54, 0.40–0.73)
Notes: The dispute is that this result comes from a Japanese population and bathtub culture, and most households in China are not set up for daily baths. Also, the water should not be too hot, and you shouldn't soak too long. For older people and people with heart or brain blood vessel disease, water that is too hot and soaks that are too long are actually dangerous, and every year a large number of older people in Japan die suddenly in the bathtub
Evidence grade: B : Supported by research but without a precise number, or based on small or single studies.
Sources: Ukai T, Iso H, Yamagishi K, et al. (2020). Habitual tub bathing and risks of incident coronary heart disease and stroke. Heart, 106(10), 732-737. https://doi.org/10.1136/heartjnl-2019-315752

Translated from the Chinese original. Original book, section 2, tip 36. This section is about health and medicines. It is general information, not a substitute for a doctor’s diagnosis or prescription. Content may be out of date and rules differ by place. When you actually deal with an agency, a doctor or a court, follow what local officials, doctors and lawyers tell you. Disclaimer