En studie publisert i The Lancet i 2003 viste at det å vaske hendene med såpe kan redusere risikoen for å få diaré ganske dramatisk:
We set out to determine the impact of washing hands with soap on the risk of diarrhoeal diseases in the community with a systematic review with random effects meta-analysis. Our data sources were studies linking handwashing with diarrhoeal diseases.
In the absence of adequate mortality studies, we extrapolate the potential number of diarrhoea deaths that could be averted by handwashing at about a million (1.1 million, lower estimate 0.5 million, upper estimate 1.4 million). Results may be affected by the poor quality of many of the studies and may be inflated by publication bias. On current evidence, washing hands with soap can reduce the risk of diarrhoeal diseases by 42-47% and interventions to promote handwashing might save a million lives. More and better-designed trials are needed to measure the impact of washing hands on diarrhoea and acute respiratory infections in developing countries.
Med så enkle midler kan man kanskje redde en million mennesker fra å dø av diaré i utviklingsland hvert år.
En annen nyere studie fra 2008 viste mye av det samme: