Some people do their dishes and leave the suds on, letting it air-dry, or using a towel. Some rinse it off.
I cannot understand the British habit of washing and rinsing dishes in the same dirty water, and drying them without washing off the soap suds. Is this similar to having a bath and not rinsing off the soap? Am I missing something here?
Ecological water-saving, dirty towels, or nasty soap taste-arguments aside: I wonder if it is unhealthy to leave the suds on, and as a result, ingest minor traces of soap when drinking/eating.
With most washing-up liquids being relatively newer formulations from petrochemicals, to which long-term exposure is still unknown, residuals cannot be beneficial if ingested. The health effects are probably on the order of second-hand smoking; chronic exposure adds up, incidental exposure is probably innocuous.
What does scientific research say?