How alcohol actually affects sleep

Just two glasses of wine with dinner is enough to reduce sleep quality by nearly 40% and the effects are worse for young people.

That's the main take-home message from a Finnish study of more than 4000 men and women aged 18-65.

In the study, the researchers recorded the participants' heart rate variability in uncontrolled, real-world conditions to assess the quality of their restful state.

Alcohol intake was broken down into low (≤0.25g/kg), moderate (>0.25-0.75g/kg) and high (>0.75g/kg), calculated on participants' weight.

Each person was