Research

Mixed

Chronic sleep loss (defined as <6 hours or >8-9 hours per night) significantly increases the incidence of cardiovascular disease, including coronary heart disease and stroke, and is associated with incident diabetes, weight gain, and all-cause mortality.

Aim for 7-8 hours of sleep per night. Both sleeping less than 6 hours and more than 9 hours is associated with significantly higher risks of heart disease and stroke. Prioritizing sleep duration is as critical for long-term health as diet and exercise.

GoodSupportsHIGH confidence
Relative to those who slept between 7 and 8 h per night, those who slept less than 6 h exhibited a 48% increase in the incidence of coronary heart disease and 15% increase in the incidence of stroke, whilst those who slept greater than 8 to 9 h exhibited a 38% increase in coronary heart disease, a 65% increase in stroke and a 45% overall increase in cardiovascular disease.
Ignacio Perez-Pozuelo et al. · npj Digital Medicine · 2020

Why this rating

Based on a large meta-analysis of 470,000 individuals and other large epidemiological studies cited.

Source

The future of sleep health: a data-driven revolution in sleep science and medicine

Ignacio Perez-Pozuelo et al. · npj Digital Medicine · 2020

DOI 10.1038/s41746-020-0244-4

narrative_reviewCited 306×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →