Med thumb sleep unsplash

When it comes to our nightly Zzz count, there's a magic number separating health savants from those in need of a wellbeing upgrade: 30 minutes. According to a new analysis of public health data, published this month in the Journal of Clinical Sleep Medicine, US adults average 6.87 hours of shuteye each night. And based on data collected from more than 20,000 people, researchers found that logging a half-hour more rest matters in terms of maintaining overall health and minimizing risk of cardiovascular disease.  

Researchers analyzed seven years of results from the National Health and Nutrition Examination Survey, (NHANES) which "collects health information about the US population through interviews, medical examinations and lab tests." Their analysis included 22,821 people at least 21 years of age. They looked at NHANES questions on demographics, sleep habits, insomnia, general health status, depression, cardiovascular disease and chronic health indicators, including BMI and smoking history. Basically, they wanted to understand sleep duration with respect to overall health status, as well as specific conditions.

In general, poor health outcomes were associated with shorter sleep: Those with depression reported sleeping about 40 minutes less than their non-depressed counterparts.

Respondents could report sleeping between one and 12 hours a night. While most people estimated getting about seven hours of sleep a night, almost 37% said they logged fewer than six hours a night. In general, poor health outcomes were associated with shorter sleep: Those with depression reported sleeping about 40 minutes less than their non-depressed counterparts.

While this analysis found a strong link between getting more sleep and overall health, it's worth mentioning that both short sleep (less than seven a night) and long sleep (more than nine a night) have been associated with dying earlier and developing chronic disease. In many cases, researchers report a Goldilocks trend: people brimming with health sleep neither too much nor too little. In this case, the trend didn't emerge. When it came to BMI, for example, "subjects who slept nine or more hours," they found, "still had 20 percent lower odds of being obese than subjects who slept six or fewer hours."

Regardless, when it comes to your nightly Zzz-count, you can't go wrong aiming for a #hardeight.