The next time you go to bed, start sawing those logs like your life depended on it. Two national studies indicate that may actually be the case.

In one study National Cancer Institute researchers tracked 239,896 American men and women for 14 years. In that time 44,000 subjects died. The study found short sleep duration (seven hours a night or less) predicted higher mortality, particularly from cardiovascular causes.

A second study by the National Institutes of Health studied 7,690 men and women free of heart disease. The 10-year risk of heart disease was lowest for those sleeping seven hours a night compared to those sleeping either more or less.

In an age when we filter our tap water, seek out organic produce and exercise, it seems we’re skimping on the one health benefit that is all-natural and free: sleep.

Sunder Rao, a cardiologist at Butler Memorial Hospital for eight years, was unsurprised by the studies’ conclusions.

“We’ve been aware of the studies’ connections between sleep and cardiovascular problems for many, many years now.”

Rao said, “Sleep apnea is strongly connected with cardiovascular problems. It is not just the quantity of sleep, but the quality of sleep.”

He said, “Apnea is where you cease to breathe. It isn’t just snoring, you stop breathing and start coughing and choking. It happens in a cyclical fashion.”

Rao said sleep apnea is closely linked with high blood pressure, cardiac arrhythmia and atrial fibrillations.

“With these large studies, there could be factors extraneous to the study,” said Jeffrey Lynn, Slippery Rock University associate professor of exercise and rehabilitative sciences.

“Stress causes anxiety and high anxiety causes people to be unable to sleep. Depression causes people to wake up and stay awake,” said Lynn.

“It’s possible anxiety and depression are a possible correlation to cardiovascular disease.”

“And if folks don’t get a good night’s sleep, they are prone to anger. If you are walking around angry, that’s not good for your heart,” Lynn said.

If lack of sleep or poor sleep are detrimental to your health, how does adequate sleep maintain health?

“Nobody has answered that question,” said Rao. “Every living thing needs some sleep. Sleep is extremely important.”

He added at least seven hours for men and eight for women are the recommended daily sleep hours.

“Sleep deprivation is one of the first methods used to extract information from people,” Rao said.

Karen Colbert, senior director of communications and marketing at the American Heart Association Great Rivers affiliate, said the association believes most people need six to eight hours of sleep each day.

“Poor sleep quality is linked to an increased risk of high blood pressure,” Colbert said.

“People who are sleep deprived have slower metabolism and more difficulty losing weight, often the effect of not wanting to exercise or participate in other healthy habits,” she added.

Colbert said, “When you get adequate sleep not only does it increase heart health … it helps your stress hormones, your immune system, your breathing and your mental status.”

Lynn said it’s speculated the body uses sleep as a time to repair itself from daily exertion.

“If there’s not enough sleep, there’s no rebuilding,” he said.

Rao said sleep’s health benefits are believed to be tied to the Rapid Eye Movement or REM cycle of sleep.

“In REM sleep, a person’s heart rate and blood pressure go up,” said Rao.

The REM phase is very important. Scientists theorize REM might be involved in processing memories, learning and balancing moods.

Rao said the exact reason are unknown, but a lack of REM sleep is detrimental to a person’s health.