Our circadian rhythms and the way we sleep have been shown in several studies to be linked to whole-body health and disease risk. According to a large body of scientific research, this relationship applies even to heart health. Several new studies have discovered new connections between heart disease and sleep. Could getting a little more rest to protect you from this common and feared disease?

Heart Disease: A Leading Cause of Death

Do you have a loved one living with heart disease? If so, you are certainly not alone. Heart disease is one of the most common health conditions in the world, becoming increasingly more common as modern people adopt new eating habits and other lifestyle changes. Around one out of four people in the United States will die of some form of cardiovascular disease, and heart disease prevalence is similarly high in many developed nations.

There are several factors that contribute to a person’s chances of developing heart disease and dying from it. Race and other genetic factors play a role. In addition, diet, exercise and certain behaviors such as smoking can affect your heart disease risk. Some diseases such as type 2 diabetes increase your risk of developing heart disease as well.

While most people already know that habits like smoking can affect heart disease risk, several new studies have also found surprising links to sleep. In short, keeping a healthy circadian rhythm may be as important to your heart disease risk as watching cholesterol levels and getting enough exercise.

Disease Risk Affected by Too Much Sleep — And Too Little

Do you find that it is difficult to make time for sleep, or that you just don’t seem to need much of it? Conversely, are you going to bed earlier and waking later than most people your age? According to several studies, sleeping unusual amounts of time, whether too much or too little, may have a significant effect on heart disease risk.

In a recent study, researchers analyzed the sleeping habits and health problems of more than 460,000 people in the U.K. The participants in this study reported health information for more than seven years. When the researchers compared sleep and heart disease risk, there was an interesting connection. People who slept less than six hours a night, unsurprisingly, were at increased risk of developing heart disease. More interestingly, people who sleep more than nine hours a night were also at heightened risk.

Exactly how important was sleep duration in predicting heart disease? Although it was not the only important factor, the risk increase conferred by sleeping outside of a six- to nine-hour range was not small: People who slept too much or too little exhibited around a 20 to 34 percent increase in the probability of having a first heart attack.

Could an Insomnia Gene Link Heart Disease and Sleep?

How can sleep affect heart disease risk so intensely? First, it is important to note that this link is a correlation and not a suggestion of cause and effect. It is possible that people who have severe heart disease simply sleep more or less than healthy people.

Does poor sleep cause poor heart health or does heart disease cause insomnia? Researchers set out to answer this question. Scientists collected genetic information and health histories from more than one million people. These were entered into a computer program that searches for statistical links. The program produced a surprising finding. People who had a common gene known for causing insomnia were several times more likely to suffer from certain types of heart disease, including coronary artery disease, heart failure and stroke.

Although researchers do not know exactly how this gene contributes to cardiovascular programs, it is clearly a driving force. However, it is highly unlikely that this gene is the sole reason for the link between sleep and heart disease. The gene is very rare, causing only an estimated 2.6 percent of insomnia cases and an even smaller portion of heart disease incidences.

How Much Sleep Is Enough?

It is important to get the right amount of sleep, both for heart disease prevention and for your general health. However, doing so is a struggle for many. In general, between six and nine hours is ideal. This guideline may vary from person to person, but most of us will naturally fall somewhere in this range.

Can getting more sleep help to prevent heart disease in people who have insomnia? The jury is still out on this recommendation. Although there is a definite link between sleeping too little (or too much) and heart disease, it is unknown how treatment will affect disease risk in the long term. However, getting enough sleep is a great way to support your mental and physical health throughout your lifetime.