We all know that proper nutrition and physical activity are cornerstones of maintaining heart health. But a new study points to another factor, quieter yet no less significant, that can affect the risk of heart disease over time. It is a relatively simple daily habit, one that many of us do not attribute importance to at all.
The study, published in the journal BMC Cardiovascular Disorders, examined the connection between sleep routine and the risk of heart disease. Surprisingly, the findings showed that not only how many hours we sleep matters, but also and especially how consistent our bedtime is.
The researchers followed 3,231 adults from Finland, all born in 1966, over a long period of ten years. The participants wore precise sleep monitoring devices for a week, which recorded the time they fell asleep, the time they woke up, and the midpoint of sleep time.
Later, the data were compared with Finland’s national health records to check which participants experienced cardiac events such as heart attack, stroke, heart failure, or mortality related to cardiovascular diseases.
The participants were divided into three main groups. A group with a consistent bedtime, a group with a fairly consistent bedtime, and a group with an irregular bedtime. Even after adjusting for risk factors such as age and sex, the picture was clear.
The result that surprised the researchers
People who went to sleep at varying times, with differences of about an hour and a half to two hours between nights, were at double the risk of developing heart disease compared to those who maintained a consistent sleep routine.
Another interesting finding was that inconsistency in wake-up time did not have the same impact. That is, the most significant factor was דווקא the time of falling asleep.
The risk was particularly high among people who slept less than eight hours per night. A combination of short sleep together with an inconsistent bedtime created a cumulative effect that further increased the risk.
Why bedtime is so important
To understand the findings, it is necessary to be familiar with the body’s biological clock. This is a complex system of about 20 thousand nerve cells in the brain, which regulate the sleep and wake cycles and the body’s activity throughout the day.
When we go to sleep at a fixed time, the body activates a series of important physiological processes. Blood pressure drops, heart rate calms, stress hormones are cleared, and blood vessels undergo repair processes.
When bedtime changes every day, this system is disrupted. The situation is similar to ongoing jet lag, in which the body fails to adapt to a steady rhythm.
A broad impact on health
Beyond the direct effect on the heart, irregular sleep may also lead to increased inflammation in the body. Chronic stress, which makes it difficult to fall asleep at a fixed time, may worsen the process.
Increased inflammation is linked to a wide range of risk factors, including high blood pressure, obesity, and metabolic disorders. All of these contribute to an increased risk of heart disease.
Not by chance, the American Heart Association recently added sleep regularity to the list of key factors for maintaining heart health, alongside proper nutrition, physical activity, and avoiding smoking.
How to implement this in practice
The good news is that this is a habit that can be changed relatively easily. Experts recommend building a fixed evening routine, and maintaining a uniform bedtime as much as possible.
The first step is creating a calming ritual before sleep. Reducing lighting, avoiding screens, quiet reading, or calm music can help the body understand that it is time to relax.
Choosing a realistic bedtime is also important. It is recommended to aim for seven to eight hours of sleep per night, and to stick to a fixed time as much as possible, even on weekends.
If there is a persistent difficulty falling asleep or maintaining continuous sleep, it is important to seek medical advice. Sleep disorders such as sleep apnea are more common than is usually thought, and are treatable.
Proper treatment not only improves quality of life, but may also significantly reduce the risk of heart disease.
The new study emphasizes an important point that is sometimes missed. Sleep is not only a matter of quantity, but also of timing and consistency.
Maintaining a consistent bedtime may be one of the simplest and most effective tools for maintaining heart health over time. In a busy reality where sleep hours often change, this small habit may be exactly what our heart needs.