“Largely” preventable, heart disease is usually connected with a build-up of fatty deposits inside your arteries or an increased risk of blood clots. There are various different types of this condition, with coronary heart disease being considered one of the main kinds.
There are currently about 7.6 million people in the UK living with a heart or circulatory disease, according to the British Heart Foundation.
From high blood pressure to smoking, there are different risk factors that can lead to this condition.
And while certain influences like age and family history of heart disease are impossible to change, others can be easily modified.
Sleeping habits belong to the latter category and a new study identified a particular way of resting that can boost your risk of heart disease.
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“Close the blinds, draw the curtains and turn off all the lights” before bedtime is the message from the study from the Northwestern University Feinberg School of Medicine.
The research explains that having even a moderate ambient light on while you sleep can harm your cardiovascular function.
Sleeping in a lit room can increase your heart rate, the force with which the heart contracts as well as the rate of how fast the blood is conducted to your blood vessels for oxygenated blood flow.
What’s worse, just a single night with your bedside lamp on can affect your heart and blood vessels.
The senior study author Dr Phyllis Zee said: “The results from this study demonstrate that just a single night of exposure to moderate room lighting during sleep can impair cardiovascular regulation, which are risk factors for heart disease.
“It’s important for people to avoid or minimise the amount of light exposure during sleep.”
The study also noticed that sleeping with a light on can also increase your insulin resistance the next morning, which represents a risk factor for diabetes.
Think about it this way, evidence has previously shown that exposure to light during the daytime boosts your heart rate through the activation of the sympathetic nervous system.
This is helpful for facing all the challenges your day-to-day life brings as it helps to kick your heart into “high gear” and heighten alertness.
However, this new study noticed that leaving the light on when you are dozing off is associated with a similar effect.
This leaves your body unable to rest properly during the time when you start gathering your energy for the next day.
Dr Daniela Grimaldi, a co-first author, said: “We showed your heart rate increases when you sleep in a moderately lit room.
“Even though you are asleep, your autonomic nervous system is activated. That’s bad. Usually, your heart rate together with other cardiovascular parameters are lower at night and higher during the day.”
Also, exposure to artificial light at night during your sleep is quite “common”, from bedside lamps and TVs to the light sources outside.
“These findings are important particularly for those living in modern societies where exposure to indoor and outdoor night-time light is increasingly widespread,” Zee noted.
While light is essential during the daytime, swap your favourite lamp for a dimly lit room tonight, the study concludes.