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How night time noises impact your health

You’re health conscious……….

So getting ENOUGH sleep is high on your agenda.

You do “EVERYTHING” right (more-or-less) and regularly clock up, the 6 – 8 hours of sleep, that is required for good body chemistry.

And yet……….. you have metabolic issues.

Could your sleep, still be contributing to your metabolic troubles ?

This is what a group of European researchers asked…………… instead of focusing on sleep duration, they looked at sleep quality.

Specifically, what happens when you sleep in a “noisy” environment.

Now, the noise they were interested in, was not a screaming baby, or snoring bed fellow, they wanted to know, how transportation noise, impacted metabolism.

For the record………..

This is not a completely new concept.

Epidemiological links

Lots of epidemiological studies have suggested that people who routinely sleep in a noisy environment, are more prone to heart attacks and type 2 diabetes.

The problem with these studies, is when the noise is measured, how loud the noise is on average, is what is primarily considered.

But NOISE is relative…..

Noise boyz

Basically, there is a difference between the noise generated by a four lane highway and  a train track.  In the case of the four lane highway, the noise pretty much never stops, but it’s not THAT LOUD.  Contrast that with the railway line………… for most of the time, the track is empty, so there is NO NOISE.

For most of the time……

But, every now and again, a seriously NOISY, train comes roaring through.

The acoustic characteristic of this noise would be described as a slow rise, to a moment or two of pronounced noise and then a gradual decline.

Now which scenario would be worse : the train track or the busy road ?

Logic says

The train.

The reason, the noise is AN EVENT.

And as an EVENT, it is significantly more likely to scare the bajeebs out of your sleeping brain.

NOTE :  Your brain can still hear when you’re sleeping.

The eventful noise

May not be enough, to actually wake you up, so you’re sitting bolt up right in bed.  But is it enough to arouse you, so your  heart pumps a little faster and  you sleep a little less soundly ?

This is  the question our research team asked.

Noises in the night

The team enlisted the help of 21 adults in PERFECT HEALTH.

Perfect !

To be included, they had to be non smokers and  have no medical disorders, no psychological disorders and no sleeping disorders and they had to have perfect hearing.

These perfectly healthy people, checked into the lab, for a 6 night vacation.

Literally, they never left the lab and everything about their life was managed, what they ate, how much they moved, their light exposure.  EVERYTHING !   Each night was spent in a windowless, sound proof bedroom, which was “blasted” with sounds, played through a loud speaker.

Night sounds

The night sound tracks were real, they had been recorded in different places.  The baseline, “noise” free night, corresponded with chirping crickets and distant traffic. In terms of numbers, this corresponded with a-weighted equivalent continuous sound pressure of 30 dB.

The two experimental conditions, were a little louder, clocking in at 45 dB.

But, the acoustic pattern of the noise was different.

In the first scenario, the non-eventful simulation, the sound recording came from a 4 lane highway and a 2 lane country road.  In the second scenario,  the eventful  simulation, the sound track, was recorded on a 1 lane urban road and a railway track, servicing 4 freight trains and 1 regional train.

Noises in the night

“We” take a look at what happened on the morning of day number 5……

More noise did alter the sleep structure architecture.

Those sleeping in “silence”………..had significantly fewer arousals.

But there was no real difference in sleep quality of the sleepers being blasted with “noise”.  Both groups were a little more grumpy………. there sleep had been interrupted, by the noise.  But, there was little difference between the types of noise.

Eish !  Noise, ALL noise, gets in the way of peaceful sleep.

But, it doesn’t really STOP you from sleeping…………….so what’s the BIG DEAL ?

Eventful noise upsets your metabolism

Well in addition to measuring the effect on sleep variables, the team also looked at what happened to insulin sensitivity.

And this is where there was  a difference, between the noise profiles.

Relative change in the glucose AUC (Area under the curve), following different noise exposures. The black bar shows the median. Copyright 2018 Elsevier Ltd

Here is the data showing fasting blood glucose levels. People sleeping next to the equivalent of a train track, had slightly higher blood glucose levels.

Now, these guys were SERIOUSLY healthy………….

So the difference was not pathological, but there was a difference.

And when it comes to body chemistry, small things  add up.

This study suggests…………..

Silence is golden

Even if YOU THINK, the noise is insignificant, your brain, might feel a little different.   In an ideal world, we would all sleep beside a gurgling brook, being serenade by chirping insects, but that is NOT what happens.

NOISE pollution is part of modern living.

If you must sleep with noise, try to choose an environment, where the noise you are exposed to while sleeping, is low and CONSISTENT i.e. less “eventful”.

If this is NOT an option…………..

Mimic it

One way to do this, is to create white noise while sleeping.   The idea, is to “drown out” the eventful noises, so they fly under your sleeping brain’s radar.

If money is not a problem, buy a white noise machine, otherwise hack it…………

• use a radio that is not tuned into a particular station
• use a noisy ceiling fan or a ticking clock
• download something off the internet and loop it

WARNING :  This strategy won’t work for everyone !   You’ll either LOVE IT or HATE IT !

If you’re in the HATE IT CAMP, that would be me, then you need a plan B.

Noise blockers

The cheap option here, is ear plugs, but a more long term solution would be to sound proof the room.

The point……………….

Good sleep is important for metabolic health.

NOTE : Transportation noise is not the only thing that can lead to fragmented sleep – several sleep disorders, e.g. sleep apnea and restless legs syndrome, also cause fragmented sleep and metabolic chaos. If these are issues for you, they need to be addressed.

Further reading

Want to discover more ways to create BETTER BODY CHEMISTRY ?