FEW things beat stretching out on the sofa after a heavy plate of nasi lemak or a late-night mamak supper.
Yet many of us grew up being told never to lie down right after a meal.
So, is it bad to lie down straight after eating?
Verdict:
TRUE
Yes, lying down soon after a meal may raise your risk of acid reflux and heartburn, although for most healthy people the occasional post-meal lie-down is unlikely to cause lasting harm.
The problem comes down to gravity.
When you are upright, gravity helps keep food and stomach acid where they belong.
Lie down, and it becomes easier for acid to flow back up into the oesophagus, the tube that connects the throat to the stomach.
That backflow is what causes the burning sensation in the chest known as heartburn.
When it happens often, it may point to gastro-oesophageal reflux disease (GERD).
Ireland's Health Service Executive (HSE) notes that reflux symptoms are often worse after people eat, lie down or bend over.
A study by Japanese researchers led by Dr Yasuhiro Fujiwara of Osaka City University, published in the American Journal of Gastroenterology in 2005, looked at how long people waited between dinner and bedtime.
It found that those who went to bed within three hours of eating were 7.45 times more likely to suffer from GERD than those who waited four hours or longer.
The researchers noted that while patients with GERD are generally advised not to eat within three hours of going to sleep, there was a remarkable lack of clinical evidence to support the advice at the time.
Health authorities have since made the three-hour rule a staple of their advice.
The US National Institute of Diabetes and Digestive and Kidney Diseases advises adults with reflux to avoid lying down for three hours after a meal.
The HSE goes a step further, recommending that people do not eat for three or four hours before going to bed.
Closer to home, ParkCity Medical Centre consultant gastroenterologist and hepatologist Dr Saravana Kumar told The Star in 2023 that people should allow at least four hours for food to digest before going to bed.
He also pointed to shift workers who have a heavy meal and go straight to bed, a habit he linked to weight gain and reflux.
If you do need to lie down, the side you pick may make a difference.
A 2022 study published in the American Journal of Gastroenterology tracked the sleeping positions of 57 patients undergoing reflux tests in Amsterdam, the Netherlands.
Lying on the left side was linked to significantly less exposure to stomach acid and faster clearance of acid from the oesophagus compared with lying on the back or the right side.
One of the study's authors reported financial ties to the company that supplied the sleep position devices used in the research.
For those who suffer from night-time heartburn, the HSE suggests raising the head of the bed by around 10cm to 20cm using wood, bricks or books.
It warns against simply piling on extra pillows, as this can put pressure on your tummy and make symptoms worse.
Dr Saravana similarly suggested elevating the head of the bed by 30 degrees to help reduce symptoms.
Of course, not everyone who lies down after a meal will end up with heartburn, and the occasional nap after lunch is unlikely to do any real damage.
But if that late-night supper keeps coming back to haunt you, it may be worth staying upright a little longer.
Sources:
1. https://pubmed.ncbi.nlm.nih.gov/16393212/
3. https://www2.hse.ie/conditions/heartburn-and-acid-reflux
