If you've ever flown on a plane, you'll probably be familiar with an unfortunately common side effect of air travel.
As it turns out, there is a scientific reason people often fart more while travelling on planes or climbing high mountains, and it's even got a name: high-altitude flatus expulsion (HAFE).
The gastrointestinal syndrome was described in a 1981 study as "characterised by an increase in both the volume and the frequency of the passage of flatus, which spontaneously occurs while climbing to altitudes of 11,000 feet (3353m) or greater".
That study found that as air pressure decreases at higher altitudes, gasses inside your body expand and need to be let out, although it was based more on being up in the mountains than inside a pressurised plane.
But additionally, a 2013 study that had participants record how often they farted while driving up an Australian mountain hypothesised that quickly moving from a low altitude to a higher one draws more carbon dioxide into your gut.
Of course, whatever you've been eating and drinking will have a big effect on how much gas you're carrying when you travel and controlling your intake is the primary way to mitigate onboard flatulence.
Here's a few tips to help reduce blowing off in the sky:
- Both the day before you travel and the day of, avoid what are known as FODMAP foods like beans, broccoli and cauliflower, brussel sprouts, garlic, onions, milk, yogurt and soft cheese
- Don't drink fizzy drinks in the airport or on the plane to avoid the carbon dioxide in them
- Eat slowly to avoid swallowing excess air
- Get up and take frequent walks during the flight - ideally to the toilet, as moving about the cabin will break up the gas and help you pass it
- Wear charcoal-lined undies because you may let one slip before you get to the toilet and these undergarments are relatively effective odour neutralisers
But no matter what you do, breaking wind is a natural part of digestion and while you have to be mindful of other passengers, none of us can avoid the scientific realities of being human.