Travelling on a plane can be an uncomfortable experience. Your clothes feel too tight, you feel like you need to keep farting or feel like you need to go to the toilet! Why does this happen? What can you do to reduce this?
The science of gas and pressure
Intestinal gas is mainly produced by bacteria in the gut breaking down food that our body has otherwise not been able to. Humans normally fart out this excess gas in small amounts 10-15 times a day. In a plane, the pressure in the cabin when flying at cruising altitude is lower than when on the ground. The scientific equation that describes the volume of gas at different pressures is called Boyles’ law.
Boyles’ law:
Volume 1 (V1) x Pressure 1 (P1) = Volume 2 (V2) x Pressure 2 (P2)
The pressure at sea level is 100 kPa (760 mmHg). Most modern airliners have a cabin pressure of around 80 kPA (600 mmHg) which is equivalent to the atmospheric pressure at 2000 m (6000 ft).
If we assume that a human adult has 200mls of gas in their gut when the plane takes off we can work out what the volume of gas is at cruising altitude:
200mls x 100 Kpa = V2 x 80 Kpa
therefore V2 = (200 mls x100 kPa) /80 kPa
i.e. V2 = 250mls
You can see that the amount of air in the gut increase by 25% at altitude compared to when on the ground. As a result you feel bloated, your pants don’t fit and you need to fart! Don’t hold it in, you will feel better when you let it out. If you are too embarrassed to do this or worried about the sound and smell then keep reading…
Food that produces gas
You can reduce gas by avoiding foods that your body does not break down well. These include:
- Whole grains (including most breads served on a plane)
- Broccoli, Brussels sprouts, cabbage, and other vegetables
- Fruits
- Other starchy foods such as potatoes, pasta and rice
- Lactose (milk products)
- Beans (this makes the top of most lists, but honestly how many people eat beans when flying? I have put it at the bottom of mine)
The poorly broken down food is fuel for the gut bacterial. The amount that is left for bacteria to ferment is dependent on the amount of an enzyme called alpha-galactosidase. Humans make this enzyme in saliva and in the pancreas to aid digestion. The amount of enzyme you make reduces as you age. The odd one out on the list is lactose (milk products) that requires the enzyme lactase to break it down.
The undigested food is fermented by the bacteria in your colon producing hydrogen and carbon dioxide i.e. gas….
What can you do to reduce the gas produced from these foods?
- Don’t eat these foods. Doesn’t give you too many dietary options does it!
- Use an enzyme supplement when you eat that contains alpha galactosidase. The one we recommend is the premium digestive enzymes and probiotic capsules by MAV nutrition. This product also contains lactase to help break down any dairy products you may have on the plane. It is GMO free, made in the USA and don’t contain any animal products. Take a capsule with any food you eat at the airport or on the plane and should make a big difference to how much you need to fart on a plane!
Is there anything else that may cause gas?
Yes. Swallowing too much air can contribute the sensation of feeling bloated. If you are anxious when you fly then you could be subconsciously gulping air. If you need some strategies to relax, then Soar: The breakthrough treatment for fear of flying is available in paperback and on kindle from Amazon. It gets great reviews from people who have struggled with the fear of flying.
What other things make you fart on a plane? (give us a list in the comments section)
