Lead author Professor Jacob Rosenberg told the Herald it was funny how the paper kept coming back to haunt him a decade on. However, despite ripe scatological humour, the peer-reviewed publication was perfectly sincere in its findings.
“The physiology must be the same for a dog as for a human. So, we would expect increased flatulence in animals as in humans,” he said.
Professor Rosenberg, of the University of Copenhagen’s Department of Surgery, was inspired to produce the paper after the experience of a long-haul flight to Auckland from his native Denmark.
Watching his empty plastic water bottle spontaneously crumple on arrival, he realised that there was a large change of pressure in the cabin.
Although modern plane cabins are pressurised, the equivalent change in pressure is equivalent to being at an altitude of 2500 metres, causing gas to expand.
The same thing must be happening in passengers’ guts, he thought. This unlikely ‘eureka’ moment was the fart that launched a thousand theses.
The ileocecal valve, which prevents intestinal gas from passing from the colon back into the small intestine, means that there is only one way for the pressure to go: out into the cabin.
The resulting gas is nothing to worry about, and is described as a “natural and an invariable consequence of digestion”.
The problems of “flatus” in plane cabins were described to be more of a “social character”.
Whereas “holding back flatus on an airplane may cause significant discomfort and physical symptoms”, warns the report.
Fortunately, the gastroenterologist and his team were full of helpful suggestions as to how to mitigate the problem of farts on planes.
Charcoal underpants
While the report advised there was little you could do to stop trapped gas from becoming ‘untrapped’, there were several ways the smell could be battled.
“We humbly propose that active charcoal should be embedded in the seat cushion, since this material is able to neutralise the odour.”
Active powdered charcoal was identified as a proven way to absorb stray odours. Some airlines have installed charcoal filters in plane HEPA ventilation systems to improve cabin air quality.
The study suggested embedding the material in plane seats, blankets and even passenger “trousers” to absorb obnoxious particles.
Reduce fibre in airline meals
The nutritional value of an in-flight meal is not notoriously high. However, the report made several suggestions to reduce gas produced during digestion.
A nutritional analysis of an airline meal published in the Annals of Internal Medicine found fibre content was only around 23 per cent of the daily recommended intake.
“However, knowing that high-fibre content produces flatulence, the amount of fibre in airline meals could be reduced even further.”
The provision of more gluten and lactose-free meals on planes was also recommended, to reduce adverse effects for passengers with intolerances to these food substances.
Methane breath test
One of the less palatable solutions to flatulent passengers was the suggestion of breath-testing travellers upon embarkation.
The volume of methane on a passenger’s breath was shown to be indicative of how active their digestive tract was, and therefore the volume of gas produced.
While the proposal of banning passengers over a certain limit was considered distasteful, Rosenberg said he could imagine certain budget airlines charging “flatus quotas” or “fart credits” to offset their... *ahem*… emissions.
In line with carbon credits, as flatulence contains large amounts of CO2, passengers may be allowed to buy “flatus quotas”.
Otherwise, it was suggested that breath tests could help prioritise which passengers to bump on over-full flights.
“In case of overbooking, it would seem sensible to abandon flatulent people for the sake of flight comfort.”
