In what must be the ultimate exercise in navel-gazing, an Austrian scientist has solved the mystery of belly button fluff. After three years of research, Georg Steinhauser, a chemist, has discovered a type of body hair that traps stray pieces of lint and draws them into the navel.
Dr Steinhauser made his discovery after studying 503 pieces of fluff from his own belly button. Chemical analysis revealed the pieces of fluff were not made up of only cotton from clothing. Wrapped up in the lint were also flecks of dead skin, fat, sweat and dust.
Dr Steinhauser's observations showed that 'small pieces of fluff first form in the hair and then end up in the navel at the end of the day'.
Writing in the journal Medical Hypotheses, he said the scaly structure of the hair enhances the 'abrasion of minuscule fibres from the shirt' and directs the lint towards the belly button. "The hair's scales act like a kind of barbed hooks," he said. "Abdominal hair often seems to grow in concentric circles around the navel."
The researcher, from Vienna University of Technology also asked friends, family and workmates about their own belly button fluff. Dr Steinhauser established that shaving one's belly will result in a fluff-free navel - but only until the hairs grow back.
Other suggestions for keeping the navel fluff-free include wearing old clothes, as they tend to shed less lint than newer garments, which can lose up to one thousandth of their weight to the belly button over the course of a year. A body piercing can also be used, with belly button rings particularly effective at sweeping away fibres before they lodge.