You will no doubt be heartened to hear that a number of scientific surveys have been undertaken regarding bellybutton fluff .
What follows are my learned findings:
They have all found that the fluff is generally blue in colour and is more prevalent in the navels of certain types of people . To answer why it tends to be blue, the origin of the lint must first be considered . It is thought that the lint comprises fibres from clothing, as well as some skin cells, that are channelled to the navel from below by hairs on the stomach throughout the day as the body moves . These hairs also help to dislodge the fibres from the clothes . Generally speaking, the stomach hairs are particularly important in this process, which is why hairy men tend to accumulate the most fluff . Similarly, older (and, therefore, hairier) people also often acquire more lint, while shaving the stomach has been found to reduce navel-fluff buildup . It has also been found that men with big guts accumulate more fluff, probably because their beer bellies press harder against their Manchester United football tops, causing more fibres to dislodge, and also because their navels tend to be deeper, allowing more fluff to accumulate there . The reason why the fluff stays in the navel is either because the navel contains perspiration that the fluff clings to (as some suggest) or because the fluff simply lodges there because the navel is set lower than its surroundings . Supporting this theory is the fact that outward-protruding navels rarely collect fluff . The reason why the fluff is coloured blue has been the subject of much conjecture, but it’s generally thought to be related to the colour of the clothing worn below the navel, which is generally dark colours such as blue . However, the fluff of people who wear a variety of colours still tends to be blue, because blue is the result of combining a number of different colours, just as the fluff found in the filters of washing and drying machines tends to be bluish in colour being a combination of the fibres from all of the clothes in the load .