What’s that in your belly button? Science has the answer

The Washington Post – There has been a great deal of scientific studies devoted to the seemingly insignificant topic of what’s hiding in our navels.

An intrepid scientist analyzed his own navel fluff: Georg Steinhauser at the Vienna University of Technology in Austria collected 503 fluff samples over the course of three years. After the initial analysis, it was found that the navel lint contained house dust, skin cells, sweat, as well as clothing fibers.

After further (and undoubtedly fascinating) investigations by his friends, family, and colleagues, he concluded that belly hair was a prerequisite for navel lint buildup, and that old T-shirts or T-shirts were less likely to produce flunfla than new clothes.

The scientist even shaved his stomach to confirm his hypothesis about abdominal hair.

Steinhauser speculated that people who collect more fluff may have healthier navels than those who don’t, because all the excess dirt is removed by the lint rather than sticking to the skin. But as for cleaning, it is recommended that you clean your belly button the same way you would any other part of your body.

In addition to belly hair and new clothes, there are a few other factors that determine why and how dirt builds up in our navels.

Karl Kruszelnicki, of the University of Sydney, Australia, did research on 4,799 people and noted that being male, having an “inner” rather than an “external” navel, and being older were factors associated with accumulating more fluff. His work was among the winners of the 2002 IgNobel Prize, which is given for funny scientific achievements.

And in further proof that the true pursuit of knowledge knows no bounds, a mechanical engineer at the Indian Institute of Technology Patna decided in 2018 that he would ask the real hard questions: What is the physics behind the production of navel fluff? Is it possible to make a mathematical model?

He determined that, on a microscopic level, body hair acts like a sawtooth untangling tissue fibers during the movement of the breathing cycle—inhalation and exhalation—when our clothes constantly rub against our stomach. The hairs in this area tend to curl towards the lower navel, and the fibers trapped in them descend below the navel, losing contact with the tissues.

As the dander continues to flow, it mixes with sweat and skin cells, and the result is a beautiful, compact mass of fluff that piles up with mathematical precision. It starts linear, then grows quadratic over time – in case you were wondering.

Your navel probably doesn’t collect fluff, but every now and then you find a little dirt in there. This is also normal, especially in the “inner” navel, which is, after all, a small slit with several small folds in the skin, perfect for trapping oils and sweat. Infection is rare, but if you notice pain or a discharge in the area, talk to your doctor.

Several studies tested the microorganisms found in both the navel and the dirt in the navel, which is mainly composed of dead skin cells. The most common type of umbilical sludge is corynebacteriumIt is a generally harmless microbe that is abundant in other moist areas of the body, such as the inside of the nose and under the armpits.

The self-cleaning rituals that each person considers to be the most “healthy” vary greatly. From a medical point of view, everyone agrees on certain practices, such as cleaning up visible dirt or washing hands while preparing food or after using the bathroom. But shower frequency is something more subjective. If in doubt, consult your doctor. / Translated by RENATO PRELORENTZOU

Trisha Pasricha, MD, is a physician at Massachusetts General Hospital, instructor of medicine at Harvard Medical School, and a medical journalist.