The nature of navel fluff
Introduction
“By the way, doctor, why do I always find fuzz in my belly button but my wife and her brother do not?” Is not it peculiar that some simple medicine-related questions from everyday life have not yet been answered? Mark Leyner and Dr. Billy Goldberg dedicated their writing efforts to answering exactly such medical questions. The result of their oeuvre was a huge success – their popular scientific medical book “Why Do Men Have Nipples” [1] became a global best seller. The question above attracted the attention of this article’s author, because, though simple, even Leyner and Goldberg were not able to come up with a satisfactory explanation to it:
“One question that cannot be answered, however, is why some belly buttons collect so much lint” [1, p. 57].
The accumulation of navel fluff is probably a widely spread phenomenon. Nonetheless it is an intimate question, thus indeed “you’d only ask a doctor after your third Martini” (the subtitle of [1]) about this topic. The question of the nature of navel fluff seems to concern more people than one would think at first glance. Even the famous journal Nature dedicated some of its precious publication space to an anonymous author’s photograph series entitled “Another matter: Navel fluff” [2]. Three “types” of fluff were shown, from a sailor (“while at sea”), a farmer and an architect. Obviously, these photographs should only attract the reader’s attention. Coincidence or not – these are what one would regard as overwhelmingly male professions. Accordingly, and to the author’s personal experience, navel lint seems to be a phenomenon that affects primarily male adults. Maybe the answer to the introductory question is much simpler than one would expect.
Section snippets
The hypothesis
The author’s hypothesis is that men’s abdominal hair collect cotton fibers from shirts and transport them into the navel by the normal body movement, supported by the direction of the abdominal hairs and their structure. After several hours, these fibers are compacted to form the typical felt-like material. According to the hypothesis, navel fluff has a cleaning function for the navel.
Material and experimental
The author first observed the accumulation of navel fluff in his early 20s. Despite thorough body hygiene including a daily morning shower, the navel filled with lint over the day. The author collected 503 pieces of navel fluff since approximately March 2005 with a total weight of almost 1 g. It was obvious that the fuzz resulted from the collection of cotton fibers from the author’s shirts, because the lint had the same color as the respective shirt. Navel lint material obtained from white
Empirical data and discussion
Questioning (male) friends, colleagues and family members, supported the hypothesis that the existence of abdominal hair is a major prerequisite for the accumulation of navel fluff. Fig. 1 shows each one example of a lint collecting and a not collecting navel.
The mass distribution of the 503 pieces of lint is shown in Fig. 2. The most abundant mass was observed for the range of 1.20–1.29 mg (29 pieces). The average value was 1.82 mg. Only few pieces with masses > 4 mg were collected. In most
Conclusion
The “investigation” of the navel fluff phenomenon allows the following concluding remarks:
- 1.
Abdominal hair causes the accumulation of navel lint.
- 2.
Who would like to avoid the accumulation of fluff can either shave his abdominal hair or wear old T-shirts or dress shirts.
- 3.
The average mass of a navel fuzz collected over a three years period was found to be 1.82 mg, the most abundant individual mass was between 1.20 and 1.29 mg.
- 4.
Assuming that an average T-shirt (180 g) can be worn up to 100 days a year, such
Acknowledgements
The author wishes to thank the many friends and colleagues for their insightful contribution and discussion on this topic and for encouraging him to write this communication.
References (4)
- et al.
Why do men have nipples – hundreds of questions you’d only ask a doctor after your third martini
(2005) - Anonymous. Another matter: navel fluff. Nature (London)....
Cited by (13)
Evaluation of umbilical anatomy via computed tomography prior to single-incision laparoscopy
2020, Medicine (United States)A Concealed “Natural Orifice”: Umbilicus Anatomy for Minimally Invasive Surgery
2019, Surgical InnovationUmbilical Microbiome and Laparoscopic Surgery: A Descriptive Clinical Study
2018, Journal of Laparoendoscopic and Advanced Surgical TechniquesUmbilicus and umbilical cord
2018, Umbilicus and Umbilical CordWhat every medical writer needs to know: Questions and answers for the serious medical author
2015, What Every Medical Writer Needs to Know: Questions and Answers for the Serious Medical Author