Even the appendix and tonsils are not as “useless” as we once thought
Throughout history, medical science has not always treated the human body with the same degree of respect. It is enough to recall surgeons of earlier eras: skulls were perforated, and until the end of the 19th century bloodletting (phlebotomy) was widely practiced as a “treatment.”
Even today, a significant share of the most commonly performed surgical procedures is based on the removal of body parts: the appendix, gallbladder, tonsils, adenoids, and even the uterus (usually after the reproductive years). These operations often rest on the assumption that a person can live comfortably without these organs. However, modern scientific research increasingly shows that these “ectomies” are far from as harmless as once believed.
The appendix: the end of the “useless remnant” myth
For a long time, the appendix was presented as a useless evolutionary relic. At school we were taught that this small, finger-like projection of the large intestine had lost its function—much like the vestigial leg bones found in snakes.
This view, however, has lost its scientific foundation. A large study conducted in 2017 under the leadership of evolutionary biologist Heather Smith, Director of the Anatomical Laboratories at Midwestern University (USA), examined 533 mammalian species and revealed that the appendix appears independently in many unrelated species. Smith explains it this way:
“Its repeated appearance in so many different species suggests that it serves an important function.”
That function is thought to be primarily related to the immune and digestive systems. The appendix is rich in lymphoid tissue and plays a role in supporting immune function. In humans, it also harbors large numbers of beneficial gut bacteria.
In 2007, scientists at Duke University proposed that the appendix may serve as a “safe house” for the gut microbiome. In other words, when the intestine is damaged by infection, beneficial bacteria can be restored from the appendix.
Evidence supporting this hypothesis emerged in 2011: individuals without an appendix were found to have a 2.5-fold higher risk of infection with Clostridium difficile, a dangerous intestinal pathogen.
The appendix and its link to Parkinson’s disease
The role of the appendix does not end there. A study published in 2018 showed that the abnormal protein alpha-synuclein—found in the brains of patients with Parkinson’s disease—can accumulate in the appendix. Interestingly, people who had their appendix removed at a young age were observed to have a slightly lower risk of developing Parkinson’s disease. This finding suggests that the appendix may play an indirect role in pathological processes affecting the brain.
Tonsils and adenoids: a hidden protective shield in childhood
New research also shows that tonsils and adenoids are not “dispensable” either. In 2018, an international team of scientists published the results of a long-term study involving 1.2 million Danish children.
Among children who had their tonsils and/or adenoids removed before the age of nine, between ages 10 and 30 there was:
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a two- to three-fold increase in the risk of upper respiratory tract diseases,
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and, contrary to expectations, an increased frequency of ear infections and sinusitis.
Sean Byars, a senior research scientist at the Melbourne School of Population and Global Health, explains:
“Adenoids and tonsils serve as the first line of defense against pathogens entering through the airways or with food.”
Because these tissues are most active in childhood and shrink with age, they have often been considered unimportant in adulthood. However, as Byars emphasizes, their primary role is precisely in childhood—helping the immune system develop properly, with potentially long-lasting effects.
The need for a more cautious approach
Byars notes that these findings do not automatically mandate changes in clinical decision-making, and that treatment decisions for each child must be made on an individual basis. Nevertheless, he concludes:
“Given that these are among the most common operations performed in childhood, our results suggest that a more conservative approach may be wiser.”
It is worth noting that in the United States the number of tonsillectomies has already been declining since the mid-20th century. Similarly, hysterectomies are being performed less frequently, as evidence shows that the uterus retains important functions after childbirth and that many common problems can be addressed with less invasive methods.
Conclusion
Modern medicine increasingly shows that organs once deemed “unnecessary” may in fact play significant roles in the body’s delicate and complex balance. The removal of body parts should be considered only as a last resort, and every decision should be made with careful consideration of potential long-term consequences.