For decades, millions of children across the world’s developed nations have undergone surgery to remove their tonsils and adenoids. These lymphatic tissue structures, which serve to trigger a first-line immune response to pathogens entering the respiratory tract, frequently become chronically inflamed in the first years of life.
Since the medical community has long believed that their absence does not significantly impact adult health, many doctors opt to relieve children of the persistent throat pain and ear infections that accompany such inflammation by cutting out the source.
The research team, led by Dr Sean Byars at the University of Melbourne, examined medical records from a massive dataset of approximately 1.2 million Danish individuals whose health had been followed from birth to age 10, and in some cases, up to age 30.
After comparing subjects who had their tonsils or adenoids removed before age 9 to controls, Dr Byers and his colleagues found that those who underwent tonsillectomy were three times more likely to suffer from either allergic or infectious upper respiratory tract diseases – including asthma, influenza, and pneumonia, among others – in the following years. Undergoing an adenoidectomy was associated with a two-fold higher rate of these diseases as well as chronic pulmonary obstructive disease (COPD) and conjunctivitis.
And surprisingly, the analysis indicated that many of the troublesome symptoms of tonsillitis and adenoiditis that removal surgeries aim to ameliorate – breathing problems and chronic ear or sinus inflammation – often return soon after the operation, meaning that any possible short-term benefits are paltry when stacked against the long-term risks.
This was the first investigation to assess the long-term impact of tonsillectomy and adenoidectomy on a variety of diseases, and the authors note that the large number of patients used in the analysis lends serious weight to the results.
In light of the significant risks revealed here, Dr Byars and his team propose that these procedures should be avoided when alternative treatments are available. If other options run out, physicians should attempt to delay surgery for as long as possible so as to allow the child’s immune system to develop further.
“Given that tonsils and adenoids are part of the lymphatic system and play a key role both in the normal development of the immune system and in pathogen screening during childhood and early-life,3 it is not surprising that their removal may impair pathogen detection and increase risk of later respiratory and infectious diseases,” they conclude.
“The growing body of research on developmental origins of disease has convincingly demonstrated that even small perturbations to fetal and childhood growth and development can have lifelong consequences for general health.”