New research has found that having tonsils removed during childhood is associated with triple the risk of upper respiratory tract diseases, including asthma and pneumonia. Researchers said their findings suggest it is best to delay surgery when possible.
Although the operation, known as tonsillectomy, was common in the 1950s and 60s, scientists are now advising against it, saying the benefits do not outweigh the long-term risks.
The study, led by the University of Copenhagen in Denmark and the University of Melbourne in Australia, was published on Thursday in the Journal of the American Medical Association, Otolaryngology Head and Neck Surgery.
The research spanned three decades and examined a variety of diseases, including asthma, flu, pneumonia and chronic obstructive pulmonary disease (COPD), which includes chronic bronchitis and emphysema.
Researchers analysed health records for nearly 1.2 million children in Denmark born between 1979 and 1999, making the new study the largest of its kind. Of these children, 60,400 had either their tonsils or adenoids removed or had a combined surgery.
The team looked at the same participants once they had reached their 30s and found that compared to those whose tonsils were not removed, people who had their tonsils out as children had three times the risk of upper respiratory infections and other conditions. These include colds, asthma, bronchitis, pneumonia and irritation of the mucous membranes in the nose, a condition known as rhinitis.
Researchers also studied the removal of the adenoids as a treatment for recurrent middle ear infections. Doing so was associated with a more than doubled risk of COPD and nearly doubled risk of conjunctivitis and upper respiratory tract diseases.
The team speculated that removing the organs during the first ten years of life could impede the development of the immune system, thereby increasing susceptibility to disease. Researchers said their results suggest doctors should more heavily consider other treatments before removing children’s tonsils.
“Our observed results that show increased risks for long-term diseases after surgery support delaying tonsil and adenoid removal if possible, which could aid normal immune system development in childhood and reduce these possible later-life disease risks,” said Dr Sean Byers, a researcher from the University of Melbourne.
“As we uncover more about the function of immune tissues and the lifelong consequences of their removal, especially during sensitive ages when the body is developing, this will hopefully help guide treatment decisions for parents and doctors.”
The study also analysed conditions that the surgeries are designed to treat. The team found that adenoidectomy was associated with a significantly reduced risk for sleep disorders, while both adenoidectomy and tonsillectomy were associated with significantly reduced risk for tonsillitis and chronic tonsillitis, since the organs these conditions affect had been removed.
However, they found that neither surgery corrected sinusitis or abnormal breathing up to age 30. In fact, combined surgery was found to increase the risk of sinusitis and middle ear infections.
Although severe cases will require the removal of tonsils and adenoids, the “observed results that show increased risks for long-term diseases after surgery support delaying tonsil and adenoid removal if possible,” Dr Byars said.
Tim Mitchell, a consultant otolaryngologist and Royal College of Surgeons council member said the results “certainly warrant further investigation,” according to The Independent.
Mitchell added that the number of tonsillectomies and adenoidectomies has declined substantially over the past few decades. The Telegraph reports that he procedure peaked at about 200,000 operations per year in the 1950s, and has dropped to less than 50,000 today.
Experts have said additional research is needed “to rule out the possibility that patients more inclined towards tonsil pain in childhood are naturally at higher risk of serious respiratory disease,” The Telegraph reports.