Having tonsils removed more than triples the risk of developing asthma in later life, a new study suggests. The first long-term investigation into consequences of the common childhood procedure also found increased risk of influenza, pneumonia as well as chronic bronchitis and emphysema.
As many as one in five people who underwent a tonsillectomy went on to suffer from serious diseases they would otherwise not have developed, the study showed.
Experts have said the 30-year research, which involved nearly two million children, indicates that while the modest benefits of the operation – preventing a recurring sore throat – mostly vanish by the age of 40, it boosts the lifetime risk of serious conditions.
They believe that removing the tonsils in the first decade of life may harm the development of the immune system and open the door to future disease.
Published in the Journal of the American Association of Medicine, the study urges paediatricians to limit their use of tonsillectomies as far as possible.
Numbers of the procedure have been dropping since a high of around 200,000 a year in the 1950s, to less than 50,000 today.
Led by scientists at the University of Copenhagen, the research team analysed data from 1,189,061 Danish children born between 1979 and 1999 who had undergone a tonsillectomy in their first nine years.
The procedure was associated with an almost tripled risk, moving the chances of developing asthma, influenza, pneumonia or Chronic Obstructive Pulmonary Disorder (COPD), the umbrella term for conditions like chronic bronchitis and emphysema, to 18.6 per cent.
They also looked at the risks of having adenoids removed in childhood to treat recurrent middle ear infections.
This was found to be linked to a more than doubled risk of COPD, while nearly doubling the risk of upper respiratory tract diseases and conjunctivitis.
“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, who took part in the research at 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.”
Previous research has indicated that these surgeries may also be heightening the risk of breast cancer and heart attacks.
The researchers wrote: “Given that tonsils and adenoids are part of the lymphatic system and play a key role both in normal development of the immune system and in pathogen screening during childhood and early life, it is not surprising that their removal may impair pathogen detection and increase risk of later respiratory and infectious diseases.”
The study found that adenoidectomy was associated with a significantly reduced risk for sleep disorders and both surgeries were associated with significantly reduced risk for tonsillitis and chronic tonsillitis, because the organs had been removed.
However, there was no change in abnormal breathing up to the age of 30 for any surgery and no change in sinusitis after tonsillectomy or adenoidectomy.
Mr Tim Mitchell, a consultant otolaryngologist from the Royal College of Surgeons, said: “Before opting to remove tonsils or adenoids, surgeons will always consider and discuss all treatment options, including non-surgical treatments, with patients, and parents in the case of children.
“There has been a significant decrease in the number of tonsillectomies and adenoidectomies performed in the last few decades. The decision to operate will always be taken with good reason and based on proven benefit.”
Experts say further 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.