WASHINGTON — A food allergy can be quite the inconvenience, but it could also mean you're less susceptible to contracting the COVID-19 virus, a new study from the National Institutes of Health has found.
The Human Epidemiology and Response to SARS-CoV-2 (HEROS) study involved more than 4,000 people in nearly 1,400 households and found that that having a self-reported, physician-diagnosed food allergy cut a person's risk of infection in half.
However, the study also found having asthma and other allergic conditions - like eczema and allergic rhinitis - were not associated with reduced COVID infection risk.
While researchers are still not certain why having food allergies may reduce the risk of COVID infection, they speculate it may have to do with a protein called an ACE2 receptor. According to the study, the type of inflammation provoked by a food allergy may reduce the levels of ACE2 on the surface of airway cells, and COVID is known to use this receptor in order to enter cells.
The study surveillance took place between May 2020 and February 2021, before the widespread rollout of COVID-19 vaccines and before the delta and omicron variants appeared. Researchers found everyone in the study had around a 14% chance of contracting COVID-19 during the six-month surveillance period.
The findings were published Wednesday in the Journal of Allergy and Clinical Immunology.
Still, the study also found that the risk of transmission in a household with a child regardless of allergy status was high, with experts noting their high rate of asymptomatic infection, potentially high viral loads and close physical interactions with relatives. Researchers underscored that vaccines are still the most effective mechanism to prevent infection or severe disease.
“The HEROS study findings underscore the importance of vaccinating children and implementing other public health measures to prevent them from becoming infected with SARS-CoV-2, thus protecting both children and vulnerable members of their household from the virus,” said Dr. Anthony Fauci, director of the National Institute of Allergy, and Infectious Diseases (NIAID), part of NIH.
The HEROS study also monitored other risk factors for COVID infection and confirmed that obesity was a leading contributor to infection. According to the research, every 10-point increase in body-mass index (BMI) percentile raised the risk of infection by 9%.
"The observed association between food allergy and the risk of infection with SARS-CoV-2, as well as between body-mass index and this risk, merit further investigation," Fauci said.