People with food allergies have 50% less risk of becoming infected with the virus that causes COVID-19 than people who don’t have food allergies, a National Institutes of Health study found.
The Human Epidemiology and Response to SARS-CoV-2 (HEROS) study monitored the health of 4,000 people in 1,400 households between May 2020 and February 2021. This was a time when COVID vaccines were unavailable to the public or were not widely available, the NIH said.
During the study, every household had at least one person 21 years old or older. Somebody in each household took nasal swabs every two weeks to test for COVID.
Researchers weren’t sure why people with food allergies had a lower COVID risk. It’s possible that type 2 inflammation, which is often caused by an allergic reaction, reduces the levels of ACE2 receptors on the surface of the airway cells, the study says. The ACE2 receptors are entry points for COVID, fewer receptors mean less chance of COVID invading the body.
Another possibility considered was that people with food allergies dine out less often and have less chance of catching COVID, the study said. But researchers found that people with food allergies have only slightly lower levels of community exposure than the other households.
The HEROS study found that people with asthma and other allergic conditions, including eczema and allergic rhinitis, did not have a lower or higher risk of catching COVID. However, the study appeared to confirm previous research showing a connection between obesity and COVID risk.
The NIH study calculated that a 10-point increase in BMI (body mass index) percentile raised a person’s risk of COVID infection by 9%. “Participants who were overweight or obese had a 41% greater risk of infection than those who were not,” the study said.
Children 12 or younger were just as likely to catch COVID as teens or adults. However, 75% of child cases were asymptomatic, the study said.
NIH 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 Anthony Fauci, White House chief medical advisor.
“Furthermore, 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.”