A study funded by the National Institutes of Health has found that people with food allergies have reduced risk of COVID-19 infection, being asthmatic conferred no extra risk of infection; but being overweight, obese, or having a high body mass index (BMI) increased the risk of infection.
“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,” said Anthony Fauci, director of the National Institute of Allergy, and Infectious Diseases (NIAID).
The study (pdf) was conducted from May 2020 to February 2021, prior to the widespread rollout of vaccinations in the United States, monitoring more than 4,000 people in nearly 1,400 households that included at least one person aged 21 years or younger.
Participants were recruited from existing NIH-funded studies that focused on allergic diseases, with around half of the participating children, teenagers, and adults self-reporting allergies such as food allergies, asthma, eczema, and allergic rhinitis.
As lockdown controls were in place, as part of the 6-month study, nasal swabs were collected from households twice a week to test for infection.
However, only 65.6 percent of the total 55,236 swabs were successfully collected and tested.
The study found individuals with allergy diseases such as asthma, eczema, or upper respiratory allergy did not have any increased risk for COVID-19, while participants that self-reported food allergies had a decreased infection rate by 50 percent.
Conversely, participants who were overweight or obese—who made up 63 percent of the adults in the cohort—had an elevated risk of infection by 41 percent.
A high BMI score conferred infection risks with an increase of 9 percent in infection risk with every 10-point percentile increase in BMI.
Participating children aged 12 years or younger were found to be just as likely to become infected, but 75 percent of child infections were asymptomatic.
The findings of the study are supported by previous literature that asthma patients had lower risk of COVID-19, with a UK study even finding reduced risk for the condition.
Other studies have also demonstrated elevated risks of COVID-19 infection and severe sickness for high BMI and obese individuals, though no current studies have shown the protective aspects of food allergies against COVID-19.
Giving reasons for why infection risks are lower for people with food allergies, the authors speculated that type 2 inflammation; a characteristic of allergic conditions, may reduce levels of a protein called the ACE2 receptor on the surface of airway cells.
SARS-CoV-2 uses the ACE2 receptor to enter cells, so reduced levels could limit the virus’s spread and control the infection.
This explanation has also been used to explain studies that found asthmatic individuals had a reduced risk of infection, though the same findings were not repeated.
Despite the unexpected news, the findings of the study may not even be reliable nor accurate, given that only 65.6 percent of nasal swabs were collected and tested over the entire study period, with around a third of the swabs not tested at all.
“While this likely resulted in an underestimation of the incident infection rate, it could also cause underestimation of the risk associated with asthma, obesity,” wrote the authors, implicating possible outcomes that may challenge their current conclusions.
“Different types of systemic and airway inflammation may contribute to the variable infection risk and understanding the mechanisms explaining these observations may offer new pathways for disease prevention.”
The Epoch Times contacted the NIH for comment.