Smokers and vegetarians were found to have lower sero-positivity, while those with blood group 'O' may be less susceptible to COVID-19, according to a survey by a survey conducted by CSIR (Council of Scientific Industrial Research), Government of India.
Interestingly, the survey suggested smoking may be protective, despite Covid-19 being a respiratory disease, due to its role in increasing the mucous production that may be acting as the first line of defence among the smoking population. It indicated that vegetarian food rich in fibre may have a role to play in providing immunity against COVID-19 due to its anti-inflammatory properties by modification of gut microbiota.
The pan India survey was conducted by an eminent team of 140 doctors and research scientists to study the presence of antibodies against SARS-CoV-2, the virus that causes Covid-19, and their neutralization capability to infer possible risk factors for infection. The study assessed 10,427 adult individuals working in more than 40 CSIR laboratories and centres in urban and semi-urban settings spread across and their family members. These people voluntarily participated in the study.
It, however, cautioned that there was a need for focused mechanistic studies to understand the effect of smoking and nicotine on coronavirus infection. "Smoking is known to be severely detrimental to health and associated with multiple diseases and this observation should not be taken to be an endorsement, especially given that the association is not proved to be causal," the paper stressed. It indicated that vegetarian food rich in fiber might have a role to play in providing immunity against COVID-19 due to its anti-inflammatory properties by modification of gut microbiota. The survey also found that those with blood group 'O' may be less susceptible to infection, while 'B' and 'AB' were at a higher risk.