Smokers, Vegetarians At Lower Risk Of Contracting Covid-19: Study

A Council of Scientific and Industrial Research (CSIR) survey suggests that smoking and a vegetarian diet may provide protection against Covid-19. However, scientists and authors of the survey are still studying the issue, as the link between vegetarianism, smoking and less  Covid-19 seropositivity, is still just a reported observation. 

“There is some such data elsewhere for smoking. There are many (studies) that have found the opposite too. As I said this is an association. Smokers and those with chronic obstructive pulmonary disease (COPD) are at greater risk of death. We do not advocate smoking. Most importantly, low seropositivity can be due to lower production or faster loss of antibodies also. The topic needs further study", clarified Anurag Agarwal, director of the Council of Scientific and Industrial Research-Institute of Genomics and Integrated Biology (CSIR-IGIB). 

Based on voluntary participation, CSIR took samples for its study from 10,427 adult individuals working in its laboratories or institutions and their family members. These samples were taken to study the presence of antibodies against SARS-CoV-2, the virus that causes Covid-19. The study found that about 1,058 (10.14 per cent) of the 10,427 people had antibodies against SARS-CoV-2. However, it did not specify how many of these people were smokers or vegetarians.  

“In the absence of specifically designed studies, any hypothesis on the effect of smoking/nicotine uptake on symptomatic Covid-19 remains speculative,” according to an editorial published in the journal ‘Tobacco Induced Diseases’. 

While there isn’t much scientific literature on the effect of a vegetarian diet on chances of getting ill with Covid-19, the CSIR study does suggest that vegetarianism is associated with less Covid-19 seropositivity.

K Srinath Reddy, president of the Public Health Foundation of India, told PTI in an earlier interview that there is no proof at the moment that vegetarians are protected against Covid-19. 

However, he said people who take a lot of fruits and vegetables as part of their natural diet have better innate immunity and might be able to fight the infection much better.

According to immunologist Vineeta Bal, while the CSIR study provides useful data, there are some limitations to it.

“The study is family-based -- transmission within the family is an important parameter in such a situation and data provides no information about it. Family as a unit is also important while analysing parameters such as smoking, food habits etc,” Bal, visiting professor at Pune’s Indian Institute of Science Education and Research, told PTI.

“Samples are also primarily city-based. Male-female ratios don’t reflect the population distribution. These concerns are important from a public health perspective as recommendations for issuing guidelines about food, smoking etc. should have a more sound and wider basis,” she said.

She also noted that the CSIR study is an observational one and such studies can only highlight associations.

“More focused studies will be needed to strengthen or refute observations reported in this study. In any case, I think it is premature to derive public guidelines out of this study for people to make an informed choice,” Bal said.

With PTI inputs