By Roopak Goswami
Guwahati: Herbal cigarettes, often marketed as natural, tobacco-free and healthier alternatives to regular smoking products, may be just as harmful, or in some cases even more dangerous than conventional tobacco cigarettes, according to a new Indo-US scientific study.
The joint research by the Indian Institute of Technology Gandhinagar (IITGN) and the University of Illinois Urbana-Champaign (UIUC), United States, found that smoke emitted from herbal cigarettes contained high levels of harmful fine particles and toxic compounds linked to respiratory and cardiovascular diseases.
The findings come at a time when herbal smoking products are increasingly being promoted among young consumers as "chemical-free", nicotine-free and wellness-oriented alternatives to cigarettes.
The researchers compared emissions from two popular tobacco cigarette brands and four widely sold herbal cigarette varieties in India. The herbal products contained combinations of basil, clove, cinnamon, mint, chamomile, green tea and water lily. Some were wrapped in tendu leaves, commonly used in bidis.
The findings were published in the peer-reviewed Journal of Hazardous Materials.
"Our findings challenge the widely held belief that tobacco-free means risk-free," said Sameer Patel of IIT Gandhinagar, one of the study's co-authors. "Emissions from herbal cigarettes are comparable to or exceed those from tobacco cigarettes on nearly every metric we measured."
According to the study, herbal cigarette smoke released around 20 per cent higher concentrations of ultrafine particles smaller than 500 nanometres compared to tobacco cigarettes. Scientists say these tiny particles can penetrate deep into the lungs and bloodstream and are increasingly associated with heart and lung diseases.
Researchers also examined what is known as "oxidative potential" - a measure of the smoke's ability to generate highly reactive molecules that trigger inflammation and tissue damage inside the body.
The study found that particulate matter from herbal cigarettes showed significantly higher oxidative potential than tobacco cigarettes. Tendu-leaf-wrapped herbal variants were found to be particularly hazardous, recording nearly 49 per cent higher oxidative potential than paper-wrapped versions.
In one striking finding, a basil-filled herbal cigarette marketed as "100% natural" and "chemical-free" recorded the highest lead concentration among all tested samples.
The researchers said the study also exposes a major regulatory gap in India. While conventional tobacco products fall under the Cigarettes and Other Tobacco Products Act (COTPA), many tobacco-free herbal cigarettes escape similar warning-label and advertising regulations.
Lead author Alok Kumar Thakur said several herbal brands claimed their products could improve sleep, relieve cough or reduce anxiety, despite limited scientific evidence supporting such claims.
The scientists stressed that the study does not directly measure disease outcomes in smokers. Instead, it analyses the physical and chemical properties of smoke particles and their potential biological impact.
"Combustion, fine particles, soot, trace metals, and the wrapper around them all matter more than what is written on the box," said researcher P.S. Ganesh Subramanian.
The study was conducted by Alok Kumar Thakur and Sameer Patel from IIT Gandhinagar, along with P.S. Ganesh Subramanian and Vishal Verma from the University of Illinois Urbana-Champaign