Times of India
27 April 2011
By Kounteya Sinha
New Delhi, India

You thought that puffing away on cigarettes only could result in a racy heart?
A new research by doctors from India’s premier All India Institute of Medical Sciences has found that even chewing tobacco – as less as one gram – significantly raised heart rate.

What was most significant among the findings was that when doctors asked patients with normal coronary arteries to chew tobacco in the catheterization laboratory, a striking transient narrowing of normal coronary arteries were visible even with the slightest chewing tobacco.

This, doctors say may not be such a major worry for youngsters, but when adults with already some amount of narrowed arteries continue to chew tobacco, further constriction of arteries would mean a significant decrease in amount of blood reaching the heart. This raises the chances of a heart attack.

Also, for the first time, the study showed that chewing tobacco could lead to peripheral vasodilation which means the blood instead of reaching the brain would remain at peripheral arteries like hands and feet This could be the reason why most first–time users of chewing tobacco suffer giddiness and vertigo.

The study has now been published in the American Journal of Cardiovascular Drugs. Speaking to TOI, Dr Balram Bhargava, senior author of the study said “Never before has it been shown that chewing even a slight amount of tobacco could cause narrowing of major heart arteries by over 14%. For people already having narrow arteries with fat deposit, this would mean a further constriction and angina or pain everytime the person runs or is anxious.”

Twelve habitual tobacco chewers undergoing elective coronary angiography were included in the study. Changes in the heart were calculated at baseline and at 15 minutes, 30 minutes, and 60 minutes following the start of tobacco consumption.

Following coronary angiography, a continuous cardiac output pulmonary artery catheter was used to measure the right heart pressures and cardiac output. Having obtained baseline blood pressure data, 1 gram of tobacco was given to be chewed. Subsequently, data were obtained periodically over a period of 60 minutes.

Around 10 minutes after tobacco was given, doctors estimated the diameter of the left anterior descending (LAD) artery – one of the main arteries of the heart, by a coronary angiography.

The results showed that chewing tobacco led to a significant increase in heart rate (from 68.3–12.4beats/ min to 80.6–14.6 beats/min) – the highest being at 10 minutes after consuming chewing tobacco. And cardiac output from 3.8–0.45L/ min to 4.7–0.64 L/min, peaking at 15 minutes.

Chewing tobacco was associated with coronary vaso–constriction (LAD diameter change from 3.17–0.43mm to 2.79–0.37 mm).

One reason for this, doctors say could be the higher amount of nicotine in India chewing tobacco products like khaini and zarda.

The researchers estimated that Indian smokeless tobacco products for chewing contain more nicotine (13.8–65.0 mg/g) than American smokeless tobacco products.

Dr Ambuj Roy, associate professor of cardiology at AIIMS and one of the authors said although the ill effects of cigarette smoking is known to cause acute hemodynamic effects, there was a lack of data concerning such effects of chewing tobacco.

“Chewing tobacco not only increases the workload on the heart and makes in pump faster causing it to stress but it also reduces the diameter of heart arteries acutely,” Dr Roy added.

According to the recently released Global Adult Tobacco Survey (GATS), 21% of Indian population is addicted to smokeless tobacco alone and another 5% percent smoke as well as use smokeless tobacco. Around 75% of the 275 million Indians consume smokeless tobacco products.

A large number of children and youth in India are addicted to smokeless tobacco. Smokeless tobacco contains nicotine, which is highly addictive. There are 3095 chemical components in tobacco, among them 28 are proven carcinogen.

Smokeless tobacco causes oral cancer, pancreatic cancer, increased blood pressure and heart rate and adverse reproductive outcomes. One third of males use smokeless tobacco products. Khaini is used the most, followed by gutkha. Around 91% of female tobacco users use smokeless products like betel quid with tobacco is used the most, followed by gutkha and khaini.