For smokers looking to reduce the risks of smoking, the best approach is to quit. But for people who wish to continue smoking, does smoking less or smoking lower tar cigarettes, lower the risks?
Statistical studies indicate that groups of people smoking fewer cigarettes for fewer years have a lower incidence of smoking related diseases than groups smoking more cigarettes for more years.
But the statistics have not established a risk-free level of smoking, and they cannot show that an individual smoker will avoid an associated disease by smoking less.
Historically, and particularly in the UK, public health bodies recommended that reducing the tar in cigarettes, as measured by a standardised machine method, was the best approach to product modification aimed at reducing risks. Today, there is considerable public health opinion that lower tar cigarettes are not associated with lower risks.
To date, there is no scientific evidence to demonstrate conclusively that today’s very low tar cigarettes are less harmful than today’s higher tar cigarettes.
The US National Cancer Institute has also said it believes that the move from the very high tar products of about 50 years ago to today’s generally lower tar cigarettes has not brought public health gains, because smokers have either taken to smoking more or smoking their cigarettes more intensely.
Today’s very low tar products are still relatively new, and a full assessment of them will take longer-term study.
Compensation is the key reason for current doubts about the possible reduction in risk from low tar cigarettes. Compensation means that smokers, when they change the type of cigarette they smoke, may smoke differently. The concern is that when switching to a lower tar cigarette, a smoker adjusts behaviour to get more smoke - either by increasing the number of cigarettes smoked, puffing harder, puffing more frequently or by covering up ventilation holes on the filter.
Some public health bodies are also concerned that people may move to lower tar cigarettes rather than quitting.
We believe that more research needs to be carried out on lower tar products. For our part, we have worked on significantly improving a technique called filter analysis.
This involves collecting the filters of cigarettes smoked by people in normal day-to-day conditions and analysing them for tar and nicotine. Initial work suggests that smokers of cigarettes that are very low tar yield as measured by machines are exposed, on average, to less tar than smokers of high machine-measured tar yielding cigarettes, but that the reduction is not as much as would be indicated by the traditional standardised machine measurement method.
We intend to carry out more research using this technique in several countries and will seek to publish results in peer-reviewed scientific journals. There is more about this in Measuring cigarette deliveries.
We believe that if there is a significant reduction in exposure to tar and other cigarette smoke constituents from lower tar cigarettes compared to high tar cigarettes, then efforts should be made to develop a simple way of communicating this to smokers.
