Jan. 18, 2007 -- Nicotine levels in cigarettes rose 11% from 1998 to 2005, according to a Harvard School of Public Health analysis.
Nicotine is the main addictive ingredient in cigarettes.
The Harvard analysis confirms an earlier report by Massachusetts health officials.
Tobacco industry officials deny there has been a deliberate attempt to manipulate nicotine levels in cigarettes, saying the nicotine in tobacco products fluctuates randomly from year to year.
But the lead author of the Harvard study says the upward trend cannot be explained by random market fluctuations.
“We do agree that there are fluctuations from year to year,” Gregory Connolly, DMD, MPH, tells WebMD. “But when we plotted those fluctuations out, there was a significant increase in nicotine levels on the order of 1.6% per year, or 11% over a seven-year period.”
The report was based on data provided by cigarette manufacturers to the Massachusetts Department of Public Health.
Based on an analysis of the data from 1998 to 2004, Massachusetts health officials reported an upward trend in nicotine levels in cigarettes last August.
That report was strongly criticized by tobacco industry leader Philip Morris USA.
In a news release, company officials argued that the failure to include data from 1997 and 2005 in the original report influenced the findings.
The new analysis, with includes those years, was conducted, in part, to address the criticism, Connolly says.
The Harvard findings confirm a statistically significant upward trend in nicotine levels, as measured in cigarette smoke, between 1997 and 2005.
The increase was seen in all major cigarette types -- including full flavor, light, medium, and ultralight -- and in both mentholated and non-mentholated brands.
Cigarette Makers Respond
In a statement issued today, a spokesman for R.J. Reynolds denied that the company has intentionally increased the nicotine in its cigarettes.
R.J. Reynolds makes top-selling brands Camel, Doral, Winston, Kool, and Salem.
“R.J. Reynolds does not have a program to systematically increase the nicotine content or smoke nicotine yields of its products,” said Jeff Gentry, executive vice president of Research and Development for the company.
Gentry noted that the up and down fluctuations in cigarette nicotine levels may be due to natural variations in nicotine levels in tobacco crops, variations in the “smoking” machines used to test nicotine levels, and changes in the range of brands available to smokers.
A spokesman for Philip Morris USA defended the company’s best-selling brand, Marlboro.
David Sutton tells WebMD that new data for 2006 show nicotine yields for the various types of Marlboro cigarettes have not increased significantly over the past decade.
“The data that we have reported for Marlboro show that in 1997 and 2006 the reported nicotine yield was the same,” he says.
Sutton notes that the company continues to support legislation introduced by Sen. Ted Kennedy (D-Mass.) and others in 2005 that would lead to the regulation of cigarettes and other products containing nicotine by the FDA.
What Do Higher Levels Mean?
Connolly agrees regulation is needed to force tobacco companies to disclose important information about their products.
“People have a right to know what is in these products, and they are not getting that information,” he says. “We need agencies like the FDA that have the competency to step in and regulate these products the way we would any other drug delivery device.”
Higher nicotine levels in cigarettes do not necessarily mean higher nicotine exposures among individual smokers.
Studies suggest that smokers of cigarettes with less nicotine -- light and ultralight brands -- may smoke more cigarettes or inhale more deeply to get the same amount of nicotine as other smokers.
“We can’t say if increases in nicotine levels in cigarettes lead to higher exposures because there are so many variables in the way people smoke,” Connolly says. “We need better human testing to answer this question.”
Donna Vallone of the antismoking advocacy group The American Legacy Foundation agrees there is a need for research into the impact of product nicotine levels on human exposure, specifically as it relates to addiction.
“When you understand what the level of human exposure is, then you can actually gain information about the public health impact,” she tells WebMD.