Data supplied by tobacco companies strongly suggest that in recent years manufacturers deliberately boosted nicotine levels in cigarettes to more effectively hook smokers, Harvard researchers conclude in a study being released today.
The companies increasingly used tobacco richer in nicotine and made design changes to give smokers more puffs per cigarette, according to the analysis from the Harvard School of Public Health. The report expands on a landmark Massachusetts Department of Public Health study issued last August showing that the amount of nicotine that could be inhaled from cigarettes increased an average of 10 percent from 1998 through 2004.
The Harvard researchers, who corroborated the basic findings of the state study, wanted to determine why cigarettes were delivering more nicotine. The state report did not address causes .
"Industry says it's changed," said Greg Connolly, an author of the Harvard study and former director of the state health agency's Tobacco Control Program. "Yeah, they've changed -- maybe for the worse."
Philip Morris, the biggest US tobacco maker, released a statement last night challenging the Harvard study. The company said that nicotine levels of its top-selling Marlboro product have fluctuated, but that the rates in 1997 and 2006 were identical. The Harvard study, which was begun several months ago, did not include 2006 data.
The two other leading cigarette makers, Lorillard Tobacco Co. and R.J. Reynolds Tobacco Co., did not return phone calls yesterday seeking comment on the study.
The Harvard study relies on information supplied by the industry. A 1996 state law required cigarette makers to test the nicotine that could be inhaled from their products, and the state ordered the use of machines that simulate a typical smoker's puffing.
State regulations also require cigarette companies to provide other information to the Department of Public Health related to the delivery of nicotine, a substance that makes smoking more addictive and pleasurable. The state required companies to provide measures of nicotine concentration in tobacco, the number of puffs yielded by each cigarette, and the design of the filter.
The Harvard researchers used a sophisticated statistical analysis to examine data from the companies covering 1997 through 2005, two years more than the earlier state study. Like the Department of Public Health report, the Harvard study found that levels of inhalable nicotine during that period increased regardless of whether the cigarettes were menthol, full flavor, light, or ultralight.
The researchers used the company data to review possible causes for the increase and concluded that the single most important factor in the increased rates of inhalable nicotine was the amount of nicotine in the tobacco chosen for the cigarettes.
"It was systematic, it was pervasive, it involved all the manufacturers, and it was by design," said Dr. Howard Koh, an associate dean at the Harvard School of Public Health and an author of the study.
Another author said that the likelihood that the nicotine increase happened by chance was less than 1 in 1,000.
The study also said that the company data showed an increase in the number of puffs per cigarette, which the researchers said was probably due to a design change, but they could not determine the mechanism for that increase.
One activist expressed no doubt about what caused the changes .
"The tobacco industry is clearly looking to addict people quickly and to keep them heavily addicted by making it really, really hard for them to quit," said Diane Pickles, executive director of the advocacy group Tobacco Free Massachusetts, which was not involved with the study.
The Harvard researchers, as well as antismoking forces, said the study offers compelling evidence that the federal government should regulate tobacco much the way pharmaceuticals are controlled by the US Food and Drug Administration.
Senator Edward M. Kennedy is reviving long-stalled legislation that would give the FDA extensive authority over the sale, distribution, and advertising of tobacco products. A spokeswoman for Kennedy said last night that the senator intends to introduce the legislation in the next couple of weeks and conduct hearings shortly thereafter.
"Congress has been an accomplice in the travesty because of the success of the tobacco lobby in blocking real reform," Kennedy, a Massachusetts Democrat, said in a statement.
The Harvard researchers included a broader range of data than the state report in their search for the underlying cause of increases in inhalable tobacco. State officials said that in order to release their report as quickly as possible and to keep it accessible, they chose to limit the scope of their August study.
"We tried to do as simple an analysis as we possibly could," said Tom Land, a research analyst in the state's Tobacco Control Program. "We wanted as many people as possible to understand it."
In reports such as those generated by Harvard and the state, researchers look for trends while acknowledging that figures can fluctuate year to year. For instance, the Harvard researchers present data showing that inhalable nicotine in Marlboro brands generally trended upward from 1997 through 2005, although levels declined slightly in the last two years covered in the study.
In its statement, Philip Morris said, "There are random variations in cigarette nicotine yields, both upwards and downwards, and those variations are not consistent in either direction across reporting years."
Connolly and state health officials dispute that assertion, saying that their research shows a consistent upward trend.
The company also said, "Philip Morris USA agrees with the authors that cigarettes are addictive and harmful."
The Harvard researchers do not speculate in the study on how companies might have chosen tobacco with higher nicotine content, but veterans of the war on tobacco suggested possibilities.
They pointed, for example, to US government documents showing that in the 1980s one company, Brown & Williamson, bred tobacco in Brazil with twice the nicotine content of its standard product. Matt Myers, head of the Campaign for Tobacco-Free Kids, said that companies can also manipulate nicotine levels by choosing parts of the tobacco plant known to have high concentrations of the addictive ingredient.
"The evidence is clear that the tobacco companies are capable of and do carefully regulate the level of nicotine in their products," Myers said. "The consistent increase over a period of years can't happen by accident."
- 182 Health