Levels of nicotine continue to creep up in the smoke of most major cigarette brands by more than one percent a year, says a statistical analysis of nine years of data reported by tobacco companies to the Commonwealth of Massachusetts.
The report confirms preliminary calculations released in September by the state health department and extends the assessment to include the likely mechanisms. The nicotine upswing detected by smoking machines appears to be caused by certain design changes in the cigarette—particularly, higher concentration of the drug in the tobacco and more puffs per cigarette as determined by the machine.
The result is increased potential for addiction. The researchers do not know the actual effect on smokers. Other studies have shown cigarettes are designed so that smokers can adapt to different nicotine levels and suck in as much as they please. The findings, say the HSPH researchers who conducted the study, highlight the need for federal regulation of tobacco products and more detailed studies, including data on the actual effect on people.
“The smoker can extract more nicotine, thus making it potentially more addictive, but not until we have actual exposure data can we conclude that higher exposures have occurred,” said co-author Gregory Connolly, director of the HSPH Tobacco Control Research Program.
Data May Tar IndustryThe researchers issued a white paper and posted it to the web last month prior to its upcoming publication in the journal Tobacco Control. They wanted to make the data publicly available for anticipated Congressional hearings about legislation to give the U.S. Food and Drug Administration legal authority to regulate tobacco products.
“We have an obligation to take science and translate it to the best of our ability to Americans and policymakers,” Connolly said. “Science has to play an important role in the construction of policy.”
So far, cigarettes have been exempt from every major national health and safety law passed since the first U.S. Surgeon General report in 1964 officially condemned cigarette smoking as a cause of cancer and other serious diseases, Connolly said. The list includes the Federal Hazardous Substances Act, Consumer Product Safety Act, and the Controlled Substances Act. The most recent Surgeon General report points out that cigarettes cause diseases in nearly every organ of the body.
Groundbreaking state legislation generated the data for the study by Connolly and his colleagues. For 10 years, the first-in-the-nation Massachusetts Tobacco Product Disclosure Law has required annual nicotine content and nicotine yield disclosures. The yearly reports are a remnant of the comprehensive state Tobacco Control Program. The prevention program helped slash adult tobacco consumption by half from 1992 to 2003 before it was gutted and the supporting cigarette taxes and tobacco industry legal settlement payments were diverted to other services, according to a postmortem overview in the Sept.–Oct. 2005 Public Health Reports.
Two of the current study’s co-authors oversaw the state program during its heyday. Connolly, a former director of the Massachusetts Department of Public Health’s Tobacco Control Program, spearheaded the “Make Smoking History” campaign. Howard Koh, HSPH associate dean for public health practice, was the state commissioner of public health.
“The analysis represents a crucial story for me personally,” Koh said. “We knew we had a rare opportunity to shine light on areas that are usually shrouded in secrecy when we started collecting the data [in 1997]. Now we find these outcomes are by design.” The health department’s September calculation was the first such effort to crunch those numbers for public consumption, he said, and the HSPH study went much further.
Tobacco Company ObjectionsThe researchers began their inquiry after Philip Morris USA, which markets the dominant Marlboro brand family, challenged the state findings that Marlboro delivered more nicotine in 2004 as compared to 1998. The company attributed any fluctuations to “year-to-year variations [that] occur as part of the normal processes of growing tobacco and manufacturing cigarettes.” (The press release also reiterated the company’s support for FDA regulation of its product.)
Machine yields do not equal exposure, agree Connolly, Koh, and fellow HSPH researchers Hillel Alpert and Geoffrey Ferris Wayne. But the researchers also wanted to know what a more detailed analysis would tell them about nicotine levels in smoke and what might be driving any trends.
Despite their state legacy, the researchers had to pressure the health department with a freedom-of-information request to acquire the public records filed by tobacco companies each year. Massachusetts requires a more intensive set of parameters for measuring nicotine yield than does the Federal Trade Commission. Known as the MA (Massachusetts) method, the criteria aim to better simulate a more modern style of smoking. A machine must take a 45 milliliter puff every 30 seconds that lasts for two seconds. Fifty percent of the ventilation holes in the cigarette must be blocked, and it must be smoked down to a certain butt length.
A statistical multivariate analysis showed that the increase in nicotine was a real trend over time, not a random variation, Alpert said. “We demonstrated that distinct changes in the design of cigarettes, particularly the increased nicotine concentration in tobacco, were responsible for the increased nicotine yield,” he said.
Objection OverruledThe HSPH researchers also investigated the Philip Morris claim that the Marlboro brand family stood apart from any general rise in cigarette nicotine levels. “We found no evidence that the trend in Marlboro was different from other brands,” Alpert said. After the HSPH report covering 1997–2005 was released, Philip Morris countered with another press release criticizing the researchers for not including 2006. Alpert ran the analysis again with 2006 data and found the same statistically significant trend of increasing nicotine levels in smoke.
Even if the trend changes, the findings need to be interpreted with caution, said David Hammond, a researcher at the University of Waterloo in Ontario, Canada. “If there’s one thing we’ve learned, machine smoking of cigarettes says nothing about what people get,” he said. “Smokers of the same product inhale significantly different amounts of nicotine from the same cigarettes. We should not lose sight of the fact that all of the cigarettes tested in this study contain ample nicotine to promote and sustain addiction. Modest increases and decreases in nicotine levels do not alter this fact.”
The findings are bad news to Taru Kinnunen, assistant professor of oral health policy and epidemiology at HSDM, who conducts clinical trials on the best way to treat tobacco dependence in women. “The smoking population is becoming harder to treat in the U.S. and in Western cultures with good tobacco control implemented,” she said. “My clinical sense is that people are more addicted and harder to treat.”
