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Freebase nicotine increases addictionBupa investigative news - 6 August 2003
Smoking is one of the leading causes of death in the UK and is known to be an addictive habit. According to new research from America, some cigarettes may be more addictive than others because they release more of a particularly potent form of nicotine, called freebase nicotine. So how does freebase nicotine work, and are some cigarettes more difficult to give up than others? What were the headlines?Details of the smoking research, conducted at the Oregon Health and Science University (OHSU) in Portland, America, appeared in a number of UK newspapers and websites. The reports appeared under headlines such as, "The tobacco additives that keep you hooked", "'Freebase' nicotine - why some cigarettes may be more addictive", and, "'Super-addictive' cigarette probe". With smoking being one of the major health issues in today's society, the majority of the reports offered a detailed examination of the research and the way in which freebase nicotine can be more addictive. What is the bigger picture?OHSU lead researcher James F Pankow, PhD, professor of environmental and biomolecular systems, explained that the key difference between freebase nicotine and normal nicotine lies in the speed with which the different forms reach the brain and take effect. According to James Pankow, normal nicotine is carried into the lungs in a "solid" form on the billions of particles that make up the smoke. This is then absorbed into the bloodstream and carried to the brain where it takes effect. In contrast, freebase nicotine is released as a gas from the cigarette and is absorbed much more quickly into the bloodstream, causing an almost instant "hit" of nicotine to the brain. The brain soon becomes addicted to obtaining regular "hits" of nicotine and it is generally believed that the faster the "hit" is delivered, the more quickly a person becomes addicted. The difference between normal nicotine and freebase nicotine is similar to the difference between ordinary cocaine and crack cocaine. For both crack cocaine and freebase nicotine, the molecules of the drugs are "freebased" by having hydrogen ions stripped off them, which allows them to vaporise easily into a gas. This gas then passes almost instantaneously into the bloodstream and to the brain, causing a sudden "hit" or rush. James Pankow believes that the increased speed of the "hit" as crucial. "Since scientists have shown that a drug becomes more addictive when it is delivered to the brain more rapidly, freebase nicotine levels in cigarette smoke are at the heart of the controversy regarding the tobacco industry's use of additives like ammonia and urea, as well as blending choice in cigarette design," he said. Levels of freebase nicotine in cigarettes may be raised by adding chemicals which can strip away hydrogen ions from nicotine molecules, such as ammonia. To investigate how much freebase nicotine was released by each cigarette, research was carried out by researchers from the Oregon Health and Science University in Portland, America. The results have been published on the website of the American Chemical Society's journal, Chemical Research in Toxicology. Using a controlled laboratory, involving a special smoking device and a gas chromatograph-mass spectrometer (GC-MS), the team collected and analysed the smoke from 11 brands of American cigarettes. The cigarettes were tested against a research-only cigarette with 1 per cent freebase nicotine that was used as a reference. The percentage of freebase nicotine released in the first three puffs of smoke from each cigarette, along with the amount then released in their remaining smoke, were measured and comparisons were made between brands. The researchers discovered that the amount of freebase nicotine varied considerably between products, ranging from 1.6 per cent up to 36 per cent. "We believe that this study is a major step forward in understanding how addictive nicotine is delivered by tobacco smoke. We found big differences in the percentages of freebase nicotine among 11 commercial cigarette brands," said James Pankow. Adding ingredients to tobacco to make cigarettes more pleasurable and addictive is by no means a new trend. A paper by Derek Yach and Douglas Bettcher, published in the journal Tobacco Control in 2000, pointed out that, "tobacco companies also devoted decades of research to studying the alteration of the chemical forms of nicotine to increase the percentage of freebase nicotine delivered to the smoker. Tobacco company documents indicate that this can be achieved by raising the pH of smoke by the use of additives, most notably, ammonia."
What does this mean?Naj Dehlavi, spokesperson for Action on Smoking and Health (ASH), told Bupa, "We're not at all surprised by the research, although it is a worrying trend." The research only looked at US brands where there are no guidelines on what can and cannot be added to cigarettes. But Naj Dehlavi believes it's likely to be a similar situation in the UK. In the UK there is a list of permitted ingredients tobacco companies may add to their cigarettes. The permitted list is published by the Department of Health (available at http://www.ash.org.uk/html/regulation/html/ukadditivesshort.html) and runs to over 600 additives. The Tobacco Manufacturers' Association commented that, "UK cigarettes are different from American cigarettes and abide by the permitted list of additives. As this was an American study, it's difficult to make comparisons." But Chris Proctor, head of science and regulation at British American Tobacco (BAT), expressed interest in the study, especially as it used a new technique and a novel sampling method. However, he said it's hard to know if the results apply to the UK and "the chances are that it's nothing to do with the ingredients, but something to do with tobacco types." What's more, when it comes to the notion of added ingredients to make cigarettes more addictive, Chris Proctor believes the research fails to make a logical connection. "Although the paper itself doesn't address this, a lot of the quotes Pankow gave and some of the media reports have talked about ingredients that are added to cigarettes to make them more volatile and therefore be more addictive," he told Bupa. "But if you look at the chart that Pankow gives in his study, the top brand for what he calls effective pH - i.e. more freebased - is a brand called American Spirit. Yet American Spirit is a brand that has no ingredients - they sell it on the basis that it's ingredient free. The one that's at the bottom, GPC, is a brand from our company, Brown and Williamson, and that does contain ingredients, including diammonium phosphate. If his measuring technique is correct, then there's no logical connection between his ingredients and the pH," he explained.
What does this mean to me?"Nicotine in itself, without any additions, is one of the most highly addictive substances known," said Naj Dehlavi. "The Royal College of Physicians say it's as addictive as cocaine or heroin, and that's without the additives." Bupa's Dr Virginia Warren had particular concerns about the effects of smoking on children. "Professor Pankow's observations about freebase nicotine are worrying when you think about adults. When you consider them alongside the output of the DANDY study conducted in Massachusetts by Dr. DiFranza and his colleagues, which showed how easily teenagers could become addicted to nicotine, they are frightening. Society needs to consider how it might protect these children - which we have not been doing well. Young people's - particularly girls' - smoking has been becoming more, not less, common in recent years." In the DANDY study, the addictive effects of smoking on children aged 12 and 13 were investigated. The research, published in 2002 by Dr. Joseph DiFranza, showed that 40 per cent of those children who'd ever smoked (even just a puff) showed signs of addiction, while 53 per cent of those children who inhaled had signs of addiction. With children being more susceptible than adults, it's a worrying situation. According to Cancer Research UK, 120,000 people a year die as the result of smoking and it's the single most preventable cause of early death. It's also one of the leading causes of cancer, heart disease and chronic lung disease. The Department of Health advise that the most practical way to avoid the risks associated with smoking is to not smoke or stop smoking. Their Giving up Smoking website offers help for quitters and assistance with managing cravings is available through nicotine replacement therapy (NRT) and bupropion (Zyban). SummaryIn its normal form nicotine is addictive and it is believed that freebase nicotine is even more addictive. While some cigarettes may be less addictive than others, ultimately the best way to avoid the issue is to not smoke or stop smoking. Links for more information
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