Tag Archives: nicotine research

Parental Warning: Second-Hand Smoke May Trigger Nicotine Dependence in Kids

New study from Canadian researchers published in Addictive Behaviors

Parents who smoke cigarettes around their kids in cars and homes beware – second-hand smoke may trigger symptoms of nicotine dependence in children.

The findings are published in the September edition of the journal Addictive Behaviors in a joint study from nine Canadian institutions.

“Increased exposure to second-hand smoke, both in cars and homes, was associated with an increased likelihood of children reporting nicotine dependence symptoms, even though these children had never smoked,” says Dr. Jennifer O’Loughlin, senior author of the study, a professor at the Université de Montréal’s Department of Social and Preventive Medicine and a researcher at the Centre Hospitalier de l’Université de Montréal.

“These findings support the need for public health interventions that promote non-smoking in the presence of children, and uphold policies to restrict smoking in vehicles when children are present,” adds Dr. O’Loughlin, who collaborated with researchers from the Université de Sherbrooke, the Université de Moncton, the University of British Columbia, McGill University, Concordia University and the Institut national de santé publique du Québec.

Study participants were recruited from 29 Quebec schools as part of AdoQuest, a cohort investigation that measures tobacco use and other health-compromising behaviours. Some 1,800 children aged 10 to 12 years old, from all socioeconomic levels, were asked to complete questionnaires on their health and behaviours. Researchers also asked questions about symptoms of nicotine dependence and exposure to second-hand smoke.

Second Hand Smoke and Children“According to conventional understanding, a person who does not smoke cannot experience nicotine dependence,” says Mathieu Bélanger, the study’s lead author and the new research director of the Centre de Formation Médicale du Nouveau-Brunswick of the Université de Moncton and Université de Sherbrooke. “Our study found that 5 percent of children who had never smoked a cigarette, but who were exposed to secondhand smoke in cars or their homes, reported symptoms of nicotine dependence.”

Dr. O’Loughlin added that this inter-university investigation builds on previous findings: “Exposure to second-hand smoke among non-smokers may cause symptoms that seem to reflect several nicotine withdrawal symptoms: depressed mood, trouble sleeping, irritability, anxiety, restlessness, trouble concentrating and increased appetite.”

About University of Montreal Study on Second Hand Smoke

Contact: Sylvain-Jacques Desjardins
University of Montreal

About the study:

“Nicotine dependence symptoms among young never smokers exposed to secondhand tobacco smoke,” from Addictive Behaviors, was authored by Mathieu Bélanger (Université de Sherbrooke and Université de Moncton), Jennifer O’Loughlin (Université de Montréal and Centre Hospitalier de l’Université de Montréal), Louise Guyon (Institut national de santé publique du Québec), André Gervais (Direction de santé publique de Montréal), Jennifer J. McGrath (Concordia University), Chizimuzo T.C. Okoli (University of British Columbia) and Maninder Setia (McGill University).

On the Web:

Big Tobacco Companies Covered Up Radiation Dangers From Smoking

Tobacco companies have covered up for 40 years the fact that cigarette smoke contains a dangerous radioactive substance that exposes heavy smokers to the radiation equivalent of having 300 chest X-rays a year.

Internal company records reveal that cigarette manufacturers knew that tobacco contained polonium-210 but avoided drawing public attention to the fact for fear of “waking a sleeping giant”.

Polonium-210 emits alpha radiation estimated to cause about 11,700 lung cancer deaths each year worldwide. Russian dissident and writer Alexander Litvinenko died after being poisoned with polonium-210 in 2006.

The polonium-210 in tobacco plants comes from high-phosphate fertilisers used on crops. The fertiliser is manufactured from rocks that contain radioisotopes such as polonium-210 (PO-210).
The radioactive substance is absorbed through the plant’s roots and deposited on its leaves. 

People who smoke one-and-a-half packets of cigarettes a day are exposed to as much radiation as they would receive from 300 chest X-rays a year, according to research.

New health warning labels such as “Cigarettes are a major source of radiation exposure” have been urged by the authors of a study published in this month’s American Journal of Public Health. 

“This wording would capitalise on public concern over radiation exposure and increase the impact of cigarette warning labels,” the Mayo Clinic and Stanford University authors say.

Quit Victoria executive director Fiona Sharkie said Australian tobacco companies were not legally obliged to reveal the levels of chemicals contained in cigarettes. This made it difficult to know exactly how damaging PO-210 was and meant it was impossible to know what effect it had on other poisons contained in cigarettes.

“It (PO-210) is obviously highly toxic and we applaud any efforts to publicise the dangers,” she said. “But the industry needs to be better regulated before we can support specific warnings.” 

Inhalation tests have shown that PO-210 is a cause of lung cancer in animals. It has also been estimated to be responsible for 1% of all US lung cancers, or 1600 deaths a year.

The US authors analysed 1500 internal tobacco company documents, finding that tobacco companies conducted scientific studies on removing polonium-210 from cigarettes but were unable to do so.  “Documents show that the major transnational cigarette manufacturers managed the potential public relations problem of PO-210 in cigarettes by avoiding any public attention to the issue.”

Second Hand Smoke Laces the AirPhilip Morris even decided not to publish internal research on polonium-210 which was more favourable to the tobacco industry than previous studies for fear of heightening public awareness of PO-210.

Urging his boss not to publish the results, one scientist wrote: “It has the potential of waking a sleeping giant.” Tobacco company lawyers played a key role in suppressing information about the research to protect the companies from litigation.

The journal authors, led by Monique Muggli, of the nicotine research program at the Mayo Clinic, say: “The internal debate, carried on for the better part of a decade, involved most cigarette manufacturers and pitted tobacco researchers against tobacco lawyers. The lawyers prevailed.

“Internal Philip Morris documents suggest that as long as the company could avoid having knowledge of biologically significant levels of PO-210 in its products, it could ignore PO-210 as a possible cause of lung cancer.”

Source: William Birnbauer, Theage.com.au

There May be a Very Good Reason Why Coffee and Cigarettes Often Seem to go Hand in Hand

A Kansas State University psychology professor’s research suggests that nicotine’s power may be in how it enhances other experiences.

For a smoker who enjoys drinking coffee, the nicotine may make a cup of joe even better.

And that offer another explaination why smoking is so hard to quit.

“People have very regimented things they do when they smoke,” said Matthew Palmatier, assistant professor of psychology at K-State. “If you think about where people smoke or who they smoke with, you realize that it occurs in very specific places, often with a specific group of people.

Maybe it’s a reason why nicotine is so addictive — if you get used to having that extra satisfaction from things you normally enjoy, not having nicotine could reduce the enjoyment in a given activity.

“People may not be smoking to obtain a pleasurable drug state. They may be smoking in order to regulate their mood, and that effect could make nicotine more addictive than other drugs.”

Palmatier said much previous research on nicotine addiction has looked at the drug itself rather than the other factors he is studying.

“The approach we’re taking is out of left field,” he said. “But it seems to be one of the best explanations as to why people smoke.”

Palmatier has a grant from the National Institute on Drug Abuse to understand how this phenomenon can be used to better design tobacco addiction treatments, usually offered in stop smoking aids, like patches and pills. He began psychological research in addiction as a graduate student and later began researching the reinforcing effects of nicotine.

Coffee and Cigarettes“The big picture is trying to figure out why people smoke,” Palmatier said. “There are a lot of health risks, and the majority of smokers already know what they are. They want to quit but can’t. It’s not because nicotine is a potent drug; it doesn’t induce significant amounts of pleasure or euphoria. Yet, it’s just as difficult if not more difficult to quit than other drugs.”

At K-State, Palmatier studies rats that are allowed to self-administer nicotine by pushing a lever. The main source of light in their testing environment shuts off when the rats earn a dose of nicotine. After about a minute, the light comes back on to signal that more nicotine is available.

By manipulating this signal, Palmatier and his colleagues found that the rats weren’t really that interested in nicotine by itself.

“We figured out that what the rats really liked was turning the light off,” Palmatier said. “They still self-administered the nicotine, but they took more of the drug when it was associated with a reinforcing light.”

Palmatier and colleagues published a paper on their research in the August issue of Neuropsychopharmacology.

Palmatier has begun looking at how rats respond to sweet tastes after having nicotine. He said preliminary results show that nicotine has comparable effects on sweet tastes. That is, rats respond more for sugar-water solutions after getting nicotine.

“The taste aspect is really important because we can actually figure out how nicotine is increasing the subjects’ behavior,” Palmatier said. “If it makes a reward more pleasurable, then it may increase the palatability of a sweet taste.”

Palmatier said that a future phase of research would be determining whether nicotine can make unpleasant experiences more tolerable, helping explain why lighting up after a bad day at work can be tempting.

Contact: Beth Bohn
Kansas State University

Genetic Achilles Heel May Support Nicotine Addiction

Do genes play a role in tobacco addiction?

Recent studies suggest they may, particularly the CHRNA5 gene.

A University of Michigan press release notes a genetic variation suggests a finding that may help explain the path that leads from that first cigarette to lifelong smoking.

In the press release studies smokers and non-smokers to find if you have the less common rs16969968 form of the CHRNA5 gene and you smoke a cigarette you are more likely to get hooked.

Yet another reduction in the possible scope for free will.

Study on Genetics, Genes and Smoking

In a paper published in the September Issue of the journal Addiction, a multi-university collaborative team of researchers specializing in statistical genetics, gene analysis, and trait analysis reports an association between a variant in the CHRNA5 nicotine receptor gene, initial smoking experiences, and current smoking patterns.

The genetic and smoking data come from 435 volunteers. Those who never smoked had tried at least one cigarette but no more than 100 cigarettes in their lives, and never formed a smoking habit. The regular smokers had smoked at least five cigarettes a day for at least the past five years.

The regular smokers in the study were far more likely than the never-smokers to have the less common rs16969968 form of the CHRNA5 gene, in which just one base-pair in the gene sequence was different from the more common form. This kind of genetic variation is called a single nucleotide polymorphism or SNP.

Smokers were also eight times as likely to report that their first cigarettes gave them a pleasurable buzz.

“It appears that for people who have a certain genetic makeup, the initial physical reaction to smoking can play a significant role in determining what happens next,” says senior author and project leader, Ovide Pomerleau, a professor of psychiatry at the University of Michigan Medical School and founder of the U-M Nicotine Research Laboratory.

“If cigarette smoking is sustained, nicotine addiction can occur in a few days to a few months,” he adds. “The finding of a genetic association with pleasurable early smoking experiences may help explain how people get addicted — and, of course, once addicted, many will keep smoking for the rest of their lives.”Among those who ever try smoking this gene explains only part of the difference between those who become addicted and those who do not. Expect more discoveries of genes that contribute to the odds of getting addicted.

Achilles HeelWe are witnessing an acceleration of the rate of discovery of genetic factors that influence behavior. This acceleration in the rate of discovery will accelerate as DNA testing costs continue to drop. So expect to see many more reports of genes that influence behavior.

Source: Randall Parker, FuturePundit

Toenails Reveal All

Your toes tell it all, ladies.

Toenail clippings can provide evidence of tobacco exposure and help explain the risk of heart disease, at least in women, according to a unique study from the University of California-San Diego and Harvard University.

The medical researchers examined levels of nicotine in toenails of 905 women who were diagnosed with coronary heart disease from 1984 through 1998.

The women were among the 62,641 participants in the Nurse’s Health Study. Those with heart disease were randomly matched to two other participants by age and by the date that their toenails were collected.

The twenty percent of women who had the highest nicotine levels in their toenails turned out to have more than triple the risk of being diagnosed with heart disease as those whose levels put them in the lowest twenty percent. The risk remained significantly higher after the researchers took smoking into account, adjusting for the number of cigarettes smoked as well as exposure to second hand smoke.

Women's Toenails“Using toenail nicotine is a novel way to objectively measure exposure to tobacco smoke, and ultimately, to increase our understanding of tobacco-related illness, said Wael Al-Delaimy, of UC-San Diego’s department of family and preventive medicine, lead author of the study published this month in the American Journal of Epidemiology. “This would be especially helpful in situations where smoking history is not available or is biased.”

Source: Josh Goldstein, The Philadelphia Inquirer

Quitting Smoking is a Pack Behavior

Smokers tend to quit in groups, according to a new study.

One person who quits can have ripple effects across his or her entire social network, prompting others to kick the habit.

The New York Times offers this delightfully evocative explanation of how the process works:

As the investigators watched the smokers and their social networks, they saw what they said was a striking effect — smokers had formed little social clusters and, as the years went by, entire clusters of smokers were stopping en masse. So were clusters of clusters that were only loosely connected.

Dogs in a FieldStudy co-author Dr. Nicholas Christakis described watching the vanishing clusters as like lying on your back in a field, looking up at stars that were burning out. “It’s not like one little star turning off at a time,” he said. “Whole constellations are blinking off at once.”

Continue Reading About the Stop Smoking Ripple Effect

Researchers Identify Genetic Variant Linked To Nicotine Addiction

NIDA Researchers Identify Genetic Variant Linked To Nicotine Addiction And Lung Cancer – Variant Also Increases Risk For Cardiovascular Disease

Scientists have identified a genetic variant that not only makes smokers more susceptible to nicotine addiction but also increases their risk of developing two smoking-related diseases, lung cancer and peripheral arterial disease.

The research was supported by the National Institute on Drug Abuse (NIDA), part of the National Institutes of Health (NIH).

The study, published in the April 3 issue of the journal Nature, “highlights the advances that are being made in genetics research, which can now identify gene variants that increase the risk of complex bio-behavioral disorders,” says NIH Director Dr. Elias Zerhouni. “This finding will help us in our efforts to further reduce the scope and devastating consequences of cigarette smoking.”

“These results suggest for the first time that a single genetic variant not only can predispose to nicotine addiction but may also increase sensitivity to extremely serious smoking-related diseases,” explains NIDA Director Dr. Nora Volkow. “Additionally, it points to potential targets for new smoking-cessation medications that may be more effective at helping smokers to quit.”

The variant is closely linked to two of the known subunits of nicotine receptors, the sites on the surface of many cells in the brain and body that can be bound by nicotine. When nicotine attaches to these receptors in the brain, there are changes in cell activity that results in its addictive effects.Carriers of this genetic variant are more likely than noncarriers to be heavy smokers, dependent on nicotine, and less likely to quit smoking. “The variant does not increase the likelihood that a person will start smoking, but for people who do smoke it increases the likelihood of addiction,” says Dr. Kári Stefánsson, the study’s principal investigator and chief executive officer of deCODE Genetics, a biopharmaceutical company based in Reykjavik, Iceland.

The variant was identified through a technique known as genome-wide association, in which DNA samples (from more than 10,000 Icelandic smokers) were analyzed for the presence of more than 300,000 genetic markers. Subsequent investigation showed that carriers of the variant strongly associated with nicotine dependence were also at increased risk for two smoking-related diseases, peripheral arterial disease and lung cancer. The findings were replicated in populations from five European countries and New Zealand. The researchers estimate that the variant explains 18 percent of cases of lung cancer and 10 percent of cases of peripheral arterial disease in smokers.

Nicotine addictionThe same variant was identified as one that increased risk for lung cancer in two other articles appearing in the April 3rd, 2008, issues of Nature and Nature Genetics, partially funded by two other NIH institutes–the National Cancer Institute and the National Human Genome Research Institute.

For more information on Smoking/Nicotine: http://www.drugabuse.gov/DrugPages/Nicotine.html

The National Institute on Drug Abuse

The National Institute on Drug Abuse is a component of the National Institutes of Health, U.S. Department of Health and Human Services. NIDA supports most of the world’s research on the health aspects of drug abuse and addiction.

The Institute carries out a large variety of programs to inform policy and improve practice. Fact sheets on the health effects of drugs of abuse and information on NIDA research and other activities can be found on the NIDA web site at http://www.drugabuse.gov.

The National Institutes of Health

(NIH) – The Nation’s Medical Research Agency – includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services.

It is the primary Federal agency for conducting and supporting basic, clinical and translational medical research, and it investigates the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit http://www.nih.gov.