Saturday, November 30, 2013

Chronic smoking accelerates atrophy of the hippocampus, a key memory structure in the brain.

Most people are aware that our memory abilities decline with aging, but a recent paper in the journal Drug and Alcohol Dependence reported that chronic cigarette smoking seems to strikingly accelerate shrinkage of a key memory structure in the brain, the hippocampus (Figure (MRI image), red circles).

The study also reported that hippocampus shrinkage in smokers is associated with smoking severity, as measured in pack-years, and that certain types of memory decline, including auditory-verbal memory (the ability to remember sounds and words) and visuospatial learning and visuospatial memory (the ability to learn and remember spatial relationships among elements in view, required to navigate through one’s environment), are associated with hippocampal volumes in smokers and nonsmokers. Thus, chronic smokers likely experience greater deficits in these key memory capabilities than nonsmokers.

Over the age range studied (20-70 years old), hippocampus volume declined by ~12% in nonsmokers and by ~30% in smokers, meaning that chronic smoking more than doubled the rate of hippocampal volume loss occurring as a consequence of normal aging.

The study authors noted that the severity of hippocampal volume loss among older smokers in their study was on par with the severity of volume loss found in people with mild cognitive impairment, which could in part explain the increased risk among chronic smokers for developing dementias such as Alzheimer’s Disease.

Many smokers resolve to quit smoking as a New Year’s resolution. If you smoke, the findings from this study provide yet another reason to seriously consider trying to quit smoking during this holiday season.

CPDDBLOG welcomes CPDD member's thoughts on these issues.

Monday, September 30, 2013

Should E-cigarette sales be regulated? Most Attorney Generals think so.

This past week, Attorney Generals from 37 states, Guam, Puerto Rico, and the US Virgin Islands urged the US Food and Drug Administration (FDA) to regulate E-cigarette advertising, formulation, and sales to minors.

Their case laid out in their letter (PDF) noted that E-cigarette sales are growing “exponentially”, that there are no age restrictions on sales or advertising (unlike regular cigarettes), that E-cigarettes are marketed as safe alternatives to regular cigarettes, and that they contain flavorings that are “appealing to youth”.

While E-cigarettes appear to be effective for reducing nicotine withdrawal symptoms in smokers intending to quit, for reducing the numbers of cigarettes smoked by smokers not intending to quit, and for reducing exposure to carcinogens and toxicants found in regular cigarettes, side effects reported in online forums suggest that E-cigarettes induce up to 4 times as many negative as positive side effects.

Further, E-cigarette retailers offer many candy-like flavored nicotine solutions (e.g., cotton candy and bubblegum) that seem designed to initiate E-cigarette use by children, rather than help them quit smoking.

Perhaps more importantly, a recent report analyzing nicotine content in E-cigarette solutions from several brands suggests that each E-cigarette (with nicotine tank/cartridge volumes ranging from 1-6 ml) contains amounts of nicotine exceeding lethal doses in children (10 mg) and adults (40-60 mg) (Figure).

The hazard seems even greater for E-cigarette liquid refills sold in volumes ranging from 10-500 ml, which if consumed orally or absorbed transdermally through the skin, can far exceed lethal nicotine doses even for adults (67 to 9950 mg).

Thus, the call for E-cigarette regulation by Attorney Generals seems very timely.

CPDDBLOG welcomes CPDD member's thoughts on these issues.

Saturday, July 27, 2013

Public Comments Sought by FDA on Whether Menthol Cigarettes Should be Regulated

As part of an effort to determine whether and how to regulate tobacco product sales, this past week, the US Food and Drug Administration (FDA) opened a 60-day comment period to obtain information from the public on whether menthol cigarettes should be regulated.

The FDA also released an independent report entitled “Preliminary Scientific Evaluation of the Possible Public Health Effects of Menthol Versus Nonmenthol Cigarettes”. The report, in PDF form, is available for free here.

The report noted that menthol cigarettes constitute about 25% of cigarette sales in the US and that cigarette smoking leads to more than 400,000 deaths annually in the US alone. Globally, the World Health Organization reports about 6 million deaths annually caused by cigarette smoking, a figure expected to rise to more than 8 million per year by 2030.

The FDA report analyzed existing research to determine whether there are differences between menthol and nonmenthol cigarettes in terms of smoking chemistry/toxicity, physiological effects, biomarkers of exposure, patterns of smoking, consumer perceptions, smoking initiation and progression to regular use, nicotine dependence, ability to quit, and disease risk.

Existing scientific evidence included in the report does not support major differences between menthol and nonmenthol cigarettes in a number of key measures, including smoking biomarkers, toxicity, consumer perceptions, or disease risk. However, the report concluded that menthol cigarettes induce different physiological responses, are associated with earlier initiation and progression to regular use, induce greater smoking dependence (menthol smokers are more likely to report smoking their first cigarette within 5 minutes of waking up), and make it harder to quit smoking than nonmenthol cigarettes, especially among African American smokers. 

Recent research may shed some additional light on these conclusions.

A 2013 analysis of data from the National Health and Nutrition Examination Survey (NHANES, 1999-2010) determined whether differences existed between menthol and regular cigarette smokers in blood or urine toxic biomarkers of smoking. Data from more than 4,600 adult smokers (1,393 menthol cigarette smokers) showed that menthol smokers exhibited significantly higher blood cadmium concentrations, although upon stratification of the sample by race, the association was found to be significant only in smokers who were White. The report also suggested that there may be ethnic differences in effects of menthol cigarette smoking, as among African Americans, menthol cigarette smokers exhibited higher blood lead levels and among Mexican Americans, menthol cigarette smokers exhibited higher urine NNAL (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol) levels. This study provides new evidence that there may be differences in toxic biomarker levels between menthol and nonmenthol cigarette smokers.

With regard to marketing of menthol cigarettes, a large longitudinal 2013 study of nearly 1,200 6th–9th graders in a racially diverse California school district concluded that nonsmokers who recognized the Newport brand (a menthol cigarette) were 50% more likely to initiate smoking within 12 months, regardless of race (Figure). By contrast, recognition of Camel menthol or Marlboro nonmenthol brands was not associated with smoking within 12 months, leading the authors to propose that point of sale advertising of Newport brand cigarettes be controlled. A PDF of the full report can be found here. This study provides new evidence that consumer perceptions, actually, potential consumer perceptions, can lead to smoking initiation differences.

As more studies emerge comparing effects of menthol to nonmenthol cigarettes, it seems clearer that menthol cigarettes are associated with greater danger for early smoking initiation and increased exposures to toxic compounds.

Prior CPDDBLOG coverage of the menthol cigarette issue can be found here, here, here, and here.

CPDDBLOG welcomes CPDD member's thoughts on these issues.

Friday, June 28, 2013

CPDD Annual Meeting Public Policy Forum: Part II: Considerations for Regulating Marijuana to Achieve Public Objectives

The second part of the Public Policy Forum focused on marijuana regulation, now that it has been legalized in Colorado and Washington State and now that there are moves toward legalizing it in other jurisdictions, including at the federal level.

Drs. Beau Kilmer and Rosalie Pacula, Co-Directors of the Rand Drug Policy Research Center (Rand Corporation, Santa Monica, CA), outlined a number of considerations relevant to regulating marijuana sales that could help achieve public health objectives.  They also described the current regulatory climate in Colorado and Washington State.

Dr. Kilmer began his presentation by describing design considerations for regulating marijuana sales, including Production, Profit motive, Promotion, Prevention, Potency, Price, and Permanency, or as he referred to these issues, the "7 P's".  He indicated that Colorado and Washington State have focused primarily on taxation policy but have yet to study other relevant issues and how regulations could be instituted to promote public health objectives.

He noted that with legalization, marijuana Production (including delivery and sales) risks will be substantially reduced, and thus it is anticipated that the free market price of marijuana will decline.  This could both increase the numbers of users and increase heavy marijuana use.  If price controls are not instituted and Profits are allowed to be maximized, this also could stimulate marijuana sales and use.  In terms of Promotion, if for-profit companies are allowed to enter the market, countering their marketing activities could be difficult based on free speech issues, and increased marketing likely would result in increased use.  And, currently, there are no plans articulated for Prevention efforts, which again could contribute to increased initiation and chronic use.

Since the tetrahydrocannabinol (THC) content in street Mexican marijuana currently is on the order of 4-8%, much lower than THC levels in marijuana available in dispenseries (10-25%), if THC Potency is not regulated, users may be exposed to THC levels much higher than to which they are accustomed, which could result in unanticipated side effects or other health consequences.  Pricing considerations can have important effects on initiation, as studies suggest that each 10% decline in price results in a 3% increase in initiation.  The degree of Permanency of regulations also may be critical, as if initial policies are flawed and result in suboptimal public health outcomes, a failure to include escape or sunset clauses might make it very difficult to revise regulations down the road.  Dr. Kilmer asserted that all of the 7 P's should be included in any serious discussion of marijuana regulatory policy.

Dr. Pacula followed by again stating that many of these issues are not being discussed or considered by policymakers.  She indicated that if there is a desire to protect those who could be harmed by having increased access to marijuana, that it is important to have a good policy discussion.

She pointed out that we already have good models for alcohol and tobacco regulation that enable their legal use by adults while reducing harm, and these standard practices could be modified and applied to regulate marijuana.  The Rand Corporation convened a meeting in February 2013 both to identify helpful alcohol and tobacco control regulations and to develop consensus public health and other goals for marijuana regulation.

The consensus public health goals for marijuana that emerged from the meeting were to:
- prevent youth access and use
- prevent intoxicated driving
- regulate potency
- minimize use along with alcohol

Regulatory methods that could help attain those goals include setting prices high (to discourage consumption) but not so high as to foster a black market, as well as having either a governmental monopoly option that oversees sales and marketing activities or a strong licensing system that could regulate the types and densities of sales outlets to limit availability (reducing access) and limit competition (to preserve higher prices).

She also noted that as more jurisdictions legalize marijuana, that other public health issues may emerge including clean air concerns (tobacco smoking laws may not apply) and drugged driving concerns (as there is no rapid field test capable of measuring breath or blood THC levels and even if there were, there is no consensus on the threshold level for THC intoxication).

Dr. Pacula finished her presentation by reiterating that marijuana policy aims need to focus on a broader array of questions than taxation and must include public health objectives, and that now is the time to begin discussing these issues.

CPDDBLOG welcomes CPDD member's thoughts on these issues.

Coverage of Part I of the Public Policy Forum can be found here.