Movies, Teenagers & Smoking

The major tobacco companies have long paid hefty fees to movie production companies in order to have their brands conspicuously “placed” within popular films.  It is no coincidence when the hero of your favorite film pulls out a cigarette from a Marlboro box and lights up onscreen.  Tobacco companies would have you believe that the millions of dollars they spend each year on product placement in films directed at teens and young adults have no direct impact on teen smoking rates.  Likewise, the heavy targeting of magazines that appeal to teens and young adults by tobacco companies represents annual investments of tens of millions of dollars.  One would intuitively presume that these huge ongoing investments in advertising by Big Tobacco must serve some useful capitalist purpose….

A new study published in the current issue of the journal Lancet took a prospective look at the correlation between exposure to smoking in movies and the new onset of smoking in adolescents.  A total of 3,547 adolescents, aged 10 to 14 years, enrolled in the study.  All of these students were non-smokers at the time of their entry into the study.  The teenagers were assigned to watch 50 randomly selected movies from a larger movie library, each featuring varying levels of smoking behaviors onscreen.  The teenagers were re-contacted 13 to 26 months later to determine the interval incidence of smoking.  Overall, 10% of the students had initiated smoking during the course of the study.  Among the group of students who watched movies depicting the greatest frequency of smoking behaviors onscreen, 17% had, themselves, become smokers.  Among the students who viewed a collection of 50 movies with the least amount of smoking activity onscreen, only 3% had taken up smoking themselves.  After controlling for other possible factors that might have contributed to the initiation of smoking behaviors, the study determined that exposure to the highest levels of onscreen smoking activity in popular films was associated with a nearly three-fold increase in the likelihood of initiation of adolescent smoking.  Interestingly, the pro-smoking effect of onscreen smoking activity was most potent among teens whose parents were non-smokers.  In this group of students, fully 52.2% initiated smoking following exposure to 50 films with the greatest amount of smoking activity onscreen.  These results were statistically significant, and only confirm what the advertising departments of tobacco companies have known for decades.

Spinal Manipulation for Low Back Pain

Many people seek therapies that do not involve the use of drugs or surgery for various illnesses.  One of the most common ailments among adults is chronic low back pain.  Spinal manipulation, as performed by massage therapists, chiropractors and osteopaths, is a popular approach to treating chronic musculoskeletal back pain.  Unfortunately, there have been very few scientific studies that have objectively evaluated these non-traditional therapies in comparison to orthodox allopathic remedies. 

A new study in the Annals of Internal Medicine looked at 39 previously published randomized clinical trials of spinal manipulative therapy, and performed an exhaustive comparative analysis of these studies using a technique called meta-analysis.  Meta-analysis is a complex statistical process that “equalizes” the conditions of multiple studies so that their results can be directly compared with each other. 

The 39 studies included in this analysis compared spinal manipulative therapy with traditional allopathic therapies, including physical therapy, analgesics, back exercises and general physician care.  In a case where the cup may be either half-full or half-empty, depending upon your perspective, the analysis revealed that spinal manipulative therapy was no better than traditional allopathic remedies in terms of relief of symptoms.  If you are a fan of manipulation, then you might be inclined to view this study as confirming that manipulation is as good as other modes of therapy, including medications that you might wish to avoid taking.  If you are not predisposed to having your back torqued and kneaded, then you could interpret this study as confirming that spinal manipulation does not offer anything that a hot shower and a couple of ibuprofen tablets can’t take care of.  Either way, this is an interesting study that puts a little science behind the spinal manipulation vs. allopathic therapy debate.

Your Personality & the Risk of Cancer

Some healthcare providers will swear to you that patients with certain diseases seem to have distinctive personality traits.  So it is with many types of cancers.  This has raised the question as to whether or not a person’s baseline personality type might predispose them to developing certain types of cancer.  High levels of anxiety, neurosis and depression have often, at least anecdotally, been linked to an increased incidence of certain cancers.  However, there has never been a well-designed scientific study to look at possible associations between personality types and the risk of developing cancer.  A new study in the current issue of the Journal of the National Cancer Institute sheds some scientific light on this controversial issue. 

A total of 30,277 Japanese volunteers entered this study, and underwent extensive personality assessments using standardized and previously validated questionnaires.  All volunteers were followed for an average of 7 years to assess for the development of cancer.  Potentially confounding factors, such as sex, age, educational level, tobacco use, alcohol use, body mass index and family history of cancer, were also taken into consideration and adjusted for.  Fortunately, no association between personality features and the risk of developing cancer were identified in this large-scale study.  The study’s authors surmise that the apparent increased incidence of neurotic personality subtypes among cancer patients is more likely to be secondary to their diagnosis of cancer, and not the other way around.

Working the Night Shift & Your Risk of Cancer

Most people who regularly work night shifts will tell you that they never really become fully accustomed to their nocturnal lifestyles.  Try as we might, the human species, as with the majority of other earthly life forms, is designed to sleep by the silvery light of the moon. 

Melatonin is an interesting hormone that is secreted by a tiny pea-sized gland deep in the brain, the pineal gland, and is now known to play an important role in our daily sleep-wake circadian cycle.  It is primarily secreted at night, but its release by the pineal gland is inhibited by exposure of the eyes’ retinas to light.  Melatonin, in addition to its role in sleep regulation, is a powerful anti-oxidant, and has previously been shown to have anti-cancer effects, particularly against colorectal cancer cells grown in the laboratory.  Previous studies have also suggested an increased risk of breast cancer among women who frequently work night shifts.  A new study, also published in the current Journal of the National Cancer Institute, examines rotating night shift employment and the risk of developing colorectal cancer.  The study evaluated the incidence of colorectal cancer among 78,586 nurses who participated in the landmark Nurses’ Health Study from 1988 through 1998.  Altogether, 602 cases of colorectal cancer were diagnosed during the course of this study.  For the purposes of this study, the women volunteers were divided into three groups for analysis: women who never worked rotating night shifts, women who had worked rotating night shifts for 1 to 14 years, and women who had worked such rotating shifts for 15 or more years.  The study found that the women in the 1 to 14-year night shift group experienced the same colorectal cancer risk as women who never worked night shifts.  However, the nurses who spent 15 or more years working rotating night shifts experienced a 35% increase in the relative risk of developing colorectal cancer.  Whether this observation is directly related to chronic suppression of melatonin production, or to other factors, is not clear as the study did not actually measure melatonin levels.  Such a study would be the next logical step in order to ascertain what, if any, linkage there is between chronic melatonin suppression and colorectal cancer risk.  One arm of such a study should also include melatonin supplementation in women who chronically work rotating night shifts.  In any case, it does appear that working the night shift for 15 or more years may increase your risk of developing colorectal cancer.

Dr. Robert A. Wascher