Health Briefs

June 21, 2002

Update on Smoking & Disease
The International Agency for Research on Cancer (IARC), an agency of the World Health Organization, has released the preliminary results of its exhaustive review of more than 3,000 tobacco–related health studies published since 1986.  The risks of smoking-induced cancers other than lung cancers were specifically evaluated by the IARC, and the findings in this regard were surprising and sobering.  Secondly, while there is an enormous body of data that has already confirmed the link between active smoking and diseases such as lung cancer, emphysema (COPD) and coronary artery disease, the link between passive exposure to tobacco smoke and lung cancer has been somewhat less conclusive so far.  Based upon statistical analysis of lung cancer trends, it has previously been estimated that 50,000 lung cancer deaths occur each year in the United States as a consequence of exposure to second-hand tobacco smoke. 

The IARC analysis concludes that half of all active smokers will be killed by totally preventable diseases caused by smoking.  Half of these tobacco-induced deaths, involving fully 25% of all smokers, will occur between the ages of 35 and 69 years, essentially robbing these smokers of 20-25 years of life.  Although tobacco accounts for millions of cancer deaths around the world, far more smokers will die of non-cancer lung disease, cardiovascular disease and stroke.  Sadly, virtually all of these millions of deaths will be preventable.  While lung cancer is the most common cancer associated with tobacco, the IARC study confirms that cancers of the stomach, esophagus, liver, cervix, pancreas, bladder, kidney, throat, sinuses and bone marrow (myeloid leukemia) also occur significantly more often in smokers when compared to non-smokers.  In the presence of other known risk factors for some of these cancers, the concomitant use of tobacco further increases the risk of cancer above the level incurred by the non-tobacco risk factor(s). 

Although more than 90% of all lung cancers are caused by cigarette smoking, the increased risk of tobacco-induced cancer is not limited to cigarettes alone.  Cigar and pipe smoking also increase the risk of cancers of the lung, as well as cancers of the head and neck, and other sites.  Tobacco does not discriminate between men or women either, and causes disease at equal rates among smokers of both genders.  For those looking for some “good news” about smoking and the risk of cancer, the IARC report indicates that smoking does not appear to increase the risk of cancers of the prostate or uterus and, possibly, of the breast.

The most effective approach to tobacco-induced disease is to never begin smoking.  For smokers who quit while still in their early 30s, the IARC analysis suggests that the majority of tobacco-related disease risks will be nullified over the passage of time.  However, even older smokers can still significantly reduce their risk of tobacco-induced diseases by quitting.

Now, on to the issue of second-hand smoke.  The tobacco industry (and many smokers) have often claimed that there is no compelling scientific evidence that exposure to second-hand smoke can cause lung cancer or other serious disease.  Based upon the IARC’s comprehensive review of all available data, involving millions of subjects since 1986, there is significant evidence that second-hand smoke exposure does indeed substantially increase the risk of lung cancer (by about 20% when compared to non-smokers who are not chronically exposed to second-hand smoke).

Tobacco has been shown, repeatedly, to be the most common cause of preventable disease and death in the developed world, and in many areas of the developing world as well.  In the United States alone, 170,000 new cases of lung cancer will be diagnosed in 2002, and 155,000 people will die of this preventable disease.  Lung cancer alone accounts for nearly 40% of cancer deaths in this country.  Quite simply, at least half of all cancer deaths, and many more millions of deaths caused by tobacco-induced non-cancer diseases, could be completely and permanently eradicated if everyone abstained from smoking.  This is, in public health terms, a staggering statistic….

Vasectomy & Prostate Cancer Risk
There has been some prior data that suggests at least a weak link between vasectomy and an increased risk of prostate cancer.  This has, understandably, made many men even more squeamish about undergoing surgical sterilization than the mere thought of this particular surgery alone.  In this week’s Journal of the American Medical Association, 923 men with prostate cancer and 1,224 randomly identified men without prostate cancer (controls) were evaluated, in New Zealand, for a history of prior vasectomy.  Despite correcting for differences in socioeconomic class, geographic region, religious background, and family history of prostate cancer, no significant increase in the risk of prostate cancer was identified in men who had previously undergone vasectomy.  The authors concluded that prior vasectomy, even after 25 or more years, does not appear to be linked with an increased risk of prostate cancer.  So, gentlemen, it appears that we will no longer be able to use that potential excuse in an attempt to persuade our mates that it is safer for them to undergo sterilization than it is for us….

Don’t Drink the Water (or the Salsa Either!)
A study in the current issue of the Annals of Internal Medicine might give some travelers pause before tucking into a basket of chips and salsa South of the Border.  Mexican-style tabletop sauces were analyzed in 71 restaurants located in Guadalajara, Mexico, and in 12 restaurants in Houston, Texas.  The sauces tested included green, red and pico de gallo salsas, as well as guacamole.  The sauces were all analyzed for the presence of the E. coli bacteria.  Fully two-thirds of the Guadalajara restaurants’ sauces were found to be contaminated with E. coli bacteria, while 40% of the Houston restaurants’ sauces were also determined to be contaminated.  However, among the contaminated sauces from Guadalajara, 18 of the 47 sauces containing E. coli bacteria were found to have strains of the bacteria known to cause gastrointestinal disease in humans.  None of the contaminated samples form the Houston restaurants were found to contain diarrhea-causing strains of E. coli, however.  Maybe you should bring your own salsa or guacamole during your next trip south….

Sex & Violence and Advertising: Do Advertisers Get What They Pay For?
Conventional advertising wisdom would predict that commercials aired during television programs with strong sexual or violent-action content are more likely to capture the viewers’ attention than commercials aired during blander TV fare.  According to a newly published study in the Journal of Applied Psychology, such conventional wisdom might not be very accurate at all.  The Iowa State University study found that product brand names featured in commercials, when associated with television programs containing strong sexual or violent-action themes, were actually much less likely to be recalled than similar products advertised during more TV mundane fare.  The authors theorize that the provocative content of the featured TV programs competes for the attention and memory of viewers, leaving the advertisement relatively unnoticed and unrecalled.  At the same time, irrespective of this study’s conclusions, some will argue that advertisers are hardly likely to switch their commercials to more boring shows, many of which tend to attract much smaller audiences than their more titillating brethren!

Dr. Robert A. Wascher