By: Ada Seldin, Staff Editor
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Since the first release of the Surgeon General’s Report on smoking 50 years ago, it has become clear that smoking results in premature death and a myriad of diseases, affecting almost every organ system. Public health initiatives to increase awareness, prevent initiation, and promote smoking cessation have been marginally successful. However, the tobacco epidemic continues to claim millions of lives, and more aggressive strategies are necessary to halt its progression. If smoking persists at the present rate among young adults in the U.S, 5.6 million people currently under the age of 18 are projected to die prematurely from smoking-related illnesses. Evidence revealed in the 2014 Surgeon General’s Report expands the ever-growing list of smoking-related health consequences. Smoking affects almost every organ system in the body and leads to some of the deadliest chronic diseases, such as cancer, cardiovascular disease, and COPD. After more than 50 years of research, we are still discovering new ways in which first and second-hand exposure to tobacco smoke adversely impacts one’s health. The humanistic and economic burden of tobacco use is both devastating and avoidable.1
Lung cancer, attributed to smoking, is the cancer with the highest mortality rate in both men and women. However, reducing the risk of developing lung cancer from tobacco consumption is an uphill battle. Researchers compared the data from two prospective studies carried out by the American Cancer Society (Cancer Prevention Study I (1959-1972) and CPS-II (1982-present)) to those from five contemporary studies (2000-2010), and observed an increase in lung cancer cases among smokers, while lung cancer incidence remained unchanged over the years in the non-smoking group. Interestingly, the increase in lung cancer incidence paralleled a decrease in the number of cigarettes consumed per person and the prevalence of smoking. Between Cancer Prevention Study I and the contemporary studies, the relative risk of developing lung cancer in female smokers as compared to nonsmokers increased almost tenfold from 2.7 to 25.7. Similarly, the relative risk in the male population doubled from 12.2 to 25.0 between the first and last studies. The risk of developing COPD from smoking has also risen in the last 50 years, despite the fact that smokers are consuming fewer cigarettes. These seemingly counter-intuitive observations can be explained by a change in the composition of cigarettes over the years. The specific design changes that are responsible are hypothesized to be the ventilated filters and the tobacco-specific nitrosamines. This theory is supported by the simultaneous shift in the type of lung cancers appearing in modern-day smokers. While the incidence of squamous cell carcinoma, once the most frequently diagnosed lung cancer in smokers, has declined to mirror the decrease in the prevalence of smoking, adenocarcinoma of the lung has emerged, which may be attributed to the change in the composition of cigarettes.
Since the last Surgeon General’s Report, it has come to light that smoking precipitates hepatocellular carcinoma, colorectal adenomatous polyps, and colorectal cancer. And although it is inconclusive, evidence suggests that smoking may cause breast cancer. One thing that is clear is that smoking elevates the risk of dying from cancer and other diseases in cancer patients and survivors.1
Second-hand smoke is a major player in cardiovascular disease, another leader in smoking-related casualties. This year’s report estimates that the exposure to second-hand smoke increases the risk for stroke by 20-30%. On a more positive note, however, evidence suggests that the implementation of laws banning indoor smoking and mandating smoke-free environments has a causal relationship with a lower incidence of coronary events among people under the age of 65. An analogous conclusion may be made regarding cerebrovascular events, but further investigation is necessary. In previous reports, smoking was shown to increase the risk of complications associated with diabetes, such as blindness, kidney disease, and amputations. Now, smoking has been identified as a major risk factor for type 2 diabetes mellitus. Current smokers have a 30-40% higher chance of developing diabetes, with the probability increasing in a dose dependent manner with the number of cigarettes smoked.1
Smoking cigarettes alters immune function, activating certain aspects of immunity while suppressing others. Rheumatoid arthritis, an autoimmune disorder, and pulmonary infections such as tuberculosis are linked to smoking. And continuing to smoke while being treated for rheumatoid arthritis lowers the effectiveness of TNF-αinhibitors, a class of therapeutic agents commonly used. Smoking also seems to be detrimental in Crohn’s disease, but actually protective in ulcerative colitis.1
According to recent data explored by the Surgeon General’s report, the reproductive system is just as severely affected as other organ systems. Several congenital malformations, including orofacial clefts, clubfoot, gastroschisis, and atrial septal heart defects, and ectopic pregnancy (implantation of the fetus outside of the uterus) can be attributed to maternal smoking in early pregnancy. Ectopic pregnancy is a fatal complication for both the fetus and the mother, and must be aborted. Nicotine can also contribute to preterm deliveries and stillbirths. Exposure to nicotine during critical periods of fetal and adolescent brain development has been shown to produce lasting effects on the brain. Moreover, a correlation has been found between erectile dysfunction and smoking. 1
Finally, cigarette use is affiliated with age-related macular degeneration (AMD). Although smoking cessation may reduce the risk of AMD, the benefits may not be seen until 20 years after quitting. Still, the most alarming fact is that the relative risk of dying from cigarette smoking has increased over the last 50 years. This may be because smokers suffer from diminished overall health, which manifests itself not only in countless diseases, but also in the decrease in the ability to recooperate from routine health events such as surgeries or pneumonia.1
In an era during which so much attention is given to cost containment, the high healthcare costs associated with cigarette smoking is more than noteworthy. The annual costs stemming from cigarette smoking exceed $289 billion and include a minimum of $130 billion in direct medical costs, as well as over $155 billion in lost productivity due to premature death from both first and second-hand smoke. With so many members of the society interested in promoting smoking cessation, one factor to take into consideration is that there are disparities in tobacco use among racial and ethnic groups as well as educational level and socioeconomic status. Thankfully, tobacco control measures and litigation against tobacco companies have reduced the prevalence of cigarette smoking among adults from 42% in 1965 to 18% in 2012. There are presently more former smokers in the U.S than current smokers. Nonetheless, because rate of regression in the prevalence of smoking has slowed, projections of the near future using today’s models indicate that the prevalence of smoking among adults in 2050 may still be as high as 15%. The plateau effect in the regression of smoking may be related to the changes in tobacco products that are in use, such as cigars and roll-your-own cigarettes using pipe tobacco. The Surgeon General’s review of scientific evidence has thus expanded to include these products.
In order to end the smoking epidemic, “end game” strategies have been proposed, which include reducing the nicotine content to make cigarettes less addictive and creating greater restrictions on sales, even going so far as banning entire categories of tobacco products. Electronic cigarettes, produced by over 250 companies, have gained a foothold in the market, but much remains to be learned about their potential toxicity and health effects. Meanwhile, the U.S Department of Health and Human Services has prepared a framework for coordinating efforts to reduce the rate of smoking in adults and youth to 10% in 10 years. “Ending the Tobacco Epidemic: A Tobacco Control Strategic Action Plan for the U.S Department of Health and Human Services”seeks to counteract the tobacco industry marketing with consistent national anti-smoking media campaigns, raising the average excise cigarette taxes, increasing the FDA regulation of tobacco products, and expanding access to counseling and medications to all smokers under the Affordable Care Act. Smoking is an epidemic. And just as worldwide eradication of smallpox and polio was achieved through focused, goal-oriented efforts, eliminating smoking-related morbidity and mortality should follow the same approach.1
SOURCES:
- The health consequences of smoking —50 years of progress: a report of the surgeon general. U.S. Department of Health and Human Services. CDC website. http://www.cdc.gov/tobacco/data_statistics/sgr/50th-anniversary/index.htm Published 2014. Accessed on Feb. 6, 2014.
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