May 31st is World No Tobacco Day, and today’s post will examine a study on the effects of cigarette smoking and risks of coronary heart disease and stroke.
Most folks are well aware of the adverse risks of smoking to health. The first Surgeon General’s Advisory Committee on Smoking and Health report was released in January of 1964. The committee had reviewed more than 7,000 articles related to smoking and disease, available in the medical literature at that time. The committee concluded that cigarette smoking was a cause of lung and laryngeal cancer in men, and a likely cause of lung cancer in women.
The percentage of American’s who smoke has dropped from roughly 42% of the population in 1964, to about 14% today. While these statistics are encouraging, tobacco use still accounts for about half a million deaths in the U.S. each year, and about five million death worldwide.
While most people agree on the health risks of cigarettes, what would be the risk of just one cigarette a day? Certainly the risk couldn’t be too high?
A research group from the UK set out to answer this same question. They performed a meta-analysis and systematic review of published studies from 1946 to 2015, eventually including 141 cohort studies. The researchers looked specifically at the risks of smoking on coronary heart disease and stroke.
When their analysis was completed, the results were astounding. For men, the relative risk of smoking a pack a day (20 cigarettes) on coronary heart disease was 2.04, while smoking only one cigarette a day still carried a 1.48 relative risk. So men who smoked only one cigarette a day still had 46% of the excess risk of those who smoked a full pack per day. The data for stroke was not much better, the relative risk for smoking 20 cigarettes daily was 1.64, while smoking only one cigarette a day still carried a 1.25 relative risk, which was 41% of the excess relative risk of those who smoked a pack a day.
The data for women is equally as grim. The relative risk for coronary heart disease in women who smoke a pack per day is 2.84, while one cigarette per day still has a relative risk of 1.57. So even just one cigarette has 31% of the excess risk of a full pack per day.
The data for women smokers relative to stroke are equally poor. For women who smoke a pack per day, the relative risk for stroke is 2.16, while one cigarette per day still yields a 1.31 relative risk. This means that the one cigarette per day female smoker still carries 34% of the excess risk of a full pack per day smoker, for stroke.
The 141 cohort studies included literally millions of subjects, a broad cross-section of the US population, and would seem applicable to the US population in general. It is crystal clear from these results that even one cigarette per day carries substantial risks, in this case increased risk of coronary heart disease and stroke, in both men and women.
“There is no safe dose of a carcinogen.”– Rachel Carson
(Source- BMJ 2018:360:j3984)
This blog is a review of published medical and scientific literature, and should only be used for informational purposes. It does not constitute medical or health advice, nor does it create a physician-patient relationship with anyone. Discuss any health concerns with your personal physician.