NCI Press Office
The health effects of cigar smoking are the focus of one of the eight chapters making up NCI's new monograph titled Cigars: Health Effects and Trends. Additional topics include past and recent trends in cigar smoking, the toxic and carcinogenic compounds found in cigar smoke, the addictive potential of cigar smoking, marketing and advertising of cigars, and the policies regulating taxation, labeling, and sale of cigars.
"This monograph provides clear and invaluable information about the disturbing increase in cigar use and the significant public health consequences for the country," said Richard D. Klausner, M.D., director of the NCI. "The data are clear — the toxic substances and carcinogens in cigar smoke, like cigarettes, are associated with increased risks of several kinds of cancers as well as heart and lung disease. In other words, cigars are not safe alternatives to cigarettes and may be addictive."
He added, "To those individuals who may be thinking about smoking cigars, our advice
is — don't. To those currently smoking cigars, quitting is the only way to eliminate completely the cancer, heart, and lung disease risks."
The smoke released from cigars and cigarettes contain many of the same toxic agents (carbon monoxide, nicotine, hydrogen cyanide, ammonia and volatile aldehydes) and human carcinogens (benzene, vinyl chloride, ethylene oxide, arsenic, cadmium, nitrosamines, and polynuclear aromatic hydrocarbons).
However, the amounts of these substances present in cigar smoke are different than in cigarette smoke. For example, compared to a cigarette, a large cigar emits up to 20 times more ammonia, five to 10 times more cadmium (a cancer-causing metal) and methylethylnitrosamine(a cancer-causing agent), and up to 80 to 90 times as much of the highly carcinogenic tobacco-specific nitrosamines.
These differences are due to several factors: the long aging and fermentation process for cigar tobacco leaves results in higher concentrations of nitrate in cigar tobaccos; the nonporous cigar wrappers make combustion of cigar tobacco less complete than that of cigarette tobacco producing more toxic compounds in the smoke; the larger size of most cigars produces more smoke.
The result is that daily cigar smoking carries significant health risks. Not only can cigar smoking cause many cancers (oral cancers, including throat cancer, and cancer of the larynx, esophagus, and lung) but also chronic obstructive lung disease and coronary heart disease. There is also evidence which strongly suggests that cigar smoking is associated with cancer of the pancreas. Many of these cancers — lung, esophageal, and pancreatic — are associated with extremely low survival rates.
For example, compared to nonsmokers, smoking one to two cigars per day doubles the risk of oral cavity (lip, tongue, mouth, throat) and esophageal cancers, and increases by six times the risk of cancer of the larynx.
Cancer risks increase with the number of cigars smoked per day. Smoking three to four cigars per day increases the risk of oral cancers to 8.5 times the risk for nonsmokers; the risk for esophageal cancer is nearly four times as great as nonsmokers.
There are differences in the patterns of cigar and cigarette use. Most cigarette smokers smoke every day and inhale. In contrast, as many as three-quarters of cigar smokers smoke only occasionally, and some may smoke only a few cigars per year. (The health risks of occasional cigar smokers — less than daily — are not known.) The majority of cigar smokers do not inhale.
In spite of these differences, daily cigar smokers and cigarette smokers have similar levels of risk for oral (including throat), larynx, and esophageal cancers. Even among daily cigar smokers (smoking one or more cigars per day) who do not inhale, the risk of oral cancers is seven times greater than for nonsmokers and the risk for larynx cancer is more than 10 times greater than for nonsmokers.
Inhalation, however, does have a strong effect on disease risk. Compared to nonsmokers, daily cigar smokers who reported inhaling deeply had 27 times the risk of oral cancer, 15 times the risk for esophageal cancer, and 53 times the risk of cancer of the larynx.
Cigar smokers are also at increased risk for heart and lung disease compared to nonsmokers. Regular cigar smokers who reported inhaling slightly have double the risk of chronic obstructive pulmonary (lung) disease and increase their risk of coronary heart disease by 23 percent.
However, compared to cigarette smokers, cigar smokers have lower risks for cancer of the larynx and lung as well as heart and lung disease. Inhalation probably plays a strong role in lowering these risks. But, with regular use and inhalation, the heart and lung disease risks of cigar smoking increase substantially, and for some diseases may approach the risks seen in cigarette smokers. In fact, the lung cancer risk from inhaling moderately when smoking five cigars per day is comparable to that from smoking one pack of cigarettes per day.
Another important focus of the monograph is the composition of secondhand smoke from cigars. Cigar smoke contains most of the same toxins, irritants, and carcinogens found in secondhand smoke from cigarettes, but many of these compounds occur in much higher quantities in cigars (including ammonia, carbon monoxide, respirable suspended particulates, and some of the most potent human carcinogens known, tobacco specific nitrosamines).
Researchers found that the concentrations of carbon monoxide at two cigar social events in San Francisco were higher than the levels found on a busy California freeway. Had these indoor exposures lasted eight hours, they would have exceeded the National Ambient Air Quality Standards for outdoor air established by the Environmental Protection Agency. In a separate study, smoke from a single large cigar burned in a home required five hours to dissipate. While no studies have been conducted to determine the health effects on nonsmokers at cigar social events, a significant body of evidence clearly demonstrates an increased lung cancer risk from secondhand smoke.
Besides the health effects, the monograph addresses the current trends in cigar smoking. Since 1993, cigar sales in the U.S. have increased by about 50 percent. Small cigar consumption has increased modestly, about 13 percent, whereas consumption of large cigars has increased nearly 70 percent.
This marks a reversal in a 20-year decline in cigar smoking from 1973 to 1993. Most of the increase appears to be among teenagers and young adult males who smoke occasionally (less than daily).
Smoking surveys show that the current level of cigar smoking among adolescents exceeds the use of smokeless tobacco. For example, the authors report that a 1996 survey of Massachusetts students in grades six to 12 showed that cigar use (smoked a cigar in the last 30 days) ranged from 3.2 percent in sixth grade to as high as 30 percent in high school. These rates are double the use of smokeless tobacco. The same survey showed that 6 percent to 7 percent of girls in grades nine to 11 reported they had used cigars in the past month. In general, twice as many teenage boys compared to girls are likely to smoke cigars.
The greatest increase in adult cigar smoking is among young and middle-aged (ages 18 to 44) white males with higher than average incomes and education. Adult males are about eight times more likely to smoke than females.
The health consequences of regular cigar use, along with the increased use in teenagers, raises several concerns among public health officials. Addiction studies with cigarettes and spit tobacco clearly show that addiction to nicotine occurs almost exclusively during adolescence and young adulthood when young people begin using these tobacco products. The high rates of adolescent use of cigars may result in higher rates of nicotine dependence in this age group. Recent data suggest that cigar smoking today begins at a much younger age than in the past when it was begun primarily as an adult.
Donald R. Shopland from NCI's Smoking and Tobacco Control Program and the coordinator of the monograph, commented that the health risks posed by cigars have been overlooked because for decades cigar use has been so insignificant compared with cigarette smoking. The increased use since 1993 may be a sign that some people, particularly the young, see cigars as a safer alternative to cigarettes. "The new monograph sets the record straight," said Shopland.
More than 50 scientists and other experts outside the government were involved in the compilation of the monograph, including 30 who participated as peer reviewers. David M. Burns, M.D., professor of medicine at the University of California in San Diego, Calif., was the senior scientific editor for the monograph. The consulting scientific editors were Dietrich Hoffmann, Ph.D., associate director, American Health Foundation, Valhalla, N.Y., and K. Michael Cummings, Ph.D., M.P.H., senior research scientist, Roswell Park Cancer Institute, Buffalo, N.Y. A copy of the monograph is available by calling 1 800-4-CANCER. By May 1, the report will be on NCI's website: http://rex.nci.nih.gov; click on "Public", then "Prevention."
Note to Reporters: Single copies of the monograph, organizations with information about cigar smoking, as well as detailed background information about the report are available by calling the NCI press office. Topics in the background questions and answers include: