Hookah vs. cigarettes: New research challenges old beliefs.

With hookah use on the rise, particularly among young people, parents and educators may want to take note of new research that suggests that hookah smoke typically contains far more toxins than cigarette smoke. The findings appear to contradict the popularly held belief that passing tobacco smoke through water filters out harmful components. 

A meta-analysis – compiling the results of 17 separate studies on the effects of tobacco use – concluded that smoking tobacco through a hookah, an ancient water pipe frequently used for communal smoking, produces several times more smoke and related toxicants than a single cigarette. (Some hookah users smoke flavored "shisha" which does not necessarily contain tobacco or nicotine. This analysis focused on tobacco use.)

The findings could have wide-ranging policy implications as some states consider raising the minimum age to purchase tobacco products from 18 to 21. Hawaii became the first state to implement a higher smoking age this month, and eight states, as well as the District of Columbia, are considering similar measures. Communities that have adopted local ordinances to that effect have been careful to word legislation to include a wide variety of smoking products beyond cigarettes in response to evidence that many young people begin smoking alternative apparatuses, such as hookah or electronic cigarettes, rather than traditional cigarettes.

The researchers, led by Dr. Brian Primack of the University of Pittsburgh School of Medicine, sifted through 272 unique scientific studies to focus on the 17 that involved laboratory experimentation of single cigarette or water-pipe tobacco smoking (WTS) sessions, within a 95 percent confidence interval.

The meta-analysis estimated the relevant toxicants inhaled, including smoke, nicotine, tar, and carbon monoxide, per cigarette or WTS session. The results showed a higher presence of all four substances in WTS sessions than in a cigarette, including 120 times the volume of smoke, 25 times the amount of tar, more than 10 times the amount of carbon monoxide, and more than two times the amount of nicotine.

“Our results show that hookah tobacco smoking poses real health concerns and that it should be monitored more closely than it is currently," Dr. Primack said in a press release.

While the results point to higher levels of toxicants in hookah smoke, the study notes that the comparison between a single WTS session and a single cigarette is not exact as research does not generally report on a single puff or similar measurement of each consumption method. Smoking habits also differ from person to person and between both types of usage; the study notes that a heavy smoker may consume 15-25 cigarettes per day or 3-6 hookah bowls per day, but hookah bowls typically burn much longer than cigarettes do.

The measurement of tobacco in each puff may vary as well. The typical cigarette, for example, usually contains around one gram of tobacco while hookah bowls differ in size and can hold anywhere from 10 to 20 grams of tobacco. Tobacco in hookah bowls may also be wetter than in cigarettes and is frequently mixed with sweeteners and flavors, making a direct evaluation difficult.

The study concludes that while making conclusive comparisons between the two inhalation methods is not exact, it seems clear that WTS sessions produce a higher amount of toxicants for smokers than single cigarettes. The analysis also comes as the Centers for Disease Control and Prevention reports hookah use by US youth has risen as cigarette use has fallen.

"It's not a perfect comparison because people smoke cigarettes and hookahs in very different ways,” said Primack.

"We had to conduct the analysis this way-comparing a single hookah session to a single cigarette-because that's the way the underlying studies tend to report findings,” he said. “So, the estimates we found cannot tell us exactly what is 'worse.' But what they do suggest is that hookah smokers are exposed to a lot more toxicants than they probably realize.”