There is growing evidence that hookah smoking affects heart rate and blood pressure, with chronic use linked to an increased risk of heart disease, the American Heart Association warned Friday.
Use of hookah or shisha pipes to smoke tobacco is on the rise among young people in the United States and elsewhere, with the National Youth Tobacco Survey showing 4.1% of American high school students smoked hookah over the previous 30 days in 2011, compared with 4.8% in 2016, according to the American Heart Association. The authors of the new report also warn that there is often a misperception that it is less harmful than cigarette smoking, according to the association.
"Many young people mistakenly believe that smoking tobacco from a hookah is less harmful than cigarette smoking because the tobacco is filtered through water, but there is no scientific evidence that supports that claim," said lead author Aruni Bhatnagar, a professor of medicine at the University of Louisville in Kentucky.
Smoking hookah carries health risks such as diabetes, obesity and increased risks of heart disease and heart attack, he explained.
"From the review of the evidence, we found that hookah smoke contains many of the same toxic chemicals that are present in cigarettes, and sometimes, these harmful chemicals are even higher in hookah than in cigarettes." The report reviewed more than 100 studies on hookah smoking.
Smoking cigarettes and hookah have similar effects on the body, but "what happens with hookah is that you get a lot of exposure in a small amount of time," said Bhatnagar, who is also director of the University of Louisville Diabetes and Obesity Center.
For example, both cigarette and hookah smokers are exposed to the chemical carbon monoxide. But a single session of hookah use, typically 30 minutes long, exposes the smoker to higher levels of the chemical than a single cigarette.
During one hookah session, many liters of smoke filled with large quantities of the pollutant particulate matter are inhaled at higher concentrations than cigarettes, the report says. These particles can be harmful to your health because they irritate the eyes, nose or throat, and smaller particles can get into the lungs and even the blood.
Hookah also contains other potentially harmful chemicals that can affect a smoker's cardiovascular system, such as nicotine or lead. Most of these chemicals are higher in concentration in hookah than in cigarette smoke. This is due to charcoal being burned in hookah and different durations and temperatures.
Long-term use of water pipes has also been linked to an increased risk of coronary artery disease, according to the report. Observational studies from Pakistan and India showed that "people who use hookah on a regular basis have higher levels of risk in terms of developing heart disease," Bhatnagar said.
Originally from ancient Persia and India, hookah, also known as shisha or water pipe smoking, has been around for centuries. However, it's recently become more popular among young adults, the report says.
One survey conducted in seven Middle Eastern countries found that hookah usage by 13- to 15-year-olds was between 9% and 15%, the report said.
A survey of UK students between 2011 and 2012 showed that hookah was more than twice as popular as cigarette smoking for this group. In the United States, people between the ages of 18 and 24 made up over half of hookah users across the nation, according to data from 2013 to 2014 analyzed by the Centers for Disease Control and Prevention and the Food and Drug Administration.
What's behind the rising numbers?
Some of the factors behind hookah's appeal are similar to what attracts young people to Juul or e-cigarettes, namely flavorful tobacco options and social media.
Flavors and sweeteners that can be added to the tobacco make the smoke less harsh and therefore easier to start and continue smoking hookahs, according to the research cited in the study.
Many people consume hookah in lounges or cafes, giving it an image of being less habit-forming, the report added.
One 2009 study, cited in the report, indicated that 58% of hookah smokers believed it to be less harmful than cigarette smoking.
"People believe that occasional use of hookah does not really matter because they would not get addicted," Bhatnagar said. But there is evidence that even occasional use of hookah "could be addictive and could be a catalyst for transitioning into other tobacco products, which is cigarettes," he explained.
"Hookah smoking is still tobacco smoking," said Dr. Mohammed Jawad, a research postgraduate at the Imperial College London. While the report focuses on heart disease, "one of the biggest killers worldwide," Jawad said, other research shows hookah is also linked to several cancers and lung diseases.
"The general public should be made aware of the harms of this hookah smoking through increased regulation and health promotion efforts," said Jawad, who was not involved in the research.