Hooked on shisha? Why hookahs might be more harmful than you think

Shisha, hookah or waterpipes are thought by some to be a safer alternative to smoking cigarettes, but the evidence doesn’t necessarily agree

Waterpipe smoking is on the rise, particularly among teenagers and young adults. And one of the likely reasons for this is the belief that shisha is less harmful than cigarette smoking. But is this the case?

Shisha (also known as hookah, waterpipes, hubble bubble) is the name for pipes containing water at the bottom, and a platform at the top where flavoured tobacco (or non-tobacco herbal mixtures) is covered with foil. Hot charcoal is then placed on top of the foil, and when a user breathes through a hose, a vacuum is created, drawing smoke through the water and into the mouth, where it is inhaled into the lungs. Shisha is a social activity, with one pipe sometimes having a number of hoses, or the hose being passed around.

Some users say they believe the water the smoke passes through acts as a filter, purifying the smoke and therefore making it less dangerous, and less addictive. However, there’s little evidence that this is the case, and new research suggests that waterpipe smoking is associated with a number of the same illnesses as cigarette smoking.

The authors of this research, published in the International Journal of Epidemiology, systematically reviewed studies investigating use of shisha and health outcomes. They identified 50 studies that fit these criteria, and found evidence that use of waterpipes was associated with respiratory disease, lung cancer, oral cancer, poor mental health, low birthweight of offspring, metabolic syndrome, and cardiovascular disease.

Of course, these are observational studies, and as such causation can be hard to ascertain. Not only that, but the studies included in this systematic review vary in quality, meaning that combining their results in a meta-analysis isn’t always possible, and even where it is, isn’t necessarily reliable. Perhaps an even bigger problem is that the measure of waterpipe use itself varied dramatically between each study. Some studies only looked at ever versus never using a waterpipe, while others tried to assess cumulative use.

Cigarettes and shisha are used in very different ways, and no studies have directly compared the health risks from cigarette smoking to waterpipe use, meaning a direct comparison of harms is difficult. Shisha may represent lower harm because it is more commonly used socially and at special events rather than smoked every day, or it could represent a more severe problem as the cooler smoke is more pleasurable to inhale so held in the lungs for longer, causing more damage.

There has been far less investigation of the constituents of shisha smoke compared to cigarette smoke, but the research that is available suggests tar, nicotine, carbon monoxide and a number of carcinogens seen in cigarette smoke are also present in shisha smoke. While it might be thought that herbal shisha is safer than tobacco shisha, the burning of the charcoal used to heat the pipe produces carbon monoxide and benzene, which are also inhaled through the pipe. There have been case reports of acute CO poisoning after shisha use, which isn’t the case with cigarettes.

Perhaps even more worryingly, anecdotally there seems to be a lack of understanding that the flavoured products used in waterpipes predominantly contain tobacco. Although there are some herbal products, which claim to be a safer alternative, most of the products available for use, even the flavoured ones, are flavoured tobacco. And while herbal products don’t contain nicotine, they still release a number of the same toxins as found in tobacco smoke, and the CO and benzene from the charcoal is still inhaled.

While the evidence for its impact on health is much sparser for waterpipes than for cigarettes, and some of the individual papers are of lower quality, the information to date suggests that waterpipe use, puff for puff, is likely to be comparable to cigarette smoking. But, although a waterpipe session might last for an hour and involve a great deal more puffs than an individual cigarette, waterpipes are less likely to be used every day so escalation of use, and therefore nicotine dependence, is hopefully less likely. What we really need is more information on how easy waterpipe users find it to quit, and better measures of how waterpipe use changes over time, particularly in these young people who seem to be taking up the habit.