I told him I loved it. We will have two sheesha and a pot of mint tea. Very strong. Ahmed touched my arm, furrowed his brow. You have cherry, watermelon, like this. Zaghloul is not for American man. When the waiter returned, he called the pipe a hubbly-bubbly. For some reason, I found this troubling. A small part of me—my intellect—must have known what was coming. It was strong. I took a few deep hits and lay back, extended my legs, enjoyed the sight of abras carrying passengers across the creek.

Larger boats, dhows , were hauling cargo. This was good tobacco. I was mellow, relaxed, happy. When two, three, four, five Ahmeds started looking at me funny. I turned the colour of rotten iceberg lettuce. I began to moan and cradle my head. Ahmed took a long slow puff, exhaled. Well, almost nothing. A traditional majlis will have cushions—usually in a red, white and black striped pattern, from Bedouin culture—on the floor or on a raised platform.

The majlis is often inside a tent. This is the perfect atmosphere for enjoying a sheesha, socializing and tasting local food. Try Arabic coffee from a dallah —an ornate samovar with a long beak, brewed over an open fire. There are hundreds of chic, upscale hookah bars in Dubai.

You can enjoy a smoke from a skyscraper on Sheikh Zayed Road with stunning views of the city, smog and construction dust. Aside from the labour camps, this is the most densely populated part of Dubai.

But what do we know about any long-term consequences? Here, the science is incomplete, as long-term studies of the kind conducted on cigarette tobacco have not been carried out. Researchers admit the evidence is scant, but suggest that smokers of water-pipes could be at long-term risk for nicotine dependence, cardiovascular disease and even cancer.

So bear in mind one thing. Whether you call it shisha, nargile or hubble bubble, it might smell nice, but it is not as harmless as you might think. If you would like to comment on this story or anything else you have seen on Future, head over to our Facebook page or message us on Twitter. Disclaimer All content within this column is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other health care professional.

The BBC is not responsible or liable for any diagnosis made by a user based on the content of this site. The BBC is not liable for the contents of any external internet sites listed, nor does it endorse any commercial product or service mentioned or advised on any of the sites.

Always consult your own GP if you're in any way concerned about your health. Medical Myths Risk. It was smoked after royal dinners and at diplomatic meetings. Offering a hookah to a guest became an important sign of trust and withholding it could be taken as a serious insult. The Hookah tradition spread into the Middle East throughout the 19th century. Hookah integrated into society so deeply in these parts that hookah cafes were built to house the ever-growing popularity.

Hookah promoted a community amongst the patrons, uniting all classes, races, and genders alike. It was used as a way for people to relax, socialize and strengthen bonds with one another. Throughout the 20th Century, hookah traditions continued to deepen in cultures throughout India, Persia, Turkey, the Middle East, and in neighboring countries such as Israel, Armenia, and Pakistan. However, by the late s, hookah has migrated to virtually every continent as immigrants of these countries brought this custom with them to share a piece of their culture to the new world.

In the early 21st Century, a Hookah industry surfaced in the United States as early pioneers found ways to improve the quality of products using modern technology. Even though hookah use in the western world is a recent trend, it has existed for a millennium, emerging in the North Western provinces of India, spreading to Iran, the Arab world, and Turkey and now gaining popularity in the USA and Europe [ 2 ].

PubMed search results for different names of hookah used in the literatures. Hookah is the most common used term followed by waterpipe and shisha. The hookah or hookah apparatus is composed of an upper and lower compartment connected by a pipe Fig.

Briefly, the top consists of a bowl where tobacco or molasses are placed then covered with perforated aluminum foil above which burning charcoal is placed. On the bottom of the apparatus resides a water jar covered by a gasket, protruding a hose and a release valve used for clearing out stagnate smoke [ 1 , 2 , 3 ].

A detailed description of hookah components is provided in Table 1. Indeed, one study reported that differences in pipe material affected the levels of carbon monoxide CO exposure, correlating the non-porous plastic hose with higher yields of CO compared to the more porous leather hose [ 6 ]. The same theory could be applied to yields of other chemicals, especially nicotine. There are three commonly used types of hookah tobacco, Mouassal, Jurak, and Tumbak, each contains different ingredients.

Hadidi and Mohammed [ 8 ] estimated that the nicotine contents of Mouassal is about 3. Jurak is commonly used in the Middle East and Gulf region. Finally, Tumbak, which is used mainly in Asia, is a pure form of unflavored tobacco leaves Ajami smoked with charcoal. In the USA, there are different flavors used in the hookah tobacco with the most popular being the fruit flavors [ 9 ].

Similarly, among university students, fruit flavored tobacco was preferred to unflavored ones [ 10 ]. The user or the person preparing the hookah Fig.

During inhalation, charcoal-heated air passes through the pierced aluminum foil and through the tobacco down the pipe and towards the water. Taken together, hookah smoking seems to have a complex puffing behavior when compared to conventional cigarette smoking. Both cigarette- and hookah-smoking topography serves as an indirect measure of smoke and chemical exposure [ 12 , 14 ]. In comparison to cigarettes, hookah puffing is more variable including total puffing time, number of puffs, and total smoke inhaled, all being affected by the nicotine content of tobacco, the presence of flavors, the personal preferences, and the social setting of the vaping session [ 12 , 15 , 16 ].

Furthermore, number of puffs, mean puff duration, puff volume, and inter-puff intervals were higher in hookah [ 22 , 23 , 24 ], in contrast to conventional smoking [ 25 , 26 ]. Importantly, this higher humidity of the smoke and its cooled down nature facilitates deeper inhalation potentially increasing the side effects of using hookah [ 2 ].

As mentioned before, hookah became widely popular, with its use accelerating rapidly especially among youth and women [ 28 , 29 ]. Although there are ample justifications in the literature for hookah use, in this section, we will include the most commonly reported, in addition to the prevalence of hookah. One factor that drastically contributed to the increased hookah use similarly to e-cigarette use is the misperception about the health risks.

However, nicotine could be easily absorbed through the mucosal lining of oral cavity [ 2 ]. To this end, a recent study conducted on social media Twitter found that social events and flavors were among the common contexts and experiences associated with Twitter discussions about hookah — [ 39 ]. Thus, clearly, there should be more emphasis on research studies that examine hookah health risks, which would inform campaigns for educating the public on the myths and the negative health effects associated with hookah use.

Worldwide, it is estimated that million people use hookah on a daily bases [ 40 ]. Furthermore, while the majority of US hookah users are also tobacco smokers, a significant portion of hookah users are non-smokers [ 35 , 38 ].

In this connection, differences between rural and urban US in smoking hookah were also examined, and the results illustrated more prevalence of hookah use in urban areas in comparison to rural areas [ 46 ]. This difference could be attributed to the sociocultural and economic factors linked to living in urban areas.

It is difficult to determine what might be the cause behind this increase in the west, but potentially, it might derive—in part—from the higher population of Arab Americans within these regions. Regardless, conducting research on hookah environment characteristics such as the number of hookah bars, methods of advertising, and social behaviors could serve as the first step in further understanding the increasing prevalence and popularity of hookah.

Hookah use among US youth population in schools was under scrutiny in many studies. For instance, one study surveyed a representative sample of 6th—12th grade students for hookah use, and the results showed that These results are remarkable as they show that as young as sixth grade vulnerable population can be a user of hookah, and potentially exposed to all associated health risks.

According to the same study, household hookah users and easy access are the main motivation to use hookah in such young age [ 48 ]. Notably, this belief is the major reason many adults use hookah, in addition to viewing it as a good way of socializing, and the belief that it helps quitting cigarettes, as well as being relatively cheaper than smoking cigarettes [ 34 ]. Another drastic and more concerning increase of 5. This is especially troublesome as adolescents continue to be exposed to harmful tobacco product constituents, in particular nicotine that might interfere with brain development, cause addiction, and might lead to sustained future tobacco use [ 53 ].

This increase in use could be attributed to the perception of fewer negative consequences of hookah smoking compared with cigarette smoking and the social norms regarding its acceptability among this population [ 55 , 56 , 57 ]. Regardless of the variability in hookah prevalence among the various populations, clearly, there is an overall drastic increase in its use over a short period. Consequently, it is important to evaluate the major compounds expelled from hookah vape, in order to aid in evaluating both acute and chronic health outcomes.

Several toxicants have been found in mainstream hookah smoke including nicotine [ 27 , 61 , 62 , 63 , 64 ], carbon monoxide [ 27 , 63 ], carcinogenic polycyclic aromatic hydrocarbons PAHs [ 27 , 61 , 63 , 64 , 65 ], aromatic amines [ 63 ], aldehydes [ 64 , 66 ], furanic and phenolic compounds [ 67 , 68 ], tar [ 19 , 61 ], particulate matter [ 69 ], heavy metals [ 19 ], and ammonia [ 70 ].

Comparison of the levels of some toxicant expelled in both hookah and tobacco smoke. Levels of the toxicants a tar, CO, b carbonyl compounds formaldehyde and acetaldehyde , and c certain PAHs are indicated.

Nicotine—the major source of tobacco addiction—content in hookah is extremely variable as it depends on the type of tobacco used. Consequently, the amount uptaken by the user depends on hookah use characteristics that are adjusted depending on nicotine levels in tobacco used in order to deliver desired doses [ 62 ].

Similar to cigarette smoking, plasma nicotine levels were found to be increased in hookah users, indicating systematic delivery of nicotine. This is because CO displaces O 2 from hemoglobin forming carboxyhemoglobin CO affinity for hemoglobin is times that of O 2 and shifting the oxygen dissociation curve to the left, thereby causing hypoxia and impairment of cellular respiration [ 76 ]. Notably, hookah use was linked to several cases of CO poisoning [ 77 , 78 , 79 , 80 , 81 ].

Furthermore, NNAL—a metabolite formed after 4- methylnitrosamino 3-pyridyl butanone NNK enters the body and a well known carcinogen—urinary levels increased markedly after hookah use, indicating the presence of tobacco-specific nitrosamines in hookah smoke [ 63 , 82 ]. Of note, levels of tar delivered vary from session to session, reaching up to folds in some cases of longer hookah smoking sessions [ 84 ].

For instance, aldehydes, such as acrolein, induce cardiopulmonary toxicity [ 85 , 86 ], are potentially carcinogenic [ 87 , 88 ], and are prothrombotic [ 89 ]. Furthermore, the PAHs are carcinogenic [ 90 ], whereas carbon monoxide induces cardiovascular disease [ 91 ], and nicotine is known for its addictive nature [ 92 ].

As for ammonia, which is a strong respiratory irritant, its levels should be measured as part of the assessment of the hookah toxicant profile, and this could be achieved using a simple colorimetric method as was recently described for determining ammonia levels in tobacco fillers and sidestream smoke in different tobacco brands [ 93 ]. Based on the aforementioned considerations, hookah use poses as many or even higher risks for the smoker as cigarette smoking. Ambient concentrations of particulate matter are often used to assess pollution levels from tobacco smoke [ 94 ].

Cigarette smoking expels high levels of particulate matter in bars, exposing both customers and employees passively to hazardous levels of pollutants [ 95 ].

Nonetheless, such low air quality exposes non-users within the household to hazardous materials and puts them under increased risk of disease, especially if they are highly vulnerable with chronic disease, children, and pregnant women.

Consequently, there is a marked need for further research, policies, and better air quality monitoring to improve the indoor air quality in order to reduce passive exposure and its negative health consequences.

Comparison between PM2. While hookah users and those in close proximity are exposed to many of the potentially dangerous toxicants at one time, the health risks associated with its use continue to be under debate.

This is—in part—attributed to the fact that the composition of tobacco smoke in hookah and its puffing patterns are variable and not well standardized. Nonetheless, several studies have provided evidence of health impairments that are associated with hookah use. Theoretically, sharing the mouthpiece during hookah group smoking can be a probable source of transmission of pathogens such as viruses, bacteria, and fungi.

For instance, a study reported a potential risk for transmission of communicable diseases such as hepatitis C when sharing the mouthpiece between users with bleeding gum [ 99 ]. Other studies have also linked hookah to transmission of Helicobacter pylori main cause of peptic ulcer and Aspergillus spores cause of pneumonia in immunocompromised patients [ , ].

Moreover, 48 bacterial isolates were detected from hookah hoses, and among them were virulent as well as antibiotic-resistant strains [ ]. Furthermore, using hookah was linked to developing periodontal diseases in similar magnitude to cigarettes [ ] as well as documented alteration in oral microbial flora [ ].

Similar to cigarette smoking, hookah use is also linked to a harmful impact on the pulmonary system. Thus, hookah users complain of symptoms such as wheezing, cough, sputum, and shortness of breath [ , , ]. FeNO is an essential marker of eosinophilic airway inflammation, and reduction in its levels may be due to rapid conversion of nitric oxide to peroxynitrite by reactive oxygen and nitrogen species or downregulation of nitric oxide synthase [ , ].

Also, hookah users had lower lung diffusing capacity and elevated levels of apoptotic endothelial cell microparticles [ ]. Hookah exposure induced a significant elevation of macrophages, lymphocytes, and neutrophils in broncho-alveolar lavage fluid and altered the levels of several cytokines.

It also increased catalase activity in the lung and resulted in changes in the level and mRNA of major matrix metalloproteinases MMP-1, MMP-9, and MMP , confirming pulmonary damage associated with hookah use [ , ].

To this end, in a population-based study, hookah use was associated with metabolic syndrome development. Thus, hookah users had significantly higher incidence of hypertriglyceridemia and hyperglycemia, as well as hypertension and abdominal obesity, which was observed after controlling for age, sex, social class, and area of residence [ ]. Unfortunately and as stated before, the number of hookah users among the vulnerable populations of pregnant females and adolescents is increasing.

In fact, pregnant females still use hookah during pregnancy, regardless of its reported hazards. Moreover, the risk of delivering low birth babies tripled, in addition to reported neonatal respiratory distress that is linked to hookah use during the first trimester [ , ]. In a rat exposure model, hookah smoke exposure was shown to be associated with low birth weight, increased neonatal death rate, and lower growth rate among offspring [ ].

Additionally, prenatal exposure to hookah smoke in a murine model of asthma in adult mice offspring also induced airway inflammation and adversely affected lung function [ ]. In utero exposure to hookah tobacco smoke in rats resulted in impaired memory and decreased brain-derived neurotrophic factor in hippocampus of adult male offspring rats [ ].

A study of hookah use among 7th—10th grade students indicated that it may impair adolescent brain development, given that it reduces the levels of the brain-derived neutrophic factor BDNF [ ], which is essential for cognition and behavior [ ]. A relatively recent study also reported a reduction in BDNF serum levels in students reflecting a possibility of systematic adverse health alterations in adolescence, coupled with behavioral changes low attention and aggression [ ]. Moreover, hookah tobacco smoke exposure in rats induced short- and long-term spatial memory impairment [ ], which was associated with reduced hippocampal levels of major oxidative stress biomarkers and oxidative capacity enzymes [ , ].

With respect to carcinogenicity of hookah, it was reported that carcinoembryonic antigen CEA levels were higher in hookah smokers, in comparison to non-smokers, yet not as high as in cigarette smokers [ ]. Furthermore, three case-control studies reported a link between the risk of esophageal cancer and hookah use, with the risk increasing with cumulative use, higher frequency, and the duration of use [ , , ].

Additionally, using hookah was linked to an average of six folds higher risk of lung cancer [ , , , ]. Moreover, it was reported that hookah use may increase the risk of gastric cancer by threefold, albeit the mechanism remains unknown [ ].

In addition, hookah smoking was shown to be genotoxic, leading to DNA damage in lymphocytes, where the magnitude of its genotoxicity was higher than that induced by cigarette smoking [ , ]. Exposure to hookah smoking resulted in elevated plasma and saliva levels of toxic metals, namely cadmium, copper, and zinc [ ], which could contribute to its long-term carcinogenicity. It is noteworthy that many of the aforementioned studies had limitations, for example, no control over use of other forms of tobacco and lack adjustments of the cofounding factors in some case studies, as well as limited assessment of gender and age as cofounders.

Nonetheless and taken together, there is sufficient evidence in support of the association of hookah use with negative human health outcomes. Cardiovascular effects and their underlying mechanisms. These data are compiled from what is reported in clinical studies.

The detrimental acute and chronic effects of tobacco smoking on the cardiovascular system are well established [ , , , , , ]. In light of that, it has been shown that hookah smoke effects on the cardiovascular system are comparable to those of conventional cigarettes. It is noteworthy that a recent meta-analysis reported an odds ratio of association between hookah tobacco smoking and heart disease of 1. Acute effects of conventional smoking, such as increased blood pressure, heart rate, and vascular resistance, have been known for decades [ , , , , , ].

As with tobacco smoking, the instantaneous effects of hookah use include higher systolic and mean arterial blood pressure, as well as elevated heart rate HR [ 17 , 23 , , , , , , ].

These effects have been attributed, in part, to the baroreflex mechanism impairment [ ] or to elevated nicotine plasma level. The latter exhibits adrenergic effects that will enhance local and systemic catecholamine release [ 15 , 18 , , , , ]. Supporting the latter notion, mean post-hookah-smoking HR elevation was doubled in participants using nicotine-containing hookah in comparison to nicotine-free hookah smokers [ ].

Another study reported that changes in the cardiovascular central and peripheral components occur immediately after hookah smoking and include increases in HR, blood pressure, and after occlusion vascular resistance, whereas after occlusion blood flow and outflow were decreased [ ]. The cardiovascular changes were shown to be exacerbated among individuals with low habitual physical activity and physical fitness levels [ ]. More recently, it has been reported that adolescents smoking hookah had significantly lower vascular endothelium growth factor VEGF levels [ ], which might adversely affect vascular growth and function in this population.

Acute use of hookah also induced changes in the peripheral vascular system in similar fashion to cigarette smoking, such that it increased vascular resistance and reduced post-occlusion blood flow. In a manner comparable to cigarette smoking, short-term hookah use significantly impaired flow-mediated dilation FMD , which indicates endothelial dysfunction, but hookah was a weaker predictor for high risk profile [ ]. Furthermore, it was reported that short-term hookah use both tobacco-based and tobacco-free products disrupts the autonomic nervous system regulation on the cardiac cycle, thereby causing a reduction in HRvariability, which—in turn—might aggravate the risk of coronary artery disease development [ 18 ].

Moreover, a significant increase in TXB 2 levels, a metabolite of the biologically active TXA 2 , and an index of oxidative injury were reported after a single hookah smoking session [ ]. This increase in TXB 2 levels would suggest an increase in platelet activity [ ].

Importantly, it has been shown that an increase in platelet activity plays a major role in the pathogenesis of acute myocardial infarction MI [ ] and acute stroke [ , , ]. Therefore, it is not surprising to see a link between hookah smoking and acute MI in young adults [ ], and among patient undergoing cardiac catheterization [ ].

However, no data exist yet on the association between hookah smoking and acute stroke [ ]. Interestingly, and contrary to the hypothesis that hookah decreases myocardial blood flow because of the charcoal combustion nanoparticles vasoconstrictor , a study found that hookah use acutely increased myocardial blood flow. In light of the aforementioned evidence, it is clear that even short-term use of hookah disrupts normal cardiovascular function, as repetitive short-term hookah exposure may be the triggering point of causal chain of reactions ultimately leading to the chronic effects.

With regard to the adverse cardiovascular effects associated with longer-term of hookah use, they are comparable to those associated with cigarette smoking. In this connection, a link between chronic use of hookah and coronary artery disease CAD development has been shown, with the frequency and duration of exposure being critical risk factors to CAD.

Additionally, cardiovascular disease development such as ischemic heart disease IHD and heart failure has been associated with heavy hookah smoking [ ]. These outcomes could be explained by the continuous stress placed on the cardiovascular system as result of exposure to high amounts of CO [ ].

Furthermore, death due to IHD was 1. In accordance with the latter data, dose-response relationship between hookah-years and percent stenosis was also established [ ]. Furthermore, risk of MI and stroke death was significantly increased with hookah smoking. Notably and interestingly, a recent cross-sectional study aimed to examine the relationship between chronic hookah smoking and cardiovascular hemodynamics in adolescents found a reduction in both BP and HR of adolescent hookah smokers versus non-smokers, which is in contrast to previously reported results in adults.

Nonetheless, the exact mechanism underlying such outcome is still unclear but warrants investigation [ ]. Together, hookah use has been associated with many cardiovascular effects that influence or contribute to the decline of the overall health status of members of our communities.

Unfortunately, despite studies documenting cardiovascular disease risks associated with hookah, people continue to assume that it is safer than cigarettes, mainly due to being unaware of its negative health effects. Acute and chronic exposures to hookah smoke resulted in significant changes in kidney function biomarkers such as creatinine and blood urea nitrogen, in mice. This was associated with reduction in antioxidant enzymes and biomarkers including superoxide dismutase for acute and chronic hookah smoke exposures, and catalase, glutathione peroxidase, and thiobarbituric acid reactive substances for chronic exposure [ ].

Acute and chronic exposure of mice to hookah corroborates with the clinical findings that suggest cardiovascular dysfunction. Thus, short-term nose-only exposure to mainstream hookah for 5 consecutive days induced a significant decrease in platelet numbers and amplified in vitro platelet aggregation indicating a prothrombotic state [ , ].

Furthermore, cardiac inflammation with an increase in reactive oxygen species ROS was observed, which consequently caused an elevation in heart glutathione GSH; an antioxidant concentrations. This seems to indicate that an initial adaptive response that counterbalances the potentially damaging activity of ROS [ ] is triggered. The increased cardiac vulnerability may explain the increased systolic blood pressure reported after long-term use, which was not seen post-short-term exposure [ , ].

In summary, both clinical and animal studies have provided substantial evidence of a link between cardiovascular disease development and hookah short- and long-term use.