Betel quid consumption is an addictive habit with psychoactive properties, used by an estimated 600 million people worldwide 1234. This practice is widespread in Taiwan, with approximately two million habitual users (10% of population) 5. In 2004, the International Agency for Research on Cancer (IARC) declared chewing of betel quid, by itself, to be a Group 1 carcinogen and the areca nut to be, correspondingly, a Group 1 carcinogen 6. Chewing betel quid independently contributes to the risk of oropharyngeal cancer 789, oral mucosal lesions 10, oral leukoplakia 11, oral submucous fibrosis (OSF) 11, liver cirrhosis 12, hepatocellular carcinoma (HCC) 13, diabetes mellitus 14 and adverse outcomes with use during pregnancy 1516. These pertinent health risks highlight the need for cessation of betel quid chewing. Indeed, betel quid chewing is a recognized public health problem in Taiwan; active strategies are necessary to reduce use.

Several factors influence betel quid chewing, including predisposition associated with ethnicity, demographic and psychosocial factors, its accessibility and public policy. Taiwan aborigines have an extensive history of betel quid use. Their habits are dictated by different social and cultural behaviors in both genders. The life expectancy of Taiwan aborigines is one decade lower than the general population 17 and the mortality rate and prevalence of chronic diseases, such as liver cirrhosis, oral cancer and renal failure, are two-to five-folds higher than rest of the Taiwanese population 18. The estimated prevalence of betel quid chewing in Taiwan aborigines is comparably higher than rest of Taiwanese population (42% for Taiwan aborigines; 6% for Taiwanese population)5. Despite studies to investigate the high prevalence of betel quid chewing in Taiwan aborigines, contributing factors and quit patterns between former and current chewers have not been documented. This report provides the first description of prevalence and patterns of cessation in Taiwan aborigines.

A total of 7326 participants completed our questionnaires from aborigines population of 9124. The response rate was 80.3% (7326/9124). All participants were over 18 years of age (mean 45.3 ± 17.0 years). Factors associated with a betel quid chewing habit are shown in Table 1. The prevalence of betel quid chewers (current and former chewers) was 46.1% of total subjects (3291/7144), with the males (53.2%, 2033/3824) higher than females (37.9%, 1258/3320) p < 0.05. After adjustment for all factors with a logistic regression model, factors most associated with betel chewing were male, obesity, less education, married status, Taiwan aborigines, mixed-Taiwan aborigines, drinking alcohol and smoking cigarettes (p < 0.05). It was noteworthy that the adjusted OR stratified by age showed that older group (>= 45 years) was less likely to have chewing habits.

Table 2 depicts the distribution of demographic characteristics, comparing former chewers to current chewers. The 251 former chewers account for 7.6% in betel quid chewers (251/3291). The quit rate for males is 8.2% (167/2033) and 6.7% (84/1258) for females. In the unadjusted analysis, the crude OR showed those who were older, non-Taiwan aborigines, chewing a smaller amount of quids per day (quids <= 10) and consuming no alcohol to be most likely to quit their chewing habits. Adjusting associations with logistic regression, those older than 45 years and with no alcohol consumption habits had a significantly higher quit rate (p < 0.05). However, the Taiwan aborigines were still less likely to quit chewing habits.

Prevalence of current chewers by ethnicity and gender (Table 3), compared to total subjects was 42.6% (3040/7144) and of current betel quid chewers, males and females were 48.8% and 35.4%, respectively. Ethnicity was classified into five groups: both parents are Taiwan aborigines, only father is Taiwan aborigines, only mother is Taiwan aborigines, non-Taiwan aborigines, and others. The highest prevalence of current male chewers was in those whose mother was Taiwan aborigines (55.7%; 64/115). In females, the highest prevalence was among those whose both parents were Taiwan aborigines (39.3%; 1115/2834). The quit rate of betel quid chewing by ethnicity and sex is summarized in Table 4. Excluding others, the highest quit rate (18.5%) was seen in non-Taiwan aborigines males. In contrast, the lowest quit rate was 3.5% among females whose mother is Taiwan aborigines.

Independent effects of alcohol consumption, cigarette smoking and betel quid chewing on cessation were evaluated by stratifying alcohol and cigarette use across the behavior of betel quid chewing (Table 5). For the nondrinker and nonsmoker who chewed betel quid before, the likelihood of cessation increased 1.76-fold over those who drink and smoke. Likelihood was also significantly increased for betel quid chewers who did not drink, but had smoking habits (OR = 2.19; 95% CI: 1.48 – 3.26). After controlling for other factors, similar cessation patterns were observed in the betel quid chewers who had no drinking habits, but did smoke (aOR = 1.99; 95% CI: 1.32 – 2.99).

Research into betel quid chewing and cessation factors is limited. In this large survey, the sociodemographic factors in betel quid chewing behavior and cessation patterns in Taiwan aborigines were examined. Compared to those who never chewed, betel quid chewers were more likely to be male, obese, of lower education, married, Taiwan aborigines or mixed Taiwan aborigines, a drinker and smoker. On the contrary, subjects who were older were less likely to be betel quid chewers.

This study is more reliable than past studies in determining prevalence and betel chewing association factors in Taiwan aborigines, because a randomized and systematic surveillance-style approach was adopted to recruit participants from their own communities.

There were more betel quid chewers among males than females in this study (aOR = 1.14; 95% CI: 1.01–1.30). This might be explained by the higher prevalence of chewing in Taiwanese males 5. Taiwan aborigines have a higher prevalence of betel quid chewing than Han Chinese 5 and are more likely to be betel quid chewers than non-Taiwan aborigines (aOR = 3.83; 95% CI: 3.01–4.89). In Taiwan, betel quid chewing is widespread; chewers are frequently alcohol drinkers and smokers. After adjusting for other factors, the prevalence of drinking and smoking habits was significantly higher in betel quid chewers than in those who never chewed.

Another important finding is that betel quid chewing is closely associated with obesity. Obesity is a recognized risk factor for chronic diseases, such as diabetes mellitus, cardiovascular diseases, and hypertension. According to previous studies, betel quid chewing can increase body mass index (BMI) or contribute to obesity 212223 by the betel quid constituents (alkaloid, arecoline and arecaidine) as inhibitors of γ-aminobutyric acid (GABA) receptor 424.

The present study is the first estimation of quit rates for betel quid chewing among Taiwan aborigines. Our findings indicate that cessation probability increases with older age group, non-Taiwan aborigines, and those who do not drink. Interestingly, another survey on smoking behavior showed a significantly positive association between smoking cessation and increased age 25. We observed that former chewers comprise 7.6% of total users. Within this, Taiwan aborigines (7.2%) and mixed Taiwan aborigines (7.0%) had a lower quit rate than non-Taiwan aborigines (17.9%, p < 0.05). Apart from the Taiwan aborigines heritage, age group and use of betel quid with alcohol influenced the quit rate. Our study suggested that young Taiwan aborigines or mixed-Taiwan aborigines, who were also alcohol drinkers, found it more difficult to abstain from betel quid chewing. Dr. Wen et al. noted the combined effects of cigarette smoking and betel quid chewing in Han Chinese 26 and suggested that betel quid chewing should not to be considered as an isolated issue. Our results have shown the combined effect of betel quid chewing and alcohol consumption also existed in Taiwan aborigines. Therefore, cessation should be viewed conjointly with alcohol consumption.

Clearly, the highest prevalence of both chewing and of quitting chewing was seen in Taiwan aborigines males whose mother was Taiwan aborigines (Table 3 and Table 4). However, in Taiwan aborigines females, this consistent association was not obvious. We suggest that the likelihood of being a current or former chewer was higher in Taiwan aborigines males whose mother is Taiwan aborigines.

Our multivariate analyses noted that alcohol consumption was an independent factor in cessation (Table 5). For the nondrinkers and nonsmokers who chewed betel quid before, their cessation rate was higher than in those who had drinking and smoking habits. Nondrinkers with cigarette smoking had the highest cessation behavior, compared to those who have drinking and smoking habits, even after adjusting for covariates (OR = 1.99; 95% CI = 1.32–2.99). The cessation discrepancy between betel quid chewers with and without alcohol implies that alcohol not consumption have an additional effect on cessation 5. The main outcome of our study is that efforts to encourage cessation of betel quid chewing will need to include efforts to reduce habitual alcohol consumption. In contrast, reducing cigarette smoking also serves as an important step in reducing betel quid chewing 26.

Taiwan aborigines have a high prevalence of betel quid chewing and a low quit rate. Betel quid chewing independently contributes to the likelihood of obesity. Alcohol usage is strongly related to betel quid chewing. Efforts to reduce betel quid chewing might benefit from a combined approach targeting both these habits.

The author(s) declare that they have no competing interests.

CF and JD carried out the studies, participated in the sequence alignment and drafted the manuscript. PH, SJ and YH participated in the design of the study and performed the statistical analysis. YC led this study, and participated in its design and coordination and helped to complete the manuscript. All of the authors participated in the establishment of the system design, and all read and approved the manuscript.