Yoon S. Byun/The Boston Globe via Getty ImagesIf you’ve ever visited Papua New Guinea you’ll have been struck by the friendliness of the people, and their welcoming smiles. You might also have noticed some of those smiles are red.It’s caused by the chewing of “betel quid”, a mixture of unripe areca nut, mustard stick and slaked lime (calcium hydroxide). Chewing betel quid is commonly practised by the Indigenous people of PNG and ingrained in their culture. It is used as way of greeting guests, a meeting snack and even a conversation starter.The primary alkaloid found in areca nut is arecoline which stimulates the release of dopamine and explains the pleasant feeling chewing betel quid delivers. It may also be why betel quid can be addictive.But arecoline is also categorised as probably carcinogenic to humans by the International Agency for Research on Cancer administered by the World Health Organization (WHO). Betel quid’s other ingredients can affect the arecoline concentration, too. A study comparing the betel quid chewed in five regions of Indonesia found the highest concentration was in the mixture chewed by the people of the West Papua. The WHO’s Global Cancer Observatory has estimated Papua New Guinea has the highest incidence rate of oral cancer among 185 countries, closely followed by India, Bangladesh and Pakistan (with tobacco also implicated in these statistics). Combating cultural practiceTo tackle this quiet epidemic, the dentistry division of the School of Medicine and Health Sciences at the University of Papua New Guinea is planning a national research project on the prevalence of oral submucous fibrosis – the chronic disorder associated with increased risk of oral cancer. To date, the country still does not have a national cancer registry and the true burden of oral cancer is unknown. But we do know how widespread the practice of betel quid chewing is.Initially, it was mainly practised in the coastal regions where areca nut is grown. With urbanisation came easier access to the nuts throughout the country. Once the non-coastal regions discovered betel quid chewing and the dopamine effect, it became rampant. Today, in the nation’s capital city of Port Moresby, the constituents of betel quid are sold everywhere. Indeed, it’s hard to miss the street vendors standing at the main road intersections, taking advantage of a pause in the traffic to sell areca nuts (and often cigarettes) to motorists. They may be a hazard, but they are only there because of the demand for their product. There is also no age limit to betel quid chewing in Papua New Guinea, and it’s common to see young children chewing and even helping sell areca nuts. Ingrained in the culture: fesh betel nuts for sale in Bougainville, Papua New Guinea. Eric Lafforgue/Art in All of Us/Corbis via Getty Images Screening and reportingOne important aspect of combating the problem has been to determine why oral cancer patients have been presenting for treatment when their disease is so advanced. We needed to know if there was a referral protocol for oral cancer patients in the provincial hospitals.A survey of dentists in 2024 showed there was a knowledge gap limiting the identification of what are known as “oral potentially malignant disorders” (OPMDs). In collaboration with Australian experts, a program was begun to upskill dentists on oral visual examination and early recognition by identifying changes in the colour or thickness of the inner lining of the mouth. Annual workshops have been held for dentists working in the 22 provinces of Papua New Guinea’s four regions. Attendees should now be able to carry out visual oral examinations to recognise OPMDs. Their provincial dental clinics can now report cases of OPMDs and oral cancer. Spreading the knowledgeUnlike the WHO’s tobacco control initiatives, there is no global policy to control areca nut. More research is needed in Pacific and South East Asian countries on the detrimental effects of areca nut chewing so that global control policies can be developed.Meanwhile, on the ground in Papua New Guinea, the oral cancer screening and early detection project is making progress. Dentists from 12 of the country’s provinces have attended the workshops. Ideally, they will return to their provincial hospitals and clinics and pass on the knowledge and skills they have gained. Their oral health teams are required to conduct rural outreach, so this knowledge should begin to make a difference over time.It is also hoped they can advocate to hospital management for dedicated screening areas to be set up within the dental clinics. If we can succeed in this, it should improve early detection and screening, and increase the reporting of oral potentially malignant disorders and oral cancer in the provinces. Eventually, the quiet epidemic caused by betel quid chewing might recede.The author gratefully acknowledges the following people for their support with this project: Professor Nakapi Tefuarani, Executive Dean, and Dr Mahmood Siddiqi, Head of Dentistry, School of Medicine & Health Sciences, UPNG; Dr Paki Molumi, CEO, Port Moresby General Hospital; Professor Michael McCullough, Melbourne University; Dr Elizabeth Sari and Professor Leonard Crocombe, La Trobe University.Nerida Bun does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.