Health experts are warning about the devastating consequences of chewing an illegal tropical nut with dentists across Australia reporting an alarming spike in oral cancer symptoms associated with the product.

Key points: Chewed widely across South-East Asia and the Pacific, there's a rise in migrants presenting in Australia with dental health issues

Chewed widely across South-East Asia and the Pacific, there's a rise in migrants presenting in Australia with dental health issues An oral medicine specialist says to watch for signs of cancer including ulcers that do not heal, changes in mouth texture, and white patches of soft tissue

An oral medicine specialist says to watch for signs of cancer including ulcers that do not heal, changes in mouth texture, and white patches of soft tissue Friends and family are urged to help betel nut chewers cease its use

The areca nut, commonly known as betel nut or buai, is prohibited under the Australia New Zealand Food Standards Code and considered a schedule 4 poison, according to the Alcohol and Drug Foundation.

WARNING: This story contains a graphic image.

Market vendors in far north Queensland said the intoxicating nut was being traded illegally in growing quantities across the country.

"It's really in great demand all across Australia," said Cairns market stallholder Aore Groves.

Cairns woman Aore Groves says it's unfair to ban betel nut in Australia when tobacco is widely consumed. ( ABC Far North: Marian Faa )

The tropical nut is chewed widely across South-East Asia and the Pacific and often mixed with lime powder (calcium hydroxide) to produce an addictive paste that stains the teeth and mouth a vibrant red.

It can also cause bad breath, tooth wear, gum recession, bleeding gums, and mouth cancer in regular users.

Ms Groves stopped selling betel nut when authorities cracked down on the product in Cairns, but said regulations had resulted in a booming black market for the product.

"[People] now just sell it at home," she said.

The Queensland Police Service said one person had been charged for possessing betel nut in 2019.

Australian Dental Association oral medicine specialist Professor Michael McCullough said the product was readily available in Melbourne where dentists are reporting a large increase in the number of concerning presentations associated with the product.

"What we've noticed over the past five years is a beginning trend in the risk of oral cancer," he said.

Betel nut is often chewed with lime powder, mustard stick, spices, and tobacco in varying combinations known as 'betel quid'. ( Supplied: Australian Dental Association )

"Twenty years ago we were probably seeing only one or two of these changes associated with the use of betel quid and now we're seeing in Melbourne 30 to 40 in the public system."

Across the rest of the country that figure is estimated to be as high as 100.

Professor McCullough said cases were mostly seen in people recently migrated from countries where betel nut is chewed traditionally, including India and Myanmar.

"It could become a big problem in Australia if the habit continues," Professor McCullough said.

Users warned of 'devastating' health impacts

Professor McCullough said betel nut chewers should be on the lookout for signs of oral cancer such as ulcers that do not heal, changes in mouth texture, and white patches of soft tissue that can not be rubbed away with a finger or cloth.

"Removing tumors from people's mouths and faces often can be disfiguring," Professor McCullough said.

Cancerous lesions on the face are directly related to betel nut consumption. ( Supplied: Australian Dental Association )

"If people present with it really late and it's already spread to lymph nodes, it's already actually spread from the mouth, then the prognosis can be not as good and often requires also radiotherapy and chemotherapy."

He said late presentations of oral cancer could lower the five-year survival rate from 85 to 40 per cent.

He said there was likely to be many more undiagnosed cases of oral cancer in migrant populations that find it difficult to access healthcare.

'My teeth have gone really bad'

One of Australia's closest geographical neighbours, Papua New Guinea, has the world's highest rate of mouth cancer due to the prevalence of betel nut chewing.

Internationally acclaimed Papua New Guinean musician George Telek nearly lost his singing ability when he suffered the disease in 2018.

Papua New Guinean woman Mary Scott said she had been chewing betel nut her entire life but was hesitant to visit a dentist when she moved to Cairns in 2000.

"My teeth have gone really bad. They've gone really short," she said.

"I've been to a dentist once or twice since I've been down here, but for me to go to a dentist is a waste of time."

Cairns resident Mary Scott has noticed a decline in her oral health after years of chewing betel nut. ( ABC Far North: Marian Faa )

She said more awareness was needed around the health risks of the product.

But market stallholder Ms Groves said it was unfair to ban betel nut while tobacco, a leading cause of oral cancer in Australia, was legal.

Resources needed to help regular users quit

Professor McCullough said there was far more awareness about the health impacts and addictive properties of nicotine compared to betel nut.

"I don't think there's really the resources that are out there to help [people quit betel nut]," he said.

"Maybe it's not so much medication support they need but society helping, and their friends and family recognising what they're doing to help them cease the use of betel nut."

He urged people who use the product to see a dentist urgently and to stop chewing the product.

"It is very concerning. If [the trend] does continue we think it will compound the rise in cases of oral cancer in Australia," he said.