KEY POINTS:
Researchers analysing skeletons from a 3000-year-old cemetery in Vanuatu say they show "tantalising clues" that high rates of gout among modern Maori men stem partly from genes carried across the Pacific by ancient voyagers.
Biological anthropologist Dr Hallie Buckley, at Otago University's Department of Anatomy and Structural Biology has been working on bones from the earliest ancient cemetery yet found in the Pacific Islands - between 3200 and 3000 years old - discovered in late 2003 at Teouma, on Efate Island in Vanuatu.
Her paper on the gout damage has just been published in Current Anthropology.
"We examined the bones of 20 skeletons from the first two field seasons using radiography and other techniques and found erosive lesions or damage to the joints of seven of them," Dr Buckley said.
"The pattern of these lesions suggests they were most likely the result of gouty arthritis.
"This surprising finding suggests a very early antiquity of gout in the Pacific Islands."
One third of the skeletons showed damage from gout - a build-up of uric acid crystals in bone joints - and might help explain the unusually high incidence of gout and high uric acid levels in many modern Pacific Island populations, including New Zealand Maori.
The skeletons are from a cemetery of "Lapita people" - named for their distinctive decorated pottery found across the Pacific - who settled in Vanuatu, New Caledonia, Fiji, Tonga and Samoa.
Medical researchers have theorised that the high prevalence of gout in some Polynesian populations may be due to a genetic predisposition.
A genetic marker for gout susceptibility has been identified in Taiwanese Aborigines.
Some researchers have suggested that as their descendants migrated east across the Pacific in voyaging canoes the genes involved had a "founder effect" with a small number of people passing on the trait to a huge number of descendants.
Dr Buckley said the Lapita people's diet of local plants and seafood would have meant seafood rich in compounds called purines could have set off attacks of gout or high levels of uric acid in susceptible people.
"This sort of diet may have favoured the continued selection of high frequencies of ... gout in these ancient explorers."
She said the work would help understand the impact on individuals of coping with potentially debilitating diseases in the ancient community.
"The pain associated with acute gout attacks has been described as excruciating, with an intensity that rivals that of childbirth and long bone fracture"
It was possible sufferers were disabled during acute attacks.
Dr Buckley said the 35 per cent level of incidence - seven of the 20 adult skeletons so far investigated from 50 burials - was "extraordinarily high" compared with the modern frequency of gout in the Pacific Islands.
It might change as more skeletons were dug up.
Other researchers have said half the Polynesian populations of New Zealand, Rarotonga, and Puka Puka in the Cook Islands, and the Tokelaus have blood levels of uric acid high by European standards, with the associated gout rate reaching 10.2 per cent in Maori males aged 20 and over.
WHAT IS GOUT?
* Painful form of arthritis.
* Occurs when too much uric acid builds up in the body.
* Can cause pain, swelling and stiffness in joints.
* Mainly affects the big toe, but can affect the ankles, heels, knees, hands and elbows.
- NZPA
