The US sugar industry conspired to push research away from decreasing sugar consumption to ways of mitigating its effects on teeth, researchers say.

The sugar industry convinced US government scientists decades ago to research ways of preventing cavities that did not involve eliminating sweets from the diet, a study has revealed.

The findings in the journal PLOS Medicine on Tuesday were based on 319 industry documents from the 1960s and 1970s that were stored in a public library collection at the University of Illinois.

They show that "a sugar industry trade organisation, representing 30 international members had accepted the fact that sugar caused tooth decay as early as 1950," said the study, authored by experts at the University of California, San Francisco who discovered the archives.

By 1969, the National Institutes of Health had decided that reducing sugar consumption, "while theoretically possible," was not practical as a public health measure, the researchers said.

Representatives of the sugar industry then worked closely with the NIH, the main US government research body, on alternative research approaches.

The study found that 78 per cent of the trade organisation's own research priorities were directly incorporated into the 1971 National Caries (tooth decay) Program's first request for research proposals from scientists.

"The dental community has always known that preventing tooth decay required restricting sugar intake," said first author Cristin Kearns, a UCSF postdoctoral scholar.

"It was disappointing to learn that the policies we are debating today could have been addressed more than forty years ago."

Kearns and colleagues compared the papers - which included 1,551 pages of correspondence among sugar industry executives from 1959 to 1971 -- to documents from the then National Institute of Dental Research, to explore how the sugar industry may have influenced the research policies of the 1971 tooth decay program.

They found that the sugar industry funded research on enzymes to break up dental plaque and a vaccine against tooth decay, and "cultivated relationships with the NIDR and that a sugar industry expert panel overlapped by all but one member with the NIDR panel that influenced the priorities for the NIH tooth decay program".

"These tactics are strikingly similar to what we saw in the tobacco industry in the same era," said co-author Stanton Glantz.

The researchers also found that the sugar industry-led efforts "largely failed to produce results" when it came to preventing cavities, which affect half of US adults and are the leading chronic health problem in American children.

Ronald Burakoff, chairman of dental medicine at North Shore University Hospital in Manhasset, New York, found the study to be "quite disturbing".

The research suggests the sugar industry "conspired to push the research agenda away from decreasing sugar consumption to ways of mitigating the damaging effects of sugar consumption," added Burakoff, who was not involved in the study.

"The parallels to the tobacco industry's denial of the harmful effects of smoking are alarming."

The National Institute of Dental and Craniofacial Research -- the NIDR's successor -- did not immediately respond to an AFP request for comment.