Nearly 50 years ago, an American sugar industry trade group shut down a study that was producing evidence linking the carbohydrate to disease, according to new research published in the journal PLOS Biology.

The Sugar Research Foundation (SRF) was funding animal studies in order to evaluate sucrose's effects on heart health. However, an examination of internal documents showed that the foundation terminated the project in 1969 before any results were published after evidence emerged suggesting that sugar could be associated with coronary heart disease and bladder cancer.

Researchers Cristin Kearns, Dorie Apollonio and Stanton Glantz, from the University of California at San Francisco, also say that the SRF (which changed its name to the International Sugar Research Foundation in 1968) had secretly funded a review article in 1967 downplaying another animal study that linked sugar consumption to heart disease.

The review argued that gut microbes, not sugar, were responsible for higher cholesterol in rats, and also dismissed the relevance of animal studies to understanding human diseases.

The researchers say that this kind of manipulation on the part of the sugar industry continues to this day. Last year, the Sugar Association criticised a mouse study suggesting a link between sugar and increased tumour growth and metastasis, saying that, "no credible link between ingested sugars and cancer has been established".

However, the latest findings show that the industry was aware of this link half a century ago and halted funding to protect its commercial interests.

"The kind of manipulation of research is similar what the tobacco industry does," Glantz said. "This kind of behaviour calls into question sugar industry-funded studies as a reliable source of information for public policy making."

"Our study contributes to a wider body of literature documenting industry manipulation of science," the researchers write in the paper.