The sugar industry funded animal research in the 1960s that looked into the effects of sugar consumption on cardiovascular health — and then buried the data when it suggested that sugar could be harmful, according to newly released historical documents.

The internal industry documents were uncovered by researchers at the University of California, San Francisco, and described in a new report in the journal PLOS Biology on Tuesday. The report’s authors say it builds on evidence that the sugar industry has long tried to mislead the public and protect its economic interests by suppressing worrisome research, a tactic used by the tobacco industry.

The documents show that in 1968 a trade group called the Sugar Research Foundation, known today as the Sugar Association, funded a research project on animals to shed light on the connection between sugar and heart health. But when the research pointed to a mechanism by which sugar might promote not only heart disease but also bladder cancer, the industry group ended the study and never published the results.

The sugar industry has long insisted that sugar has no unique role in promoting obesity, diabetes or heart disease, though numerous studies by independent researchers have concluded otherwise. Stanton Glantz, a professor of medicine at U.C.S.F. and an author of the new report, said that even though the newly discovered documents are 50 years old, they are important because they point to a decades-long strategy to downplay the potential health effects of sugar consumption.