Research sponsored by a sugar industry trade group manipulated the scientific argument over drawbacks of sugar and blamed dietary fat for heart problems instead, according to a report by American researchers released Monday. Researchers of the latest report examined internal documents from the Sugar Association, formerly known as Sugar Research Foundation (SRF).

The study published in JAMA Internal Medicine reviewed correspondence between the trade group and a Harvard University professor of nutrition who was co-director of the SRF’s first coronary heart disease research program started in 1965. The group’s first project — published in the New England Journal of Medicine in 1967 — was about fat and cholesterol and their dietary causes of coronary heart disease. It also undermined sugar intake as a risk factor for heart issues.

“This historical account of industry efforts demonstrates the importance of having reviews written by people without conflicts of interest and the need for financial disclosure,” the study authors said, in a statement.

Since 1984, the New England Journal of Medicine has made it a point to make study authors disclose all conflicts of interest, according to the new review. And no direct evidence that the sugar industry wrote or changed the review manuscript for the journal is available. Furthermore, evidence that the sugar industry formed its conclusions is circumstantial, the study authors noted.

“This study suggests that the sugar industry sponsored its first CHD [coronary heart disease] research project in 1965 to downplay early warning signs that sucrose consumption was a risk factor in CHD. As of 2016, sugar control policies are being promulgated in international, federal, state and local venues. Yet CHD risk is inconsistently cited as a health consequence of added sugars consumption,” the authors said.

“Because CHD is the leading cause of death globally, the health community should ensure that CHD risk is evaluated in future risk assessments of added sugars. Policymaking committees should consider giving less weight to food industry-funded studies, and include mechanistic and animal studies as well as studies appraising the effect of added sugars on multiple CHD biomarkers and disease development,” the review concludes.

Researchers of the latest data said that there are limitations to their review. According to them, the papers and documents used in the research do not give a wider look into activities of one sugar trade group and the review is based only on one trade group. Moreover, the authors did not examine the role of other organizations, nutrition leaders or food industries.