HealthDay News — Controversial new research challenges the idea that heart health will improve if people cut saturated fat – typically from animal sources – from their diets in favor of vegetable oil. The findings were published online April 12 in The BMJ.

The researchers behind the new review looked back at a study done between 1968 and 1973. It included 9,423 people, average age 52, living at a nursing home or 1 of 6 mental hospitals in Minnesota. The participants were randomly assigned to eat a normal diet or one in which saturated fat was replaced with foods made with corn oil and corn oil margarine (intervention diet). This part of the study lasted between 41 and 56 months, depending on the hospital.

The health of the participants was tracked for about 3 years. The researchers found no benefit in terms of life span for those on the intervention diet; however, they found evidence that lower cholesterol levels translated to a higher risk of death. For every 30 mg/dL reduction in cholesterol, the odds of dying during the study increased by 22%. The authors of the new study pointed out that their findings might not apply to the general public because everyone in their study was living in a mental hospital or nursing home.

“Findings from the Minnesota Coronary Experiment add to growing evidence that incomplete publication has contributed to overestimation of the benefits of replacing saturated fat with vegetable oils rich in linoleic acid,” the authors conclude.

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