A small randomized crossover study found no meaningful differences in cholesterol or other short‑term cardiometabolic markers when healthy adults consumed either palmitic‑rich or stearic‑rich interesterified fats for six weeks apiece.
Researchers at King's College London and Maastricht University tested two kinds of interesterified fats—hard fats used to replace trans fats and some animal fats—in everyday foods such as margarines, pastries and spreads. The work, published in the American Journal of Clinical Nutrition, examined blends rich in palmitic acid (from palm oil) or stearic acid (from other plant fats).
Study design
- Forty‑seven healthy adults completed a double‑blind, randomized crossover trial.
- Each participant consumed two six‑week diets featuring muffins and spreads made with one of the fats, supplying about 10% of daily energy.
- Researchers assessed blood lipids, triglycerides, insulin sensitivity, liver fat, inflammatory markers and vascular function.
Findings
- The trial found no meaningful differences between the two fats in blood cholesterol or triglycerides, including the total‑to‑HDL cholesterol ratio, a key cardiovascular risk marker.
- Measures of inflammation, insulin resistance, liver fat and vascular function showed no evidence of harm over the study periods. (The journal abstract notes a small difference in one cytokine, IL‑10, with the palmitic‑rich fat versus the stearic‑rich fat; other outcomes were unchanged.)
What they said
- “Not all food processing is bad for us … this research is timely,” said senior author Professor Sarah Berry of King’s College London.
- Lead author Professor Wendy Hall said the results offer “reassuring evidence” that these industrially processed fats, when eaten in amounts typical of everyday diets, are unlikely to have harmful short‑term effects on cardiovascular risk markers.
Caveats and funding
- The study tested short‑term biomarker changes over six‑week diet periods in healthy adults; longer studies are needed to evaluate chronic effects.
- The research was supported by the Malaysian Palm Oil Board.