REPLACING food rich in saturated fats, such as butter or lard, with those rich in unsaturated fats, such as olive oil, has long been known to reduce low-density lipoprotein (LDL) cholesterol. However, identifying the plant-based oil that is most effective has proven difficult. Now, a study, conducted at the German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany, has revealed seed oils as being of greatest benefit for consumers.
Using databases dating back to 1980, researchers identified 55 studies that met their inclusion criteria for assessing the levels of various lipids in the blood following the equal consumption of two or more types of solid fats or oils over a minimum of 3 weeks; the meta-analysis ultimately included data from 13 different oils and solid fats: safflower oil, sunflower oil, rapeseed oil, flaxseed oil, olive oil, hempseed oil, corn oil, coconut oil, palm oil, soybean oil, butter, beef fat, and lard.
Researchers analysed these studies regarding reductions in LDL levels, finding safflower oil, sunflower oil, rapeseed oil, and flaxseed oil to be the most effective, notably outperforming olive oil, among others. “Some people from Mediterranean countries probably are not so happy with this result, because they would prefer to see olive oil at the top. But this is not the case,” noted Dr Lukas Schwingshackl, German Institute of Human Nutrition Potsdam-Rehbruecke. Perhaps unsurprisingly, solid fats, like butter and lard, were found to be the worst performers.
This analysis focussed on LDL levels, which, despite being a useful risk factor for heart disease, do not represent disease outcomes. “This is not a hard clinical outcome,” explained Dr Schwingshackl, “LDL is a causal risk factor for coronary heart disease, but it’s not coronary heart disease.” Nonetheless, this data adds to the current understanding of the intricate relationship between diet, LDL, and heart disease, and may be used to develop improved nutritional interventions in the future.