Blood fat profiles confirm the health benefits of replacing butter with high-quality vegetable oils

Switching from a diet high in saturated animal fats to one rich in plant-based unsaturated fats affects blood fat composition, which in turn affects long-term disease risk. A recent study published in Naturopathycarried out by a team of researchers from Chalmers University of Technology, Sweden, the German Institute of Human Nutrition, Germany and several other universities, shows that it is possible to accurately measure diet-related lipid changes in the blood and link them directly to the risk of developing cardiovascular disease and type 2 diabetes.

“Our research further confirms the health benefits of a diet high in unsaturated vegetable fats, such as the Mediterranean diet, and could help provide targeted nutritional advice to those who would most benefit from changing their eating habits,” says Clemens Wittenbecher, research leader at Chalmers University of Technology and senior author of the study.

The World Health Organization (WHO) emphasizes the importance of a healthy diet in preventing chronic diseases and recommends replacing saturated fats with plant-based unsaturated fats to reduce cardiometabolic risk. However, the certainty of these guidelines is moderate due to limitations in existing studies.

This new study addresses these limitations by precisely analyzing fats in the blood, also called lipids, using a method called lipidomics. These highly detailed lipid measurements enabled the researchers to link nutrition and disease in an innovative combination of different research types. This new approach combines nutritional intervention studies (using highly controlled diets) with previously conducted cohort studies with long-term health monitoring.

Dietary trials to monitor how changes in food consumption affect blood fat

Some of this research was conducted as part of a dietary intervention study at the University of Reading, UK, involving 113 participants. For 16 weeks, one group consumed a diet high in saturated animal fats, while the other group followed a diet rich in unsaturated vegetable fats. Blood samples were analyzed using lipidomics to identify specific lipid molecules that reflected the different diets each participant consumed.

“We summarized the effects on blood lipids with a multi-lipid score (MLS). A high MLS indicates a healthy blood fat profile, and a high intake of unsaturated vegetable fat and a low intake of saturated animal fat can help maintain such positive MLS levels “, says Fabian Eichelmann from the German Institute for Human Nutrition Potsdam-Rehbruecke and first author of the study.

These MLS results from the nutritional intervention study were then statistically related to the occurrence of cardiovascular disease and type 2 diabetes in large observational studies that had previously been conducted. These large cohort studies initially followed healthy participants for several years. This analysis of data from both sets of studies found that participants with higher MLS, indicating favorable dietary fat composition, had a substantially reduced risk of developing cardiometabolic disease.

Switching to a healthier diet can have the most pronounced health benefits

Additionally, the study examined whether individuals with low levels of MLS, which indicates a high saturated fat content of the diet, specifically benefited from a healthier diet. The Mediterranean diet focuses on providing more unsaturated vegetable fats and was used in one of the large intervention trials, known as the PREDIMED study. Using this study, the researchers found that diabetes prevention was indeed most pronounced in individuals with low levels of MLS at the start of the study.

“Diet is so complex that it is often difficult to obtain conclusive evidence from a single study. Our approach of using lipidomics to combine intervention studies with highly controlled diets and prospective cohort studies with long-term health monitoring can overcome current limitations in nutrition research overcome,” explains Wittenbecher.