Not all fats are equal. A new study has suggested that unsaturated fats from plant sources are far better for human health than saturated fats from animal sources. This work analyzed the composition of fats in human blood samples; that composition has been linked to the development of chronic disease. The research, which was reported in Nature Medicine, indicated that changes in fats in the blood can be measured accurately, and they can reflect how diet is linked to cardiovascular disease or diabetes risk.
"Our study confirms with even more certainty the health benefits of a diet high in unsaturated plant fats such as the Mediterranean diet and could help provide targeted dietary advice to those who would benefit most from changing their eating habits," noted senior study author Clemens Wittenbecher, research leader at Chalmers University of Technology.
Although the healthiest diet may not be the exact same for every individual, studies have shown that certain diets are better for health than others. Research has indicated that healthy diets tend to have lower levels of added sugars, fats, and so-called ultra-processed foods like soda and chips, as well as adequate levels of vitamins, fruits, vegetables, whole grains, and healthy fats and proteins.
Experts have also recommended that saturated fats should be replaced with unsaturated fat to reduce the risk of heart disease. But these guidelines have not been confirmed for everyone.
This work aimed to clear up some of the confusion by directly assessing fats or lipids in the blood. A tool called lipidomics can reveal all of the fat types in a sample in detail.
The researchers recruited 113 volunteers; one group ate a diet with high levels of animal-based unsaturated fats while another ate high levels of plant-based unsaturated fats. The investigators compiled a multi-lipid score (MLS) for each person's blood lipids. A plant-based unsaturated fat diet and corresponding high MLS values reflected a healthier profile. Lowering the consumption of saturated animal fats can help boost this score, explained first study author Fabian Eichelmann from the German Institute of Human Nutrition Potsdam-Rehbruecke.
The MLS data was also linked to the rate of cardiovascular disease and type 2 diabetes in data from larger studies of more people. These results followed many more people who were healthy at the start of the study, and who were followed for several years. This research confirmed that individuals with healthier blood lipids, and therefore, higher MLS scores have and a significantly lower risk of developing cardiometabolic diseases.
The work has investigated whether people who had low MLS levels benefited from improving their diet by switching to fewer animal-based saturated fats and more plant-based unsaturated fats. The Mediterranean diet, which fulfills those requirements, was used in one trial. Indeed, people who had low MLS scores at first saw them improve when they followed the Mediterranean diet.
"Diet is so complex that it is often difficult to draw conclusive evidence from a single study," acknowledged Wittenbecher. "Our approach of using lipidomics to combine intervention studies with highly controlled diets and prospective cohort studies with long-term health tracking can overcome current limitations in nutrition research."