A recent study of patients with heart failure, published in Science, suggests the heart relies on a higher proportion of fatty acids for fuel compared to other parts of the body, like the legs, and consumes a higher proportion of ketones, or fat stores, during heart failure.
Now, new research in Nature Metabolism finds mice fed a high-fat, low-carbohydrate “ketogenic” diet fared better than mice fed low-fat food in advance of heart failure. A similar effect was achieved with a 24-hour fast, a process that turns fat instead of carbohydrates into fuel. High-fat diets with carbohydrate levels that prevented ketosis provided similar benefits. The researchers explain that as the heart pulls from various energy sources during heart failure, it can’t easily convert glucose or fat into fuel. Components for converting carbohydrates into energy change, while processing fat becomes harder. In this study, higher-fat diets strengthened fatty acid oxidation, making fat an accessible fuel source.
To compare dietary input with cardiac output in the mice, the researchers analyzed heart volume and gene expression for reduced cardiac function, heart enlargement, and tissue scarring, all signs of early heart failure. The mice who received the dietary interventions showed reduced symptoms of heart failure. To draw parallel conclusions, human hearts with and without heart disease were studied for gene expression and for physical characteristics of heart failure. However, additional research is needed to understand how humans would respond to similar dietary modifications to treat or mitigate heart failure symptoms.
The study was partially supported by the National, Heart, Lung, and Blood Institute.