Development of obesity is reduced in high-fat fed mice fed whole raspberries, raspberry juice concentrate, and a combination of the raspberry phytochemicals ellagic acid and raspberry ketone

Abstract

BACKGROUND: A significant body of research demonstrates that intake of berries and berry phytochemicals favorably influence metabolism via a number of different biological mechanisms. However, raspberries and select phytochemicals present in raspberries have been less studied than several other berry fruits. OBJECTIVE: The current study tested the relative effect of whole raspberry products or raspberry phytochemicals using the C57BL/6J mouse fed a high-fat, high-sucrose diet as a model for the obesigenic Western diet. The development of obesity and related metabolic complications were measured. METHODS: C57BL/6J mice were fed experimental diets for ten weeks. Diets were formulated to include a typical dietary level of whole raspberry food products, or for the case of ellagic acid (EA) and raspberry ketone (RK), levels that could be reasonably achieved with typical dietary supplement use. In week nine, a glucose tolerance test was conducted. After ten weeks, animals were sacrificed, serum collected, and liver tissue saved for histology and lipid accumulation measurements. RESULTS: Addition of raspberry food products and phytochemicals to high-fat diet reduced body weight gain significantly when raspberry juice and puree concentrates (RJC and RPC), and the EA+RK combination were added. Food efficiency values reflected these weight changes, with the same three groups having food efficiencies similar to normal-weighted lowfat fed mice. Serum insulin and resistin levels were measured and resistin levels were reduced in the two groups fed high fat diets with RPC or RJC added. A histological evaluation of liver tissue was completed and some differences were impacted by diet. CONCLUSIONS: When added to a high-fat diet, raspberry juice and puree concentrates and the combination of EA+RK decreased weight gain and food efficiency obesity associated with consumption of the obesigenic high-fat, high-calorie diet. Future studies are required to determine mechanisms that may be responsible for these changes.