Submitted to: Journal of Agriculture and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/5/2007
Publication Date: 2/13/2008
Citation: Prior, R.L., Wu, X., Gu, L., Hager, T., Hager, A., Howard, L.R. 2008. Whole berries vs. berry anthocyanins: Interactions with dietary fat levels in the C57BL/6J mouse model of obesity. Journal of Agriculture and Food Chemistry. 56(3):647-653.
Interpretive Summary: Obesity is recognized as a major health issue in the U.S. and other developed countries. Diet is one component of a multitude of complex factors that can impact this problem. The recent findings that phytochemicals in fruits (called anthocyanins) could possibly affect the development of obesity in animals has generated considerable interest. Many berries are rich sources of anthocyanins. Rather than studying the effects of purified anthocyanins, as other researchers have done, we studied berry-containing diets fed to mice. After 8 weeks, mice fed high fat diets plus purified anthocyanins from blue berries in the drinking water, had lower body weight gains and body fat. Feeding the whole strawberry powder had some impact on obesity as indicated by the better glycemic control and trends toward decreased body fat and lack of any increased body weight gain. Mice fed a high fat diet containing whole blueberry powder had increased body weight gain and increased adiposity relative to high fat fed controls. However, feeding of the isolated anthocyanins from blueberry and strawberry decreased weight gain and body fat. Anthocyanins fed as the whole blueberry did not prevent and may have actually increased obesity.
Technical Abstract: Male C57BL/6J mice received diets with either 10% of calories from fat (LF) or a high fat diet [45% (HF45) or 60% (HF60) cal. from fat] for 92 days (Expt. 1) or 70 days (Expt. 2). These were given with or without freeze dried powders from whole blueberries (BB) or strawberries (SB) (Expt. 1), or purified anthocyanin extracts from BB or SB (Expt. 2). Body composition was determined utilizing Echo MRI. Berries added to the LF diet did not alter weight gain, final body weights, body fat or protein (% BW), or diet (g) or energy (kcal) intake. However, in both HF45- and HF60-fed mice, weight gain, final weights, body fat (%), and epididymal fat weights increased and body protein decreased (p<0.01) compared to LF mice. In mice fed HF45 diet plus BB, body weight gains, body fat (% of BW), and epididymal fat weights were significantly greater than in the HF45-fed controls, while weights of mice fed SB HF were similar to HF controls. SB or BB feeding did not alter glucose tolerance, although glucose tolerance decreased with age and in HF45 vs. LF mice. Baseline plasma glucose was lower in SB vs. HF45-fed mice. After 8 weeks, mice fed the HF60 diet plus purified anthocyanins from BB in the drinking water, had lower body weight gains and body fat than the HF60-fed controls. Anthocyanins fed as the whole blueberry did not prevent and may have actually increased obesity. However, feeding purified anthocyanins from blueberries or strawberries reduced obesity.