Dietary cranberry, blueberry, and black raspberry affect the development of dyslipidemia and insulin insensitivity associated with metabolic syndrome in high fructose fed rats

Abstract

Effects of feeding cranberry, blueberry, and black raspberry powder on select parameters of metabolic syndrome were investigated in 40 growing male Sprague Dawley rats. The five dietary treatments were: 1) control AIN93G diet, 2) high fructose (65% by weight, HF) diet, and 3–5) HF diet with 5% (dry weight) of cranberry, blueberry, and black raspberry powder. Compared to control animals, HF reduced the body weight, abdominal fat, total liver lipids, and liver triglycerides. Urinary nitrate/nitrite excretion was not altered by diet (p>0.05). There was no difference among treatments in fasting and postprandial plasma glucose, uric acid or cholesterol concentrations, but plasma triglycerides were increased by high fructose feeding in both fed and fasted states. All three berries reduced fasting (p<0.01) but not postprandial plasma triglycerides. High fructose feeding increased fasting plasma insulin that was reduced by the berries. Values for homeostatic model of insulin resistance were increased (p<0.05) by HF diet but were reduced by the berries, while values for beta cell function showed a tendency to be reduced by the berries (p<0.09). HF feeding in a purified diet balanced for all nutrients did not produce a strong response in parameters associated with metabolic syndrome in growing rats, but all three berries were partially effective in ameliorating some of these parameters. Funded by USDA, ARS.