|HOLLIS, JAMES - Purdue University|
|HOUCHINS, JEFFREY - Purdue University|
|MATTES, RICHARD - Purdue University|
Submitted to: Journal of the American College of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/20/2009
Publication Date: 2/20/2010
Citation: Hollis, J.H., Houchins, J.B., Blumberg, J., Mattes, R.D. 2010. Effects of concord grape juice on appetite, diet, body weight, lipid profile, and antioxidant status of adults. Journal of the American College of Nutrition. 28(5):574-582.
Interpretive Summary: Daily consumption of 2 to 4 servings of fruit is recommended as part of the Dietary Guidelines for Americans. However, it is not clear whether consuming fruit as juice, which is similarly rich in antioxidant vitamins and polyphenols, provides comparable health benefits. Indeed, potentially countering the reported benefits of these nutrients in fruit juices is the risk that the associated energy (calorie) intake will promote weight gain. Short-term studies demonstrate that energy from beverages leads to weight gain because they possess poor satiating properties compared to their solid equivalents. However, limited evidence suggests that the contribution of Concord grape juice (CGJ) to positive energy balance and weight gain may be attenuated by being more satiating than other liquids or by increasing metabolism, an action associated with some of its constituent polyphenols. Nonetheless, CGJ may still contribute to insulin resistance and its associated metabolic abnormalities because of its high fructose and total sugar content. Because of these apparently competing benefits and concerns, we examined the effects of regular CGJ consumption on body weight, markers of metabolic syndrome, and antioxidant capacity. We provided 2 cups daily of CGJ, a polyphenol-free grape-flavored drink or no beverage to 76 overweight adults and measured their body weight, dietary intake and appetite 4 times over 12 weeks as well as their plasma total antioxidant capacity, lipids, and oral glucose tolerance at the beginning and end of the study. We found the consumption of CGJ did not lead to significant weight gain, but the polyphenols-free grape-flavored drink did. The basis of the different response between these two beverages could not be determined by this study, but we hypothesize it may be due to dietary compensation and effects of CGJ polyphenols on metabolic rate and pathways.
Technical Abstract: Concord grape juice (CGJ) is a rich source of phenolic antioxidants with a range of putative health benefits. However, high beverage energy and fructose intake may lead to weight gain and insulin resistance, respectively. This study assessed the effects of CGJ consumption for 12-wk on appetite, diet, body weight, lipid profile, and antioxidant status. Methods: 76 men and women aged 18-50 y with a body mass index (BMI) of 25.0-29.9 consumed either 480 mL CGJ, 480 mL substitute (polyphenol-free) grape-flavored drink (SGD) or no beverage (NTG) daily for 12 wk. Anthropometric indices were measured biweekly, dietary intake and appetite were assessed four times over the study; and plasma antioxidant capacity (ORAC), lipids, and oral glucose tolerance were assessed at baseline and wk 12. Results: Compared to baseline, the SGD group reported a reduction in fullness (p <0.005) and gained 1.6 kg (p <0.05). No significant changes of body weight or composition were observed with CGJ or control (no beverage added to diet). Mean dietary compensation was 98.8% for SGD and 81.0% for CGJ. Serum glucose and insulin area under the curve (180 min) increased slightly, but significantly with CGJ. Plasma ORAC did not differ across groups suggesting no effect of chronic CGJ ingestion on antioxidant status. Conclusions: Daily consumption of CGJ for 12 wk did not lead to significant weight gain, but SGD did. The basis of this differential response could not be documented, but it is hypothesized to be due to dietary compensation and effects of CGJ polyphenols on thermogenesis and substrate oxidation.