The use of a commercial vegetable juice as a practical means to increase vegetable intake: a randomized controlled trial
1 Department of Nutrition, University of California Davis, One Shields Ave, Davis, California 95616, USA
2 Department of Nutrition and Exercise Science, Bastyr University, Juanita Drive NE, Kenmore, Washington 98028, USA
3 Global Nutrition Department, Campbell Soup Company, One Campbell Place, Camden, New Jersey 08103, USA
4 Office of Scientific Affairs, Campbell Soup Company, One Campbell Place, Camden, New Jersey 08103, USA
5 Institute for Biobehavioral Health Research, National Development and Research Institutes (NDRI), West 143rd Street, Leawood, Kansas 66224, USA
6 Department of Medicine, Baylor College of Medicine, Travis St, Houston, Texas 77030, USA
7 Division of Rheumatology, Allergy and Clinical Immunology, University of California Davis School of Medicine, Health Sciences Drive, Davis, California 95616, USA
8 Department of Internal Medicine, University of California Davis School of Medicine, V Street, Sacramento, California 95817, USA
Nutrition Journal 2010, 9:38 doi:10.1186/1475-2891-9-38Published: 17 September 2010
Recommendations for daily dietary vegetable intake were increased in the 2005 USDA Dietary Guidelines as consumption of a diet rich in vegetables has been associated with lower risk of certain chronic health disorders including cardiovascular disease. However, vegetable consumption in the United States has declined over the past decade; consequently, the gap between dietary recommendations and vegetable intake is widening. The primary aim of this study is to determine if drinking vegetable juice is a practical way to help meet daily dietary recommendations for vegetable intake consistent with the 2005 Dietary Guidelines and the Dietary Approaches to Stop Hypertension (DASH) diet. The secondary aim is to assess the effect of a vegetable juice on measures of cardiovascular health.
We conducted a 12-week, randomized, controlled, parallel-arm study consisting of 3 groups of free-living, healthy volunteers who participated in study visits at the Ragle Human Nutrition Research Center at the University of California, Davis. All subjects received education on the DASH diet and 0, 8 or 16 fluid ounces of vegetable juice daily. Assessments were completed of daily vegetable servings before and after incorporation of vegetable juice and cardiovascular health parameters including blood pressure.
Without the juice, vegetable intake in all groups was lower than the 2005 Dietary Guidelines and DASH diet recommendations. The consumption of the vegetable juice helped participants reach recommended intake. In general, parameters associated with cardiovascular health did not change over time. However, in the vegetable juice intervention groups, subjects who were pre-hypertensive at the start of the study showed a significant decrease in blood pressure during the 12-week intervention period.
Including 1-2 cups of vegetable juice daily was an effective and acceptable way for healthy adults to close the dietary vegetable gap. Increase in daily vegetable intake was associated with a reduction in blood pressure in subjects who were pre-hypertensive at the start of the trial.