Abstract MP063: The Effects of Lifestyle Interventions on Fruit and Vegetable Intake Assessed by Serum Carotenoids and Self-Report: Results from the PREMIER Trial
Background Trials that attempt to increase fruit and vegetable (F/V) intake commonly rely on self-reported dietary intake data that are prone to bias. Our primary objective was to assess the magnitude of the effect of a dietary intervention on F/V consumption, using two different measures: serum carotenoids and 24-hour dietary recall. A secondary goal was to explore the use of serum carotenoid levels as an indicator of F/V consumption.
Methods Three intervention groups in the PREMIER trial (n=554) consisted of an Advice Only control group, an Established group that received counseling on weight loss, physical activity and sodium reduction (but no advice on F/V intake), and an Established +DASH group that also received counseling on the DASH diet (with advice to increase F/V intake). Self-reported F/V consumption was measured via two 24-hour dietary recalls administered at baseline, 6- and 18-months. Serum carotenoids were collected via fasting blood samples at each time point. Linear mixed models were used to examine the relationship between intervention assignment and F/V consumption. Pearson correlation and ROC curves informed the secondary objective.
Results Compared to the control group, F/V consumption was highest in the Established+DASH group measured by recall (2.95 servings greater, 95% CI 2.43 to 3.47) and serum carotenoids (20.51 ug/dl greater, 95% CI 12.72 to 28.29). However, only 34% (57/167) of the Established+DASH group met the recommended level of 9 servings of F/V per day at 6 months. F/V intake and serum carotenoid levels were similarly and modestly correlated across each time point, ranging from .34 to .42. ROC curves indicated poor or fair performance of carotenoids as indicators of adequate F/V consumption. The area under the curve (AUC) was .692 for 5 servings of F/V, and .697 for 9 servings.
Conclusions The PREMIER dietary intervention was successful in increasing F/V consumption as measured by serum carotenoids or self-report, but only a minority of study participants achieved recommended levels.
|Advice Only (n1=186)||Established (n=185)||Established +DASH (n=183)||p-value2|
|24-Hour Recall (servings/day: mean, SD)|
|18 months||4.6 (2.7)||4.8 (2.5)||7.5 (3.5)||<.001|
|Total Carotenoid Levels3 (ug/dl: mean, SD)|
|18 months||61.1 (37.0)||63.8 (38.3)||79.8 (49.2)||<.001|
|Total Carotenoid Levels+Lycopene, (ug/dl: mean, SD)|
|18 months||85.4 (41.3)||85.3 (40.1)||102.3 (51.4)||<.001|
- © 2012 by American Heart Association, Inc.