Improved Diet Quality and Increased Nutrient Intakes Associated with Grape Product Consumption by U.S. Children and Adults: National Health and Nutrition Examination Survey 2003 to 2008
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Fruit contributes to dietary nutrient density and consumption of fruit in several forms (whole, dried, or 100% juice) has been reported to be associated with a healthier dietary pattern. The goal of this study was to examine the associations of the consumption of grapes (including fresh grapes, raisins, and 100% grape juice) with diet quality and food group/nutrient intake. A secondary analysis of Natl. Health and Nutrition Examination Survey (NHANES) 2003 to 2008 data was conducted to compare grape consumers (GC) with nongrape consumers (NGC) among children aged 2 to 19 y (n = 9622) and adults 20+ y (n = 12251). GC were defined as those who mentioned the consumption of fresh grapes, raisins, or 100% grape juice during 1 or both 24-h recall interviews. Compared to NGC, GC had higher Healthy Eating Index 2005 (HEI-2005) scores and higher intakes of total and whole fruit along with lower intakes of solid fat, added sugars, and calories from solid fats, alcohol, and added sugars (SoFAAS). Among adults, GC also had higher intakes than NGC of total and dark green/orange vegetables. Among both age groups, GC had higher intake than NGC of several key nutrients including dietary fiber, vitamin A, vitamin C, calcium, magnesium, and potassium. Consumption of grape products is associated with a healthier dietary pattern and higher intake of key nutrients by both children and adults.
Among children and adults, consumers of common grape products (fresh grapes, raisins, and 100% grape juice) had healthier dietary patterns and higher intakes of key nutrients. Grape products can make a significant contribution to a healthy diet.
The 2010 Dietary Guidelines for Americans (DGA 2010) include a recommendation to increase vegetable and fruit intake (United States Dept. of Agriculture [USDA] and Health and Human Services; [HHS] 2010). The new visual interpretation of the DGA 2010, choosemyplate.gov, recommends that half of the food on a meal plate should be fruit and vegetables (ChooseMyPlate 2011). The Centers for Disease Control and Prevention (CDC) State Indicator Report on Fruit and Vegetables, 2009 (Nutrition for Everyone 2012) reports that fruit and vegetable intake is below recommended levels for both children and adults in the United States despite public health efforts to increase intake. Fruit and vegetables contribute to dietary nutrient density, and increased intake is associated with reduced risk of several chronic diseases (Pelucch and others 2009; USDA and HHS 2010; Aune and others 2011; Bhupathiraju and Tucker 2011; Wang and others 2012). Consumption of 100% fruit juice, grapes, and dried fruit has been associated with improved diet quality in both children and adults based on analyses of Natl. Health and Nutrition Examination Survey (NHANES) data (O'Neil and others 2011a, 2011b; Keast and others 2011; McGill and others 2011). Among children and adults, grape juice consumers have been reported to have improved diet quality with higher intakes of total fruit, vitamin C, and potassium and lower intakes of added sugar, saturated fat, and sodium compared to nonconsumers of grape juice (McGill and others 2011).
Grapes are part of the berry family and have been used for over 2000 years as an edible sweet fruit (Yadav and others 2009). A three-fourth cup serving (126 g or 4.5 ounces) of grapes (red, green, or black) provides 90 calories, 23 g total carbohydrates, 1 g dietary fiber, and 20 g sugar (Code of Federal Regulations Title 21 2012). Vitamins and minerals include 2% Daily Value (DV) each of calcium, magnesium, and vitamin C, 7% DV potassium, and 25% DV vitamin K (Code of Federal Regulations Title 21 2012; USDA Natl. Nutrient Database for Standard Reference 2012 Release 24). Raisins are dried grapes and a one-fourth cup (40 g) serving provides 120 calories, 1 g protein, 32 g total carbohydrate, 2 g dietary fiber, 24 g sugar, 2% DV of calcium and vitamin C, 4% DV of magnesium and iron, and 9% DV potassium (USDA Natl. Nutrient Database for Standard Reference 2012 Release 24). Eight fluid ounces (240 mL) of 100% grape juice contains 150 calories, 1 g protein, 37 g total carbohydrate, 36 g sugar, 2% DV calcium, 6% DV magnesium, 8% DV potassium, and 100% DV vitamin C. All of these grape products are fat- and cholesterol-free and very low in sodium (USDA Natl. Nutrient Database for Standard Reference 2012 Release 24). Grapes, raisins, and grape juice also contain a wide variety of polyphenols, present in the skin, flesh, juice, and seeds, which may have beneficial effects on health (Leifert and Abeywardena 2008; Vislocky and Fernandez 2010, Williamson and Carughi 2010). The biomedical effects of grape products have recently been reviewed and include modulating endothelial function, delaying low-density lipoprotein (LDL) oxidation, lowering blood pressure, and reducing oxidative stress along with beneficial effects on immune markers and cognition (Leifert and Abeywardena 2008; Vislocky and Fernandez 2010; Williamson and Carughi 2010).
Epidemiological studies examining the contribution of grape products as a group (fresh grapes, raisins, and 100% grape juice) to diet quality are limited. The purpose of this study was to examine the relationship between consumption of grapes, in the nonalcoholic forms most commonly consumed (fresh grapes, raisins, and 100% grape juice) and diet quality or nutrient intakes in a recent, nationally representative sample of U.S. children and adults.
Materials and Methods
The continuous NHANES is a cross-sectional survey that collects data pertaining to the nutrition and health status of the U.S. population using a complex, multistage probability sampling design. Data are released in 2-y increments and for this secondary analysis the data sets from 2003 to 2004, 2005 to 2006, and 2007 to 2008 were combined. In the combined NHANES 2003 to 2008, after excluding pregnant and/or lactating females, there were 21873 participants aged 2 y and older whose dietary interviews on both the 1st and 2nd d were considered complete and reliable by the USDA Food Surveys Research Group interviewers who collected the NHANES 24-h recall data. Participants were divided into 2 age groups: children and adolescents 2 to 19 y of age (n = 9622) and adults 20 y and older (n = 12251). The grape category included fresh grapes, raisins, and 100% grape juice. Grape consumers (GC) were defined as those who mentioned any of the items in the grape category during 1 or both 24-h recall dietary interviews that were used to assess dietary intake. Although two 24-h recalls were used to identify GC, only data from the in-person interview (1st recall) were used assess mean HEI-2005 scores and mean nutrient intakes. This secondary analysis of publicly available data was exempt from review board approval.
Nutrient and mypyramid food group analysis
The USDA Food Surveys Research Group determined nutrient intake from foods reported in the NHANES 2003 to 2004, 2005 to 2006, and 2007 to 2008 data sets using their Food and Nutrient Database for Dietary Studies, versions 2.0, 3.0, and 4.0, respectively. MyPyramid food group intake from foods reported in NHANES 2003 to 2004 were determined using the MyPyramid Equivalent Database, version 2.0 (MPED 2.0) (Food Surveys Research Group 2012). Because a more recent MPED was not available, we extended the application of the MPED 2.0 to those foods that were unique to the NHANES 2005 to 2006 and 2007 to 2008 data sets by manually matching them with the most similar NHANES 2003 to 2004 foods that were found in the database. The Healthy Eating Index (HEI-2005) is a validated instrument developed by the USDA Center for Nutrient Policy and Promotion to assess the compliance of the U.S. diet with the recommendations of the 2005 Dietary Guidelines Advisory Committee based on each individual's intake of MyPyramid food groups and nutrients to limit such as saturated fat and sodium, and the HEI-2005 score was calculated using available software (Guenther and others 2007).
Sample-weighted data were used in all statistical analyses, and all analyses were performed using SUDAAN Release 10.0.1 (Research Triangle Inst., Research Triangle Park, N.C., U.S.A.) to adjust the variance for the clustered sample design. Least square means and standard errors of the mean were calculated. An analysis of variance was conducted to discern differences in the mean level of these parameters, after adjusting for potential confounders. The covariates used in analyses of food groups and nutrients were energy, gender, race ethnicity, and age. Gender, race ethnicity, and age were covariates in analysis of energy (kilocalories). Statistical significance was set at P < 0.01 and P < 0.05 levels.
Results and Discussion
Healthy Eating Index (HEI-2005) scores and intake of food group servings by GC and nongrape consumers (NGC) among children and adults are presented in Table 1. Compared to NGC, children and adult GC had significantly higher HEI-2005 scores and higher intakes of total fruit and whole fruit. Among both age groups, GC also had significantly lower intakes than NGC of added sugars, solid fat, and calories from solid fats, alcohol, and added sugars (SoFAAS). Compared to NGC, among children, GC had a lower intake of total grains but there was no between-group difference in whole grain intake. Among adults, GC had higher intakes of total vegetables, dark green/orange vegetables, whole grains, nuts, and seeds compared to NGC.
Table 1. Healthy Eating Index (HEI) and adjusteda meanb food group servings by consumption of fresh grapes, raisins, or 100% grape juice at least once in 2 dc
|HEI-2005||54.6 ± 0.7**||49.4 ± 0.3||57.5 ± 0.5**||51.2 ± 0.3|
|Total fruit (cup)||1.64 ± 0.05**||0.99 ± 0.03||1.64 ± 0.06**||0.89 ± 0.03|
|Whole fruit (cup)||0.94 ± 0.06**||0.48 ± 0.02||1.05 ± 0.04**||0.56 ± 0.02|
|Total vegetables (cup)||1.00 ± 0.04||1.06 ± 0.02||1.79 ± 0.05**||1.60 ± 0.02|
|Dark green/orange vegetables (cup)||0.10 ± 0.01||0.09 ± 0.01||0.25 ± 0.02**||0.17 ± 0.01|
|Total grains (oz)||6.59 ± 0.11*||6.86 ± 0.07||6.68 ± 0.10||6.73 ± 0.05|
|Whole grains (oz)||0.54 ± 0.04||0.48 ± 0.02||0.87 ± 0.05**||0.66 ± 0.02|
|Milk group (cup)||2.26 ± 0.06||2.17 ± 0.03||1.59 ± 0.04||1.57 ± 0.03|
|Meat group (oz)||4.34 ± 0.12||4.14 ± 0.06||6.04 ± 0.15||6.08 ± 0.07|
|Nuts and seeds (oz)||0.36 ± 0.04||0.41 ± 0.03||0.86 ± 0.09*||0.61 ± 0.03|
|Solid fat (g)||45.5 ± 0.6*||47.1 ± 0.4||42.7 ± 0.5**||46.8 ± 0.3|
|Added sugars (tsp)||18.3 ± 0.5**||21.6 ± 0.3||16.8 ± 0.4**||18.9 ± 0.4|
|SoFAAS (kcal)d||709 ± 12**||775 ± 4||738 ± 10**||822 ± 6|
Table 2 presents food energy and nutrient intakes by GC and NGC. Among both age groups, GC had significantly higher intakes of dietary fiber, vitamin A, vitamin C, vitamin B6, calcium, magnesium, and potassium compared to NGC. Among children, GC also had significantly higher intakes of riboflavin and phosphorus than NGC. Adult GC had significantly lower intakes of total fat, saturated fat, and cholesterol than NGC. Adult GC also had significantly higher intakes of total carbohydrate, vitamin E, thiamin, folate, and iron compared to NGC.
Table 2. Adjusteda meanb nutrient intake by consumption of fresh grapes, raisins, or 100% grape juice at least once in 2 dc
|Food energy (kcal)d||2067 ± 28||2026 ± 14||2196 ± 31||2161 ± 15|
|Protein (g)||72.2 ± 0.9||70.6 ± 0.4||83.0 ± 0.8||83.0 ± 0.4|
|Total fat (g)||74.3 ± 0.6||75.7 ± 0.4||79.5 ± 1.0**||83.0 ± 0.4|
|Saturated fat (g)||26.2 ± 0.3||26.6 ± 0.2||26.0 ± 0.4**||27.6 ± 0.1|
|Cholesterol (mg)||231 ± 9||225 ± 3||276 ± 8*||293 ± 3|
|Carbohydrate (g)||274 ± 2||272 ± 1||272 ± 3**||259 ± 1|
|Dietary fiber (g)||13.9 ± 0.3**||12.8 ± 0.1||17.8 ± 0.3**||15.4 ± 0.2|
|Vitamin A (μg RAE)||621 ± 17**||571 ± 9||670 ± 14**||605 ± 10|
|Vitamin E (mg AT)||5.8 ± 0.1||6.0 ± 0.1||8.1 ± 0.2**||7.3 ± 0.1|
|Vitamin C (mg)||100.2 ± 3.0**||82.7 ± 1.6||116.4 ± 4.1**||81.0 ± 1.6|
|Thiamin (mg)||1.62 ± 0.03||1.57 ± 0.01||1.77 ± 0.03**||1.64 ± 0.02|
|Riboflavin (mg)||2.22 ± 0.04*||2.12 ± 0.02||2.28 ± 0.03||2.24 ± 0.01|
|Niacin (mg)||21.5 ± 0.4||21.3 ± 0.2||25.5 ± 0.4||25.0 ± 0.2|
|Vitamin B6 (mg)||1.81 ± 0.04*||1.71 ± 0.02||2.09 ± 0.03**||1.94 ± 0.02|
|Total folate (μg)||391 ± 8*||379 ± 3||431 ± 8**||399 ± 4|
|Vitamin B12 (μg)||5.3 ± 0.1||5.1 ± 0.1||5.3 ± 0.2||5.3 ± 0.1|
|Calcium (mg)||1053 ± 19**||996 ± 10||954 ± 13**||911 ± 10|
|Phosphorus (mg)||1284 ± 16**||1244 ± 7||1355 ± 11||1333 ± 7|
|Magnesium (mg)||241 ± 3**||228 ± 2||315 ± 3**||289 ± 3|
|Iron (mg)||14.9 ± 0.2||14.7 ± 0.1||16.5 ± 0.2**||15.5 ± 0.1|
|Zinc (mg)||11.0 ± 0.2||10.9 ± 0.1||12.1 ± 0.1||12.3 ± 0.1|
|Sodium (mg)||3072 ± 38||3144 ± 3||3421 ± 42||3476 ± 15|
|Potassium (mg)||2414 ± 32**||2189 ± 18||2931 ± 29**||2664 ± 17|
This analysis of NHANES 2003 to 2008 data examined diet quality and nutrient intake differences between consumers and nonconsumers of fresh grapes, raisins, and 100% grape juice. Compared to NGC, children and adults who consumed grapes or grape products had healthier dietary patterns and higher intakes of several key nutrients.
The HEI-2005 is a measure of diet quality that assesses conformance to government dietary guidance (Healthy Eating Index 2006; Guenther and others 2007). HEI-2005 component scores are higher if intakes of total and whole fruit, vegetables and legumes, total and whole grains, milk, meat, and beans are higher, and intakes of saturated fat, sodium, and SoFAAS are lower. Among children and adults, GC had higher HEI-2005 scores than NGC. Among both age groups, GC also had higher intakes than NGC of total and whole fruit and lower intakes of solid fat, added sugars, and SoFAAS calories. Among adults, GC also had higher intakes than NGC of total and dark green/orange vegetables. The dietary pattern reported by GC in this study is similar to the pattern recommended by the 2010 DGA which includes increased intakes of fruit and vegetables, especially dark green and orange vegetables, and reduced intakes of sodium, fat, added sugars, and calories from solid fats and added sugars (USDA and HHS 2010). Fruit product intake has previously been associated with healthier dietary patterns. Significantly higher HEI-2005 scores have been associated with 100% orange juice consumption by children (O'Neil and others 2011b) and dried fruit consumption by adults (Keast and others 2011). Keast and others (2011) also reported that the consumption of raisins and other dried fruit was associated with higher intakes of total fruit, whole fruit, dark green/orange vegetables, total grains, and whole grains. Consumption of the purple/blue color group of fruit and vegetables, including 100% grape juice, has been associated with higher intake of total fruit and decreased intake of added sugar (McGill and others 2011).
In this study, food energy (kilocalories) intake by GC and NGC was not significantly different among children and adults. Among adults, GC had lower intakes of total fat, saturated fat, and cholesterol than NGC. Lower intakes of total fat, saturated fat, and cholesterol have been associated with consumption of dried fruit and purple/blue fruit and vegetables among adults (Keast and others 2011; McGill and others 2011). Grape products included in this analysis contributed to dietary nutrient density. Among adults, compared to NGC, GC had significantly higher intakes of 7 nutrients that the 2010 Dietary Guidelines Advisory Committee (DGAC) identified as “tenuous for adult men and women” which were dietary fiber, vitamin A, vitamin C, vitamin E, calcium, magnesium, and potassium (Report of the DGAC 2010). Adult GC also had higher intakes than NGC of thiamin, vitamin B6, total folate and iron. Compared to NGC among children, GC had higher intakes of dietary fiber, vitamin A, vitamin C, riboflavin, vitamin B6, calcium, phosphorus, magnesium, and potassium. The DGA 2010 recommends increased intakes of 4 key nutrients: potassium, dietary fiber, calcium, and vitamin D (USDA and HHS 2010). In this analysis, among both children and adults, GC had higher intakes than NGC of 3 of these nutrients: dietary fiber, potassium, and calcium. Higher intakes of key nutrients have been associated with purple/blue produce and 100% grape juice consumption among children and adults (McGill and others 2011) and with dried fruit consumption among adults (Keast and others 2011). Grape product consumption was associated with higher intakes of calcium among children and adults in this analysis, even though fruit is not a good source of calcium. This indicates that fruit intake may be a marker for a healthier overall dietary pattern.
In this study, compared to NGC, GC had higher intake of several key nutrients, however mean intakes of dietary fiber and potassium were still below the currently recommended Dietary Reference Intake amounts. The recommended intake of dietary fiber is 25 to 38 g depending on age (4 y and above) (Inst. of Medicine 2002). Fiber intake by GC was 13.9 ± 0.3 g/d among children, and 17.8 ± 0.3 g/d among adults, which are approximately half of the recommended amounts. The Adequate Intake (AI) recommendation for potassium ranges from 3000 to 4700 mg/d for the U.S. population age 1 and above (Inst. of Medicine 2004). Mean potassium intake by all groups of children and adults included in this study were below the age-appropriate AI recommendation. Fresh and dried fruit are good sources of dietary fiber and along with 100% juice make an important contribution to dietary potassium intake (USDA and HHS 2010; Nutrition for Everyone 2012; USDA Natl. Nutrient Database for Standard Reference 2012 Release 24).
This study has several strengths and limitations. NHANES is a cross-sectional survey and does not provide longitudinal data, thus cause-and-effect relationships such as an association of intake with health could not be determined. Diet data were collected using the 24-h recall method, which may be subject to recall bias; however, a single 24-h recall is sufficient to compare mean nutrient intakes of groups (Thompson and Byers 1994). Another strength is that NHANES is a large observational study of a nationally representative sample of the U.S. population that allows the assessment of numerous nutritional outcomes.
Among children and adults, consumers of common grape products (fresh grapes, raisins, and 100% grape juice) had healthier dietary patterns and higher intakes of key nutrients than NGC. Among both age groups, grape product consumption was associated with significantly higher HEI-2005 scores, higher intakes of total and whole fruit, and lower intakes of solid fat, added sugars, and SoFAAS calories. Compared to NGC, GC had higher intakes of dietary fiber, calcium, and potassium, which are nutrients that are encouraged by the 2010 DGA. Among adults, GC also had higher intakes than NGC of other nutrients identified by the 2010 DGAC as “tenuous for adult men and women” which include vitamin A, vitamin C, vitamin E, and magnesium. Grape products can make a significant contribution to a healthy diet pattern and dietary nutrient density. Consumption of fruit in all forms should continue to be encouraged for the U.S. population.
This study was supported by National Grape & Wine Initiative, Sacramento, CA, U.S.A.