Research on 100 % fruit juice

A number of observational studies have investigated the relationship between 100 % FJ intake and anthropometric measures in children and/or adolescents. A comprehensive review article published in 2008 evaluated the results of twenty-one studies (nine cross-sectional and twelve longitudinal)⁽ Reference O’Neil and Nicklas ^{14 )}. Only three out of nine cross-sectional studies and three out of twelve longitudinal studies reported a positive association between 100 % FJ intake and weight status. After critically reviewing the quality of the studies, the authors concluded that there was no systematic association between 100 % FJ intake and body weight in children or adolescents. As analysed in the review, three longitudinal studies reported significant associations between 100 % FJ intake and weight or BMI in adolescent girls in Germany⁽ Reference Libuda, Alexy and Sichert-Hellert ^{15 )} or low-income children who were overweight or at risk for overweight at baseline in the USA⁽ Reference Faith, Dennison and Edmunds ^{16 ,} Reference Welsh, Cogswell and Rogers ^{17 )}. The two latter studies included relatively large sample sizes, yet none of the three studies used a nationally representative sample. Observational studies concerning FJ intake and anthropometric measures in children and adolescents published since the 2008 review are summarized in Table 1. Several cross-sectional and longitudinal studies published since the 2008 review report no association between 100 % FJ consumption and obesity or BMI in children and adolescents, including Mexican-American children in California⁽ Reference Beck, Tschann and Butte ^{18 )}, Swedish adolescents⁽ Reference Vagstrand, Linne and Karlsson ^{19 )}, Greek schoolchildren⁽ Reference Papandreou, Andreou and Heraclides ^{20 )}, Canadian children⁽ Reference Danyliw, Vatanparast and Nikpartow ^{21 )}, children in a California WIC (Special Supplemental Nutrition Program for Women, Infants, and Children)⁽ Reference Davis, Koleilat and Shearrer ^{22 )}, and adolescents in Project EAT (Eating Among Teens)⁽ Reference Vanselow, Pereira and Neumark-Sztainer ^{23 )} and the National Health and Nutrition Examination Survey (NHANES)⁽ Reference O’Neil, Nicklas and Kleinman ^{24 )}. A multi-year and multi-state analysis of over 272 000 adolescents from the Youth Risk Behavior Survey reported an inverse association between 100 % FJ intake and BMI in girls and a null association in boys⁽ Reference Taber, Stevens and Poole ^{25 )}. These results should be interpreted with caution since height and weight were self-reported and adolescent females tend to under-report their weight⁽ Reference Clarke, Sastry and Duffy ^{26 ,} Reference Sherry, Jefferds and Grummer-Strawn ^{27 )}. One longitudinal study reported a significant association between the amount of FJ consumed by children at age 1 year and BMI Z-score during early and mid-childhood⁽ Reference Sonneville, Long and Rifas-Shiman ^{28 )}, while an inverse association was reported between fruit and vegetable juice intake during childhood and waist circumference and skinfold measurements in adolescence⁽ Reference Hasnain, Singer and Bradlee ^{29 )}. Two recent reviews of the literature, including an analysis by a workgroup on behalf of the Academy of Nutrition and Dietetics’ Evidence Analysis Library, concluded that the majority of evidence does not support an association between 100 % FJ consumption and weight status or adiposity in children 2–18 years of age^{( 30 ,} Reference O’Neil and Nicklas ^{31 )}. Readers desiring more detailed information about individual studies should consult these reviews.

Table 1 Observational studies published since 2008 evaluating fruit juice intake and anthropometric measures in children and adolescents

NHANES, National Health and Nutrition Examination Survey; WIC, Special Supplemental Nutrition Program for Women, Infants, and Children; EAT, Eating Among Teens; fl oz, fluid ounces (1 fl oz=29·57 ml); Ht, height; Wt, weight; WC, waist circumference; FJ, fruit juice; CDC, Centers for Disease Control and Prevention; IOTF, International Obesity Task Force; %BF, percentage body fat; PA, physical activity; SES, socio-economic status; T2, time 2; TV, television; %E, percentage of energy intake.

For adults, no association between 100 % FJ consumption and waist circumference was observed in the Coronary Artery Risk Development in Young Adults (CARDIA) longitudinal cohort⁽ Reference Duffey, Gordon-Larsen and Steffen ^{32 )}, while inverse associations between 100 % FJ and BMI have been reported in other studies⁽ Reference Akhtar-Danesh and Dehghan ^{33 ,} Reference Pereira and Fulgoni ^{34 )}. However, a large study using the Nurses’ Health Study I and II, and Health Professionals Follow-Up Study cohorts reported a significant and positive association between the increase in FJ intake and weight gain of about 0·15 kg (0·3 lb) in adults over each 4-year follow-up study period⁽ Reference Mozaffarian, Hao and Rimm ^{35 )}. Demographic, sample size or other differences between cohorts may account for the differences in results. Overall, the results of observational studies in children and adults on 100 % FJ intake and body weight are mixed with the majority of studies reporting no association. Randomized clinical trials are lacking and needed to determine the existence of a causal relationship.

Study results are also mixed for associations between 100 % FJ intake and risk for type 2 diabetes, with the majority of studies reporting no significant effects. 100 % FJ intake was positively associated with risk of type 2 diabetes in several studies, including middle-aged women in the Nurses’ Health Study⁽ Reference Bazzano, Li and Joshipura ^{36 )}, middle-aged Chinese men and women living in Singapore⁽ Reference Odegaard, Koh and Arakawa ^{37 )}, and in an analysis of three large US health professional cohorts (including the Nurses’ Health Study as previously analysed and reported in Bazzano et al.)⁽ Reference Muraki, Imamura and Manson ^{38 )}. However, a systematic review and meta-analysis evaluating four prospective cohort studies representing over 137 000 participants concluded that the intake of 100 % FJ was not significantly associated with the risk for type 2 diabetes⁽ Reference Xi, Li and Liu ^{39 )}. FJ intake was not associated with risk for incident type 2 diabetes in studies in African-American women⁽ Reference Palmer, Boggs and Krishnan ^{40 )}, Japanese-Brazilians⁽ Reference Sartorelli, Franco and Gimeno ^{41 )}, Japanese⁽ Reference Eshak, Iso and Mizoue ^{42 )}, middle-aged women in the Nurses’ Health Study II cohort⁽ Reference Schulze, Manson and Ludwig ^{43 )}, French women⁽ Reference Fagherazzi, Vilier and Sartorelli ^{44 )} and healthy men in the Health Professionals Follow-Up Study cohort⁽ Reference de Koning, Malik and Rimm ^{45 )}. No association between pre-pregnancy FJ intake and risk for gestational diabetes was reported for women in the Nurses’ Health Study II⁽ Reference Chen, Hu and Yeung ^{46 )}. An analysis of the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort reported no association between the consumption of juices and nectars and the incidence of type 2 diabetes in over 11 000 subjects^{( 47 )}. In this analysis, the juice group also included vegetable juices as well as nectars that may have contained up to 20 % added sugars, so results should be interpreted with some caution. European men and women without diabetes consumed higher amounts of juice compared with those with diabetes⁽ Reference Nothlings, Boeing and Maskarinec ^{48 )}.

Metabolic syndrome is a cluster of risk factors that increase the risk for CVD and diabetes⁽ Reference Alberti, Eckel and Grundy ^{49 )}. Studies using the cross-sectional NHANES⁽ Reference Pereira and Fulgoni ^{34 )} and longitudinal CARDIA⁽ Reference Duffey, Gordon-Larsen and Steffen ^{32 )} data sets report no association between 100 % FJ intake and risk for metabolic syndrome. A study of over 1100 adults from the Bogalusa Heart Study reported that 100 % FJ intake was higher in those with no risk factors for metabolic syndrome v. those having one or two risk factors⁽ Reference Yoo, Nicklas and Baranowski ^{50 )}. Substituting sugar-sweetened beverages with moderate amounts of homemade FJ was associated with a 30 % decreased risk for metabolic syndrome among Costa Rican adults⁽ Reference Mattei, Malik and Hu ^{51 )}. An analysis of NHANES 2003–2006 data reported a 36 % reduced odds or likelihood for metabolic syndrome in men who consumed orange juice compared with men who did not consume orange juice, with a null association in women⁽ Reference O’Neil, Nicklas and Rampersaud ^{52 )}. FJ intake has been associated with an increased risk for impaired glucose tolerance in a Japanese-Brazilian population⁽ Reference Sartorelli, Franco and Gimeno ^{41 )}, but has been inversely related to fasting glucose in the Framingham Offspring cohort⁽ Reference Yoshida, McKeown and Rogers ^{53 )}.

Intake of 100 % FJ does not appear to have adverse effects on blood lipids and may be beneficial in some cases. FJ consumption was not associated with significant effects on total cholesterol, LDL-cholesterol or HDL-cholesterol in a meta-analysis of nineteen randomized controlled studies⁽ Reference Liu, Xing and Chen ^{54 )}. A study using the CARDIA cohort reported no association between FJ intake and the CVD risk factors elevated TAG, elevated LDL-cholesterol or low HDL-cholesterol in adults⁽ Reference Duffey, Gordon-Larsen and Steffen ^{32 )}. Substituting sugar-sweetened beverages with moderate amounts of homemade FJ was associated with increases in HDL-cholesterol⁽ Reference Mattei, Malik and Hu ^{51 )}. Clinical studies have reported beneficial effects on blood lipids of some individual juices including orange juice and LDL-cholesterol⁽ Reference Basile, Lima and Cesar ^{55 ,} Reference Cesar, Aptekmann and Araujo ^{56 )} and grapefruit juice and HDL-cholesterol⁽ Reference Silver, Dietrich and Niswender ^{57 )}.

Nutritional and other benefits

100 % FJ are nutrient-dense beverages that provide a variety of vitamins and minerals in varying amounts depending on the juice type, including vitamin C, potassium, thiamin, vitamin B₆, folate and vitamin A, as well as calcium and vitamin D in some fortified juices. 100 % FJ are also sources of flavonoids, including polyphenolic compounds that may confer health benefits⁽ Reference Hooper, Kroon and Rimm ^{58 ,} Reference Vauzour, Rodriguez-Mateos and Corona ^{59 )} and are readily found in a variety of 100 % FJ. Consumption of 100 % FJ has been positively associated with the intake of key nutrients, such as vitamin C, folate, potassium and magnesium⁽ Reference O’Neil, Nicklas and Kleinman ^{24 ,} Reference Nicklas, O’Neil and Kleinman ^{60 ,} Reference O’Neil, Nicklas and Zanovec ^{61 )}, which have been identified as underconsumed nutrients or nutrients of concern (potassium) in the 2010 Dietary Guidelines for Americans^{( 62 )}. Intake of 100 % FJ also has been associated with enhanced diet quality based on Healthy Eating Index scores⁽ Reference O’Neil, Nicklas and Zanovec ^{63 )}. Approximately 60 % of children 4–8 years of age and at least 80 % of older children and adults do not meet fruit intake recommendations⁽ Reference Krebs-Smith, Guenther and Subar ^{64 )}. While whole fruit should be chosen first, 100 % FJ can complement whole fruit and, when consumed in appropriate amounts, is a practical strategy to help Americans meet daily fruit intake recommendations. In fact, 100 % FJ consumers have been reported to have higher intakes of whole fruit than non-consumers⁽ Reference O’Neil, Nicklas and Kleinman ^{24 ,} Reference Muraki, Imamura and Manson ^{38 ,} Reference Nicklas, O’Neil and Kleinman ^{60 )}, suggesting that 100 % FJ is complementary to, and not a replacement for, whole fruit in the diet.

From strictly an economic standpoint, 100 % FJ can have advantages over whole fresh fruit. Based on data from the US Department of Agriculture’s Agricultural Marketing Service^{( 65 )}, the average price for a non-organic navel orange for the time period 19 September 2014 to 26 December 2014 was $US 0·81. Based on Nielsen Scantrack data, the season-to-date (28 September 2014 to 17 January 2015) price for reconstituted orange juice was $US 4·99/gallon^{( 66 )}, or approximately $US 0·31 for 8 fl oz (237 ml), making an 8 fl oz (237 ml) serving of 100 % orange juice just over one-third the cost of a fresh orange in a practical serving-to-serving comparison. These cost differences could be consequential for lower-income individuals, many of whom have lower intake levels of fruit⁽ Reference Grimm, Foltz and Blanck ^{67 )}, poorer diet quality⁽ Reference Hiza, Casavale and Guenther ^{68 )} and may be at increased risk for chronic disease⁽ Reference Seligman, Laraia and Kushel ^{69 )}, as well as institutions such as day-care centres, child or adult feeding programmes and schools that purchase and serve food and beverage items in large quantity. The longer shelf-life of 100 % FJ compared with most fresh fruits may also help reduce food waste.

As with any caloric food or beverage, it is important that 100 % FJ be consumed in appropriate amounts that do not contribute to excessive energy intake. The American Academy of Pediatrics^{( 70 )} and the American Heart Association⁽ Reference Johnson, Appel and Brands ^{71 )} have suggested guidelines and limits for juice intake in children: 4–6 fl oz/d (118–177 ml/d) for children 1–6 years of age and 8–12 fl oz/d (237–355 ml/d) for older children and adolescents. Juice should not be given to infants 6 months of age and younger and should never be given in a bottle. The Robert Wood Johnson Foundation has issued beverage guidelines for children and adults, with recommended 100 % FJ amounts similar to but slightly more restrictive than those of the American Academy of Pediatrics^{( 72 )}. Some data suggest that sugar-sweetened beverages (not including 100 % FJ) may be displacing milk from the diet⁽ Reference Lasater, Piernas and Popkin ^{73 ,} Reference Blum, Jacobsen and Donnelly ^{74 )}. This does not appear to be true with 100 % FJ as children and adolescents who consumed 100 % FJ did not consume significantly less milk compared with non-consumers⁽ Reference O’Neil, Nicklas and Kleinman ^{24 ,} Reference Nicklas, O’Neil and Kleinman ^{60 )}. A study examining changes in sweetened beverage, milk and juice consumption in children between the 5th and 8th grades reported that milk and juice were complements to each other, suggesting that 100 % FJ did not displace milk from the diet⁽ Reference Oza-Frank, Zavodny and Cunningham ^{75 )}. Children consuming 100 % FJ may be considered to have healthier diets because they had higher intakes of several vitamins and minerals and lower intakes of total and saturated fat than non-consumers⁽ Reference O’Neil, Nicklas and Kleinman ^{24 ,} Reference Nicklas, O’Neil and Kleinman ^{60 )}.

Summary

There is no consistent evidence that 100 % FJ is independently associated with adverse impacts on weight; in fact, many studies report null associations or inverse associations between 100 % FJ intake and body weight measures. However, the lack of randomized controlled clinical trials precludes the existence of a cause-and-effect relationship between 100 % FJ intake and weight or body composition measures. Studies related to 100 % FJ and type 2 diabetes are equivocal and reinforce the need for more research in this area. That 100 % FJ intake does not appear to be associated with key risk factors for diabetes such as insulin resistance or metabolic syndrome raises questions about the nature of the positive association between 100 % FJ intake and diabetes risk reported in some studies. Given the complex aetiology of diabetes, cross-sectional studies cannot account for all aspects of diet and lifestyle that could impact the development of these conditions; and further research is warranted. Studies on 100 % FJ intake are often confounded by the nature of the beverages included in the category defined as ‘juice’. For example, studies may combine the intakes of 100 % FJ and juice drinks and beverages that are not 100 % juice, may contain added sugars and have significantly different nutritional profiles compared with 100 % FJ. Self-reported dietary intake data further confound this issue as consumers may not recognize which products are 100 % FJ and which are not, increasing the likelihood that 100 % FJ intake is misreported. Future research should consider and address these issues.

Overall, there appears to be no reported adverse effects of 100 % FJ consumption on health conditions often associated with excess sugar or fructose intake; some studies report benefits. 100 % FJ has been associated with nutritional benefits and with diets that are of higher quality or more nutritionally complete. The amount of 100 % FJ consumed should be balanced with overall energy intake and expenditure. Intake should especially be monitored in children, particularly those who are overweight or obese. Consumption of 100 % FJ can help satisfy several key recommendations in the 2010 Dietary Guidelines for Americans: specifically, a focus on consuming nutrient-dense foods and beverages, increasing fruit intake and achieving nutrient adequacy. Data suggest that the consumption of 100 % FJ in appropriate amounts would be beneficial rather than detrimental to health.