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An Increasing Problem…
For the past twenty years, the United States has been struggling with an obesity epidemic. There have been distressing increases in the prevalence of overweight individuals (both adults and children). This is important to stop because obesity can lead to a variety of serious illnesses, physical and psychological, such as Type II diabetes, hypertension, some cancers, and low-self esteem. Thus it has been of utmost importance to instill a proper knowledge of nutrition in children and young adolescents so that future generations may start with healthy habits and perhaps bring an end to the obesity epidemic and its subsequent effects.
What is Obesity?
Obesity is a range of weight that is greater than what is generally considered healthy for a given height. It can be measured in multiple ways, but the most common is Body Mass Index (BMI), which is calculated using weight and height. The CDC (Centers for Disease Control and Prevention) labels “overweight” as those whose BMI falls between 25 and 29.9 and obese as those whose BMI is 30 or higher (http://www.cdc.gov/nccdphp/dnpa/healthyweight/assessing/index.htm). Based on BMI, obesity can also be determined in the form of percentiles, which can be predicted using the charts shown (girls in pink and boys in blue, taken from http://www.cdc.gov/nchs/about/major/nhanes/growthcharts/clinical_charts.htm). The AAP (American Academy of Pediatrics), which considers those with a BMI between the 85th and 95th percentile for age and sex to be overweight and with a BMI equal to or more than the 95th percentile to be overweight or obese (“The Use and Misuse of Fruit Juice in Pediatrics”, 2001). The causes of obesity are due both to genetic factors, such as ethnicity and genomic makeup, as well as environmental factors, like the amount of physical activity a person engages in weekly or their everyday diet. Because it is very difficult to control the genetic makeup of a person at this moment, there has been a great emphasis on influencing external factors and changing behavior like increasing the amount of exercise, eliminating trans fat in restaurants, changing crucial dietary choices of individual, etc…
Focus on Dietary Changes: What does a human body need?
In an attempt to counteract the obesity epidemic and help maintain healthy, functional bodies, the US government, in particular the Dietary Guidelines for Americans, has established a nutritional guideline, which is taken from http://www.disabled-world.com/artman/publish/food_pyramid.shtml). Although it is not absolutely accurate, it does serve as a good rough guideline for the amount of food that fulfills the body’s daily need for nutrients, which in turn helps the cells in our body function properly. For instance, the recommended daily intake of fruit for children (ages 1-4) is about 1 to 1½ cups, which can be 1 cup of fresh fruit, ½ a cup of dried fruit or 1 cup of 100% juice (http://www.mypyramid.gov/pyramid/fruits.html). The AAP further recommends that the intake of fruit juice be limited to 4-6 oz/day for 1 to 6 year olds and 8-12 oz/day for 7 to 18 year olds because an excess amount of juice can lead to malnutrition as well as diarrhea, tooth decay, and flatulence (“The Use and Misuse of Fruit Juice in Pediatrics”, 2001). This serving of fruit will fulfill several nutrient requirements, such as potassium, dietary fiber, vitamin C and folate (folic acid). Ultimately consuming these nutrients will help maintain healthy blood pressure, reduce blood cholesterol levels, lower risk of heart disease, facilitate proper bowel functions, and bolster growth and repair of body tissues (http://www.mypyramid.gov/pyramid/fruits_why.html).
What can be considered a 100% fruit juice?
The Food and Drug Administration’s definition for different beverages, including juice, is listed below.
100% Pure or 100% Juice
Guarantees only 100 percent fruit juice, complete with all its nutrients. If it's not there, it's not all juice.
"Cocktail," "Punch," "Drink," "Beverage"
Terms which signify diluted juice containing less than 100 percent juice, often with added sweeteners.
Fresh Squeezed Juice
Squeezed from fresh fruit. It is not pasteurized and is usually located in the produce or Adairy section of the grocery store.
Water is removed from whole juice to make concentrate; then water is added back to reconstitute to 100 percent juice or to diluted juice such as lemonade.
Not From Concentrate
Juice that has never been concentrated.
Freshly squeezed, and packaged and frozen without pasteurization or further processing. It is usually sold in plastic bottles in the frozen food section of the grocery store and is ready to drink after thawing.
Juice on Unrefrigerated Shelves
Shelf-stable product usually found with canned and bottled juices on unrefrigerated shelves of your store. It is pasteurized juice, or diluted juice, often from concentrate, packaged in sterilized containers.
Heated and sealed in cans to provide extended shelf life of more than one year.
The most important terms to note are 100% Pure or 100% Juice, which “guarantees only 100% fruit juice, complete with all its nutrients” and cocktail, punch, drink or beverage, which are considered “diluted juice containing less than 100% juice, often with added sweeteners.” 100% fruit juice contains only natural sugars:
The beverage cannot be considered 100% fruit juice if it does contain additional artificial sugars:
· white sugar
· brown sugar
· corn syrup
· high-fructose corn syrup
· malt syrup
· fructose sweetener
· liquid fructose
So what are the effects of 100% fruit juice consumption in children? Is it as beneficial as fresh fruit in terms of providing enough nutrients? And does consuming 100% fruit juice contribute to obesity in children? Is drinking 100% fruit juice more beneficial than artificially sweetened fruit juice?
On the Internet and in the News…
This controversy is still a very pertinent issue among scientific researchers and the general public. There are many conflicting views on whether fruit juice is as healthy as fruit and if it contributes to obesity.
Are there Benefits in 100% Fruit Juice?
The conclusions to this question vary between two extremes. One website claims that 100% fruit juice is a convenient way to get a proper serving of fruit, and it may even be better than fresh fruit because it contains a higher amount of nutrients than whole fruits, such as “vitamin C, folate and potassium….[and] phytochemicals” (http://www.fruitjuicefacts.org/pr_release18.html). Because it is made by the Juice Products Association (JPA), a “trade association representing the fruit and juice products industry … processors, packers, extractors, brokers and marketers of fruit and vegetable juices, juice beverages, fruit jams, jellies and preserves and similar products,” these praises for fruit juice must be taken with a grain of salt (http://www.juiceproducts.org/aboutjpa.html). Fruitfacts.org selectively displays the advantages of fruit juice from various scientific papers without evaluating each study cautiously and critically, showing only information that bolsters the good effects of their products; and thus by misleading and possibly misinforming the consumers, they goad the customers to buy more juice. In contrast, John Hopkins, which has a rather famous hospital and a reputable name in the field of medicine approaches the issue differently. The information on this website acknowledges that there is a conflict in information and mainly discourages the consumption of fruit juice, pushing for fresh fruit, claiming juice has “empty calories” and should not be consumed in excessive amounts, instead it recommends consuming it in moderation. Because of their prestige, it seems this source of information is more trustworthy, in terms of informing the patient or internet user. Although the website does not evaluate each study very critically, they at least look at different points of views (http://www.hopkinsbayview.org/healthydirections/stayinghealthy/kids/juice.html).
Is there a link to obesity?
Once again from the JPA, we see a claim that the “majority” of research did not show a connection between weight gain and childhood obesity. They do not state specific facts, but cling to the study that shows their product’s possible effects (http://www.fruitjuicefacts.org/pr_release18.html). However, there are a variety of websites that try to include more specific details about the scientific studies, though they are not usually cited or identified. WebMD, an informative website for a curious and physically aware individual, summarizes neatly for the casual internet user that 100% juice may not increase the weight of a child. They even speak directly to Dr. Nicklas, who a major figure in researching the links between childhood obesity and fruit juice. However, there is no real critical analysis or expert opinion on the matter, just a presentation of the results and conclusions of Dr. Nicklas’ study, which could hinder the viewer’s ability to critically assess the study (http://children.webmd.com/news/20070508/100-percent-juice-may-not-boost-kids-weight). And we also see that Johns Hopkins similarly writes a brief summary of the study, though again we see a lack of critical approach. This time, excessive juice drinking (more than 12 ounces of juice) is linked to shorter and more obese children (http://www.hopkinsbayview.org/healthydirections/stayinghealthy/kids/juice.html). Finally in many news sources we see an active discussion on 100% fruit juice and its possible associations with obesity. For instance, an article from the UK discusses the effects of sugar on our body: does naturally occurring sugars, such as fructose, contribute to obesity, or do artificial sugars, such as high fructose corn syrup, contribute to weight gain? Of course, the article keeps the reader’s interest and gets the main message across that too much sugar could potentially make one overweight. However it lacks a depth and specificity in its definitions, for instance they never define “fat” or put a clear distinction in their interchangeable use of “fructose” (http://www.dailymail.co.uk/health/article-1029501/Can-fruit-make-fat-Natural-sugar-fruit-fuelling-nations-obesity-epidemic.html). Though overall it seems with more objective sites, like WebMD, news sources, and websites, serving their patients, there is a more objective approach and gives an informative summary of a particular study as it comes out. But websites like those of JPA, which are more oriented towards business and bolstering the image of juice as healthy, find it more convenient to present only evidence that shows their product in the best light, thus showing that it meets the health standards and may even exceed them. Now it is time to delve into our own critical analysis of these questions by examining the scientific breadth done on the effects of 100% fruit juice.
There have been a number of studies examining the relationship between nutritional intake and 100% fruit juice consumption. One of the most striking is that of Nicklas, O’Neil, and Kleinman (2008), who examined both weight gain and nutrient intake. They first split the participants into groups depending on age and juice consumption – there were 4 juice groups (>0 to ≤6 fl oz/d, >6 to ≤12 fl oz/d, >12 fl oz/d, and nonconsumers) and 3 age groups (2-3, 4-8, and 9-11 years old). Their data collection was through a single 24 hour dietary interview method, where the dietary intakes of the child were reported by either the caretaker or the child with the assistance of an adult. These habits of consumption were statistical analyzed with nutrient intake, obesity measurements, and food-group intake. They were then weighted against the NHANES [National Health and Nutritional Evaluation Survey, which is an “ongoing data-collection initiative to obtain information about the health and diet of a cross-sectional, nationally representative US sample” (Nicklas et al., 2008, 558)] examination sample weights. They found that mean daily juice consumption was 4.1 fluid oz, which had about 58 kcal, or 3.3% of total caloric intake. The results showed that there was not necessarily an increase in BMI (as shown in the following table, taken from Nicklas et al., 2008). But there was an increase in energy intake, higher ingestion of fresh fruit, which the paper credits the factors of taste and availability, and a lower consumption of total fat, saturated fatty acids, added sugar, and discretionary fat. There was also an increase in nutrient intake by consumers of juice, as shown in the table from the paper below (one can see that Vitamin C increases from 60.3 mg for those who do not consume any juice to 180.2 mg for those who consume more than 12 oz/day).
However, there are many issues that need to be addressed in this study. For instance, because this study is done in a cross-sectional manner, meaning it is over a brief period of time, we cannot define any correlation, cause and effect, or examine the long term effects of drinking 100% fruit juice, so a longitudinal study would highly suggested.
There have been other earlier contradictory studies, such as Dennison, Rockwell, and Baker (1997), in which 100% fruit juice has been associated closely with weight gain and a shorter stature. In this study, they took a small sample of 225 children ages 2 and 5 from a general primary practice in upstate New York. The population was 97% white and their socioeconomic status ranged from the lower to middle class. Their results showed that 19 pre-school aged children drank an excessive amount of fruit juice (more than 12 oz/day). The graph from their paper, which is shown here illustrates that the excess consumption of juice increases the percentage of overweight children – there was a higher means BMI for children who consumed more than 12 oz/day (32% were overweight) than those that consumed less than 12 oz/day (9% were overweight). However this study has been criticized and discredited as biased because it has such a small and selective population and their definitions for obesity are not the same (the study considers a BMI ≥ 90% as obese, while other studies have defined obesity with a BMI ≥ 95%). Also the study only investigated the effects of apple juice, which has high fructose and sucrose content. And it has been suggested that this may not be true for other fruit juices. And finally, this again is a cross-sectional study, which would not directly correlate juice consumption with weight as this paper had suggested.
To resolve the issue of longitudinal studies, Skinner and Carruth (2001) investigated 72 children, who were continuous participants in a longitudinal study from 1992 to 1999. These children were white and were of the middle to upper class. Data was collected through 7 in-home interviews with two 24 hour recalls and two food records for children between 24 and 72 months. The results were both genders consumed approximately 5.4 oz/day, which decreased as the children aged. The authors state the longitudinal juice intake was not related to BMI, and interestingly the children who had consumed more than 12 oz/day early in their lives showed a significant decrease in BMI than the group who had less than 12 oz/day. While these results are interesting, this study raises issues about sample bias, which was relatively small both in size, limited in geographic location, and not very diverse ethnically or socioeconomically.
Finally, we will investigate drinks with added sugar and the possible benefits of consuming natural sugars. A comprehensive review of 15 cross-sectional by Malik, Schulze, and Hu (2006), 10 prospective, and 5 experimental studies showed that that there is a positive correlation between greater consumption of sugar-sweetened beverages and weight gain in children. Their method of study consisted of searching on the MEDLINE database for cross-sectional, prospective cohort, and experimental studies. In an organized table Malik et al. (2008) shows that there is a generally positive trend between intake of sugar-sweetened beverage and overweight or obesity in all three of the investigated studies, but the experimental studies were of great interest. For instance one contained a cluster-randomized controlled trial in school children, which showed that an educational program in school was successful in reducing the consumption of sugary drinks and in turn the prevalence of obesity. There was also another experimental study that randomly assigned participants to an intervention group or a controlled group. This study showed that sugar consumption decreased by 82% in the experimental group, but did not change in the control, which ultimately led to a beneficial effect for the experimental group. Interestingly they reported that fruit juice, irrespective of type did not influence weight gain longitudinally, suggesting that artificial sugar has a great impact on obesity and that perhaps natural sugars, and thus 100% fruit juice, would not contribute to childhood obesity. Ultimately, they conclude that artificial sugars may have a biological mechanism to both weight gain and diseases associated with obesity, such as high fructose corn syrup may have a very specific role in diabetes. Nonetheless their study could have been more specific on the limitations of each study, such as a consistent age group.
In the end…
After intensively investigating the studies on the effects of 100% fruit juice in children’s diets, there is still an uncertain conclusion – there is no absolute association between consumption of 100% fruit juice and childhood obesity. Though it seems in most studies, weight gain is not commonly associated with drinking 100% fruit juice. Also 100% fruit juice does seem to be a very convenient and appealing way for children and adults alike to get the nutrients that fruits often provides them, such as Vitamin C, folate, and potassium. However, fruit in beverage form lacks dietary fiber, which is important for the regulation of the digestive system. Thus the elimination and complete replacement of fresh fruit with 100% fruit juice is not advisable. It is good to allow children to drink 100% fruit juice because it has shown that they have a better nutrient intake, but it should acts as a supplement and occasional replacement for fresh fruit. And if at all possible, avoid drinks with added sugar. In the end as the Greeks would advocate, everything, including juice drinking, needs to be done in moderation, in order to be at optimal health.
1. American Academy of Pediatrics. (2001). The Use and Misuse of Fruit Juice. Pediatrics (107)5: 1210-1213.
2. Dennison, B.A., Rockwell, H.L., & Baker, S.L. (1997). Excess fruit juice consumption by preschooled-aged children is associated with short stature and obesity. Pediatrics, 99(1):15-22.
3. Malik, V.S., Schulze, M.B., & Hu F.B. (2006). Intake of sugar-sweetened beverages and weight gain: A systematic review. American Journal of Clinical Nutrition, 84: 274-88.
4. Nicklas, T.A., O'Neil, C.E., & Kleinman R. (2008). Associaiton between 100% juice consumption and nutrient intake and weight of children aged 2 to 11 years. Archives of Pediatrics & Adolescent Medicine, 162 (6): 557-65.
5. Skinner, J.D. & Carruth, B.R. (2001). A Longitudinal study of children's juice intake and growth: The juice controversy revisited. Journal of the American Dietetic Association, 101 (4): 432-7.
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