Fruit? Or Juice?
Health and Wellness
November 26, 2013
Whole fruit is still considered the preferred form of fruit for delivering antioxidants and fiber, compared to fruit juice, according to a recent report from the University of Alabama and published in the Journal of the Academy of Nutrition and Dietetics. This important study comes at a time when the popularity and prevalence of fruit juice in the American diet is on the rise, especially amongst children.
The 2010 Dietary Guidelines (DG2010) for Americans recommend that consumers increase their serving intake of whole fruits and vegetables, but they also define a serving of fruit as 1 cup fruit, 1 cup 100% fruit juice or ½ cup dried fruit. This recommendation has led to a bevy of ready-to-drink beverages on the market, including some that claim they contain a “whole serving of fruit or vegetables”. Previous studies have noted that fruit juice often contains more sugar and less fiber than their whole fruit counterparts, however, few studies have looked specifically at antioxidants and phytonutrient levels and phenolic compounds.
Study author Dr. Kristi Crowe, Assistant Professor at University of Alabama in the Department of Human Nutrition, says that every food should be evaluated for its macronutrient, micronutrient, and non-nutrient phytochemical provision in order that the best choice of food form is selected. Juice is a very controversial topic in nutrition and while it can provide critical micronutrients when consumed as a fruit serving by the DG2010, says Crowe, it may also lack vital phytochemicals.
“The DG2010 recommendation appears to be understood by consumers; however, in light of the gross differences in fruit and juice as mentioned in my research and other studies, it is my scientific opinion that fruit juice is not an equivalent serving to whole fruit,” says Crowe.
In this study, Crowe and her team sought to access the antioxidant density of a single serving of select whole fruit and its 100% juice form for five commonly consumed fruits and juices – grapes, apples, oranges, pineapple and grapefruit. They found that the antioxidant density of apple, orange and grapefruit was 54%, 23% and 52% higher, respectively, than the mean antioxidant density of name brand and store-brand juices for each fruit.
Even within the juices, there were significant differences in antioxidant content, possibly because of the variety of ways fruit juices are produced. For example, fresh apple and grapefruit juice maintained a higher antioxidant content than name-brand or store-brand juices. Many shelf juices that are designed to last longer than a day or two undergo a process that removes flavonoids (plant-based compounds with antioxidant capacity) to prevent browning reactions. Fruit pulp and peel are also removed when making juice, thus further lowering the antioxidant density.
Also, on a per serving basis, 100% grape juice and 100% pineapple juice were actually superior in their antioxidant content as compared to fresh grapes or pineapple, but this is likely a result of weight differential between the two 1-cup serving sizes (a 1-cup serving of fresh grapes is 92 g while a 1-cup serving of 100% grape juice is 240 g).
Whole fruits examined in this study contain approximately 90 calories per serving and between 35% to 61% less sugar than a juice serving, which is significant. Additionally important is the fact that whole fruits may provide greater satiety cues than juice. In other words, a piece of fruit may make you feel full, while a glass of fruit juice may not.
Crowe suggests that practitioners should be advocating the most nutrient-dense foods to promote health and well-being. This entails staying current on the research and understanding the nutrient density of foods.
“Consumption of non-nutrient dense foods, in the case of juice as compared to its whole fruit counterpart, can lead to nutrient deficiencies. With the abundance of free radicals formed endogenously coupled with those encountered in the environment, it is important to consume antioxidant-rich foods to reduce the oxidant load in the body,” she adds.