Some say sugar — including natural sugar found in 100-percent fruit juice — is behind the obesity epidemic, responsible for heart disease and causes cancer. Are concerns about sugar overshadowing fruit juice's positive contributions to a healthful diet? Or is 100-percent fruit juice just another sugary drink?
Natural sugars are found in nutrient-rich dairy, vegetables and fruit — key components of a healthy diet. "Added sugars," ranging from controversial high-fructose corn syrup to more than 60 ingredients identified by the U.S. Department of Agriculture, are introduced into foods and beverages by manufacturers during processing or by consumers at the table. And added sugars account for an average of 16 percent of total calories in American diets.
"Diets high in added sugars can lead to weight gain, hypertension and chronic inflammation, and elevate triglycerides and LDL cholesterol," says Rachel Johnson, PhD, RD, nutrition professor at the University of Vermont and past chair of the American Heart Association.
Offering little satiety or nutritional value, sweetened beverages (soda, energy drinks, sports drinks and sweetened "fruit drinks") account for nearly half of the total added sugars consumed by Americans. Although 100-percent fruit juices contain only natural sugars, the human body does not biochemically differentiate between natural and added sugars.
In fact, some juices contain as much sugar as sodas. "Americans drink more apple juice than any other juice," says David Klurfeld, PhD, human nutrition researcher at the U.S. Department of Agriculture. "And nutritionally, it is not much different than soda."
On the other hand, 100-percent fruit juices offer bioactive compounds and nutrients that sodas do not contain. For example, citrus juices such as orange and grapefruit juices provide vitamin C, potassium and — when they include pulp — fiber. In addition, fortified juices become sources of nutrients missing from many diets, such as calcium or folate.
Evidence behind the correlation between fruit juice intake and instances of obesity and diabetes is mixed. Diets with more whole fruits and less fruit juice may reduce risk of Type 2 diabetes, yet a 2014 meta-analysis showed that fruit juice may have no overall effect on fasting glucose and insulin concentrations. Studies also show that children and adults who drink 100-percent fruit juice are more likely to meet daily requirements for vitamins A and C, folate, magnesium and potassium.
The 2010 Dietary Guidelines for Americans recommends 1 cup to 2 ½ cups of fruit per day, with no more than half in juice form. The American Academy of Pediatrics recommends limiting daily fruit juice intake to 4 ounces to 6 ounces for children ages 1 to 6 years, and 8 ounces to 12 ounces for 7- to 12-year-olds. While fruit juice can be a part of a healthful diet, "liquid calories" are easier to over-consume and don't impact fullness as much as solid foods.
"Whole fruit trumps fruit juice because the fibrous content takes longer to chew, promotes a feeling of fullness, slows down digestion and reduces blood sugar spikes commonly seen with fruit juice," says Klurfeld. "There are scores of studies that show people who eat the most fruits and veggies are less likely to be overweight, smoke less, exercise more, don't drink alcohol to excess, eat more whole grains and less meat and added sugar."
To lower sugar and increase fiber in fruit juice, blend whole fruit, suggests Joanne Slavin, PhD, RD, fiber researcher and University of Minnesota nutrition professor. The resulting juice has the same amount of fiber as the whole fruit, and blending fruit with whole vegetables, whole grains or protein can reduce sugar concentration and slow absorption to levels similar to when eating whole fruit.