Science Questions with Surprising Answers[Menu]

Is fruit juice healthier than whole fruit?

Category: Health
Published: December 2, 2013

By: Christopher S. Baird, author of The Top 50 Science Questions with Surprising Answers and physics professor at West Texas A&M University

No, fruit juice is not healthier than whole fruit in general. Even if the juice is freshly squeezed on the spot, drinking the juice is less healthy than eating the fruit whole. You may be tempted into thinking that since fruit juice comes straight from the fruit, they must be nutritionally equivalent. But such thinking is wrong. There are two main reasons for this discrepancy.

red apple
Whole fruits are significantly healthier than fruit juice. Public Domain Image, source: Christopher S. Baird.

First, the pulp and skin of the fruit that is left behind is high in dietary fiber. Dietary fiber plays a larger role than just promoting regular bowel movements. When you eat a fruit whole, the dietary fiber in the pulp binds to the natural sugar in the fruit as it travels through your gastrointestinal tract. This binding action makes it harder and take longer for your body to absorb the sugar. As a result, the fruit's sugar accumulates in your blood at a lower and slower rate if you eat the fruit whole than if you drink straight fruit juice. This process lets your body use the sugar more as a direct energy source. In contrast, drinking straight fruit juice leads to a spike in blood sugar. Sensing that you have more sugar than you need, your body quickly releases insulin, leading to a large amount of the sugar in your blood being converted to fat and glycogen. In this way, the blood sugar spike leads to a blood sugar dip (unless more food is eaten), leaving you hungry again. And being hungry makes you eat more. In this way, drinking pure fruit juice leads to poorer regulation of blood sugar and increased calorie consumption, when compared to eating whole fruits. People who are especially sensitive to blood sugar levels may even suffer headaches, weakness, and irritability after drinking fruit juice, whereas these symptoms do not arise when eating the fruits whole.

A study lead by L. F. Burroughs published in the American Journal of Clinical Nutrition states, "Healthy volunteers ingested sugar-equivalent meals of oranges and orange juice and of grapes and grape juice. Satiety, assessed by two subjective scoring systems, was greater after whole fruit than after juice and the return of appetite was delayed. With oranges, as previously reported with apples, there was a significantly smaller insulin response to fruit than to juice and less postabsorptive fall in plasma glucose." Interestingly, a study lead by H. H. Stratton and published in the journal Pediatrics found that, "Among children who were initially either at risk for overweight or overweight, increased fruit juice intake was associated with excess adiposity gain, whereas parental offerings of whole fruits were associated with reduced adiposity gain."

Secondly, the pulp and skin of many fruits tends to be high in vitamins and other nutrients. Extracting just the juice leaves behind much of these nutrients. For instance, oranges are a rich source of flavonoids, but much of the flavonoids are stored in the pulp and not the juice.

The presence of dietary fiber and other nutrients in the fruit's skin and pulp therefore makes whole fruit significantly healthier than fruit juice. For instance, a study lead by Qi Sun of the Harvard Medical School and published in the British Medical Journal found that:

Replacing each three servings/week of fruit juice consumption with the same amount of total or individual whole fruits, the risk of type 2 diabetes in the pooled analysis was 7% (95% confidence interval 4% to 9%) lower for total whole fruits, 33% (24% to 40%) lower for blueberries, 19% (14% to 24%) lower for grapes and raisins, 14% (11% to 18%) lower for apples and pears, 13% (9% to 16%) lower for bananas, and 12% (8% to 17%) lower for grapefruit after adjustment for personal factors, lifestyle, and the modified alternate health eating index score (figure). Additionally, we found that replacing fruit juice with oranges, peaches, plums, and apricots was also associated with a lower risk of type 2 diabetes: 18% (8% to 28%) lower for prunes, 11% (5% to 16%) lower for peaches, plums, and apricots, and 8% (4% to 12%) lower for oranges.

While drinking 100% fruit juice is certainly healthier than drinking soda pop or fruit-flavored beverages with artificial sweeteners, nothing beats drinking a cup of water and eating a whole fruit raw.

Topics: dietary fiber, digestion, fruit, fruit juice, fruit pulp, insulin, whole fruit