Is fruit juice healthy or harmful? A source of nutrients ranging from vitamin C to potassium to folic acid (depending on the type of fruit used), fruit juice is undoubtedly a more healthful choice than pop or other sugar-sweetened drinks. But a new study, published in the June edition of the American Journal of Clinical Nutrition, suggests that switching from juice to plain water is associated with a reduction in type 2 diabetes risk. This, combined with previous research suggesting juice consumption could be associated with weight gain, has led a number of researchers and obesity experts to recommend that juice be viewed as more of a treat than a part of a healthy diet.
FRUIT JUICE AND TYPE 2 DIABETES
The new study drew data from some 82,000 women enrolled in the Nurses’ Health Study II. The women were free of diabetes, heart disease and cancer at the start of the study, and were asked to complete dietary questionnaires every four years. At the end of the 10-year study period, some 2,718 women had developed type 2 diabetes. Once the researchers examined the women’s intake of plain water, fruit juice and sugar-sweetened beverages (SSBs), they found that, while the amount of plain water the women consumed on its own was not associated with type 2 diabetes risk, when participants swapped a cup of water for a cup of fruit juice in their diet, their risk of type 2 diabetes risk dropped by 8%. Interestingly, fruit juice fared no better than SSBs when it came to diabetes risk: Swapping plain water for SSBs was associated with a near-identical 7% risk reduction.
FRUIT JUICE AND WEIGHT
The potential link between fruit juice and weight gain has been a source of debate for years. As the theory goes, while we have a certain innate ability to control our caloric intake through food (even if we are not calorie counters), we don’t have the same ability when it comes to beverages. In other words, the more calories we drink, the more calories we tend to consume overall, and the more susceptible we are to weight gain. Not surprisingly, numerous studies have demonstrated that individuals who drink sugar-sweetened beverages such as pop, vitamin waters and fruit drinks (those are the ones that contain both fruit juice and added sugar) tend to consume more calories over the day, and are more likely to be overweight or obese.
On the other hand, when it comes to 100% fruit juice and weight gain, the link has been murky: First, there have been fewer studies conducted on the effects of replacing juice with water than there have been on SSBs, and second, while a handful of studies have demonstrated that juice drinkers tend to consume more calories overall, the research has not necessarily been able to link those extra calories with weight gain.
For example, a recent study published in the journal Nutrition Research found that children and teens who consumed an average of 10 oz (just over a cup) of 100% orange juice were no more likely to be overweight or obese than their non-juice-drinking counterparts, even though they consumed an extra 120 calories per day (since an 8 oz/250 mL/1 cup serving of orange juice provides about 120 calories, that suggests that almost all of the extra calories they consumed came from juice. This would seem to support the theory that we don’t compensate for calories from drinks). Notably, however, the juice drinkers also consumed more whole fruit, which could suggest their diets as a whole were healthier than their counterparts.
Similar results were found in a 2010 study, published in the Journal of the American College of Nutrition, which found that adults who consumed juice regularly were actually at a lower risk of obesity than their non-juice-drinking counterparts, though, once again, lifestyle factor may have played a role. In other words, juice drinkers might have healthier diets and lifestyles overall, which, in turn, might help them to prevent unwanted weight gain.
THE BOTTOM LINE
So what to make of all of this seemingly conflicting data? No one can yet say for sure, but it’s generally agreed that, if you are going to drink juice yourself, or serve it to your children, keep portions moderate: a cup (or less) per day for adults, and a half-cup (or less) per day for kids is reasonable for most. (Note that athletes, very active individuals, and those who for various reasons have a hard time meeting their energy needs, may benefit from a higher intake.) On the other hand, if you don’t drink juice already, I wouldn’t go out of my way to start; plain water is almost always your best choice. And always remember, when given the choice, you’re better off eating a whole piece of fruit than drinking juice: You simply can’t replace the nutrients and sense of fullness that are lost when fruit is turned into juice.
Jennifer Sygo is a registered dietitian at Cleveland Clinic Canada (clevelandclinic.ca), which offers prevention and wellness counselling in Toronto.