Ask any nutritionist for some tips on a healthful diet, and the first or second thing out of her mouth will be "Eat more fruits and vegetables." Beverage manufacturers know that to consumers, fruit connotes health, which is why there are shelves and shelves of fruity drinks in your grocery store, deli, and even gym. But as Consumer Reports writes in its May issue, the word fruit can be awfully misleading. The magazine goes through what you're likely to see on the label of fruit drinks, and some of it may be surprising: A fruit "cocktail" drink, for example, might contain as little as 5 percent juice (with the other 95 percent from water, added flavorings, and sweeteners).
The Center for Science in the Public Interest published its own guide (.pdf) to health claims on fruit juice labels earlier this year, scrutinizing terms like "light," "antioxidants," and "omega-3s." What the CSPI mentions, and what many people don't know, is that even though it contains the important nutrients that diluted fruit drinks don't have, 100 percent juice has its downsides. The most obvious: Because it contains so much sugar, it's caloric. People who are looking to maintain or lose weight should really be drinking only two 4-ounce glasses a day, says Julie Miller Jones, a professor of family, consumer, and nutritional sciences at the College of St. Catherine in St. Paul, Minn. (I'd recommend you stop right now, go to the kitchen, and get out a liquid measuring cup to see what 4 ounces looks like. It's not much at all.)
Then there's the issue of what kind of sugar is in fruit juice. It's not that there are more calories in one sugar than another (all have 4 per gram). But there is some evidence that in the short term, large amounts of fructose can raise the levels of triglycerides in the blood, says Karen Teff, director of translational research at the Institute for Diabetes, Obesity and Metabolism at the University of Pennsylvania School of Medicine. "What we don't really know yet is what percentage of fructose within a drink results in the elevation of triglycerides," Teff says. There's much ado now about high-fructose corn syrup and its role in the American diet, especially soft drinks. HFCS, as people call it, is 45 percent glucose and 55 percent fructose. Many fruit juices, like apple, pear, and agave, have an even higher percentage of fructose, says Jones. Sucrose, or table sugar, is evenly split: 50 percent each of fructose and glucose. Glucose alone doesn't have the same effect on triglycerides, Teff says. She notes that there hasn't yet been a long-term study published showing how long such an effect would persist.
Jones says she's not too worried about the effect of fructose on blood triglycerides except in those people who are eating massive quantities of it (and thus are already overweight or obese). For the rest of us, the detrimental effect of excess sugar calories in general is what concerns her.
But there's a very easy solution: Eat whole fruit instead of drinking juice. That way, you get your vitamins and other nutrients plus a large dose of fiber, which slows the absorption of fructose by your liver. "When God made the poison, he packaged it with the antidote," says Robert Lustig, director of the Weight Assessment for Teen and Child Health Clinic at the University of California-San Francisco Children's Hospital. The other way to mitigate any harmful effects of fructose (and, for that matter, any other sugar delivering excess calories): Exercise.
Kids are the single biggest group of fruit juice drinkers, according to the American Academy of Pediatrics. Given the increase in childhood obesity, it's especially important to introduce your kids to fruit. If they want juice, keep tabs on their consumption. Diluting it with club soda or tap water can quench their thirst while getting them used to a taste less intensely sweet.