The Case Against Juice Is Stronger Than Ever

Juice is the health trend that just won’t go away. There’s a juicing shop on practically every city block, and everyone from your Spin instructor to your mother downs glasses of it daily. There’s no doubt that juicing is ubiquitous—but is it as healthy as everyone says?

Juice can help you consume more vitamins and minerals, and that’s a positive for people who struggle to eat enough fruits and vegetables. But experts say it may not deserve its health halo. In a paper published last winter in the Journal of the American College of Cardiology, experts scrutinized several nutrition-hyped foods—including juice—and wrote that “whole food consumption is preferred” over a liquid diet.

Here’s what to know before you sip.

Juice is missing an important component

While juice does contain the vitamins and minerals you’d find in fresh produce, it’s devoid of the vast majority of dietary fiber—the parts of the plant your body can’t digest. Just because your body doesn’t absorb fiber, however, that doesn’t mean it doesn’t use it.

Fiber moves through your gastrointestinal tract to help regulate healthy digestion and keep you full longer, according to the Mayo Clinic. Eating a high-fiber diet has also been shown to reduce your risk of diabetes, heart disease and obesity.

And without the missing fiber, juice won’t keep you full. Research has found that drinking nutrients is less satisfying than eating them. “While your body likes the vitamins, minerals and antioxidants [in juice], juices lack fiber and don’t require chewing, so they’re less satiating than whole produce,” explains New York City-based dietitian Cynthia Sass.

Most juice is pure sugar

Most produce naturally contains sugar, and fruit typically packs more than vegetables. Without fiber in the mix, juice is essentially just the natural sugars and water found in its ingredients, says Scott Kahan, the director of the National Center for Weight and Wellness in Washington, D.C. Though natural sugar may seem harmless, your body does little to distinguish between the sugars in an apple versus those in a piece of candy, Kahan says.

“Whether the sugar comes from a fruit or a vegetable or whether it’s added sugar is probably less of an issue as compared to what goes along with the sugar,” Kahan says. In other words, when you eat a banana, the fiber in the fruit helps to slow the absorption of its sugars into the bloodstream, preventing spikes in blood glucose. When you drink juice, on the other hand, the sugar hit is immediate and unmitigated, leading to insulin spikes and eventual crashes. In the short-term, this means your energy levels are likely to seesaw; in the long-term, insulin spikes may contribute to weight gain, type 2 diabetes and other issues.

Plus, Sass says, it’s much easier to overdo it on sugar when you’re drinking juice versus eating solid food. “A 16-ounce juice made primarily from fruit could be the equivalent of eating several cups of fruit at once, something most people would never do,” she says. “In addition, because they’re more concentrated, juices provide more carbs in the form of sugar than most people can burn or use in one sitting.”

Opting for green juice—that is, a juice made entirely or primarily from vegetables—is a smarter choice, Kahan says, because vegetables are typically lower in sugar and calories than fruits.

Juice cleanses probably won’t help you lose weight

“I have never in my career seen a reputable scientific study showing that juicing and cleansing has any effect on weight loss or other positive outcomes,” Kahan says. While a juice cleanse may help you drop pounds in the short-term, Kahan says there’s no data to suggest that they help burn fat or lead to sustained weight loss over time. It’s actually fiber—the stuff juice leaves behind—that may help you lose weight, Kahan says, because it helps you stay full longer and avoid overeating. “Fiber, from any source, is known to cause more satiety and leads to at least a little bit of weight loss, so keeping the fiber in is a smart way to go,” he says.

Weight loss aside, juice cleanses are often just plain unhealthy, Sass says. “I’m not a fan of juice fasts or cleanses because they tend to lack important nutrients, including fiber, protein and healthy fats.”

Juice may even make you gain weight

When your body gets a hit of sugar, it expects calories and substance to go along with it. When you drink a sugary juice without consuming any fiber to keep you satisfied, your body can get confused and hungry—potentially leading you to overeat later on. Kahan says studies have shown that consuming solid foods, as opposed to liquids, may offer more satiety, leading people to eat less afterward.

Smoothies may be better for you than juices

Smoothies are by no means a perfect food. It’s easy to overdo it on fruit or to get tricked into eating sugary add-ons like sorbet, Sass says—but since they typically use whole fruits or vegetables, they at least keep fiber in the equation. “I’m a fan of smoothies made with reasonable portions of whole vegetables and fruit, combined with a healthy protein, like plant-based protein powder, and wholesome fat, such as avocado or almond butter,” Sass says.

The bottom line

Juice may not be the health hero it’s made out to be. If you love it, though, it can be part of a balanced diet. Just keep portions moderate, incorporate plenty of low-sugar vegetables in your blend and have some fiber-rich foods in or with your beverage.

Perhaps most importantly, avoid the common trap of thinking of juice as a zero-calorie freebie, Kahan says. “People end up drinking as much of it as they would like and don’t realize how it can really add up in sugar and calories,” he says. “It’s a snack. It’s not free food.”