The Fiftysomething Diet: Should You Be Juicing?
Experts ponder the pros and cons of drinking your fruits and vegetables
Maureen Callahan is a registered dietitian, recipe developer and lead author of the Health.com diet book review series.
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Juicing, which came into vogue in the early 1990s, usually refers to using extractors far more powerful than the blender in your pantry to "chew" or grind raw fruits and vegetables for the sole purpose of getting at their juice. Skin, seeds, and fibrous materials are discarded.
Why juice your produce instead of eating it?
The theory is that the unpasteurized, highly concentrated juice holds more nutrients, antioxidants and disease-fighting compounds than either bottled, pasteurized juices or the whole fruit or vegetable itself.
We know that eating lots of whole fruits and vegetables is good for our health. But despite the hype, there hasn't been a lot of definitive research showing how, or if, liquid fruits and veggies might confer the same benefits. Still, there are some things we have learned:
- Most of the beneficial nutrients, antioxidants and disease-fighting chemicals in whole produce are contained in their juices, which some people find more palatable than the produce itself. So if you wouldn't otherwise eat, say, kale, parsley or celery, drinking their juices nets you nutrients you wouldn't otherwise encounter.
- Juices may help ward off Alzheimer's. A 2006 Vanderbilt University study found that people who consumed three or more servings of fruit and vegetable juices each week (bottled or extracted) appeared to be 76 percent less likely to develop signs of Alzheimer's over 10 years than those who drank fewer than one serving a week. Dr. Qi Dai, the Vanderbilt associate professor of medicine who directed the study, credited the benefit to polyphenols, a type of antioxidant plentiful in the skins and peels of certain fruits and vegetables. "Animal studies and cell culture studies confirmed that some polyphenols from juices showed stronger neuroprotective effect than antioxidant vitamins," Dai said, though he added it was unclear which juice or combination of juices delivered the strongest benefit.
- Celery juice may lower your blood pressure. A 20-year animal study found that 3-n-butyl phthalide, an extract found in celery, lowers blood pressure and cholesterol levels. Researchers at the University of Chicago Medical Center reported that the compound appeared to relax the muscles that line blood vessels. The daily dose needed to gain this benefit appeared to be about four stalks, which explains why one might want to get it through juice. (You can find some popular healthy juice recipes here.)
(MORE: Follow These Guidelines for Healthy Eating)
The list of potential downsides to juicing is at least as compelling as the benefits:
- You may not get enough fiber. Juicing leaves behind most of the skin and pulp of fruits and vegetables, so devotees can miss out on the health benefits of fiber, which is in short supply in most of our diets already. Juicing proponents suggest that removing the fiber helps the body access nutrients more easily, but experts at the Mayo Clinic and elsewhere say that's not true. Your body needs fiber to promote healthy digestive function and fiber helps fill you up better than juice alone.
- Regularly juicing high-glycemic fruits, like pineapple or watermelon, especially in combination with a low-fiber diet, could cause a spike in blood sugar and raise your risk for diabetes. Similarly, "juice fasts" lasting several days will not eliminate toxins from your body and could be dangerous for diabetics since a steady flow of juices releases carbs and sugars into the body without the buffer of other foods. As a better strategy, juice mostly vegetables, adding a small amount of fruit for sweetness and continue to eat a healthy, balanced diet of whole foods.
- Juices aren't necessarily the answer to weight loss. In fact, homemade juices from some fruits and vegetables can contain more natural sugar than you might realize, adding a surprisingly high number of calories and thwarting efforts to drop pounds. To complicate matters further, because juices tend to lack fiber, they may not be filling, potentially leaving your hunger unsatisfied.
- Juices aren't miracle cancer fighters. "There is no convincing scientific evidence that extracted juices are healthier than whole foods," according to the American Cancer Society. "Available scientific evidence does not support claims that the enzymes from raw foods have special, health-giving properties since they are broken down during digestion anyway."
- Fresh-squeezed juices spoil easily because they are unpasteurized, bringing a risk of contamination. If you're juicing, avoid this risk by drinking juices the same day they're extracted or freezing the excess in ice cube trays you can thaw out at a later date.
- Juicing can be expensive. It takes a fairly high volume of produce to make a small volume of juice and extractors can cost from about $30 to more than $300. (If you're in the market, Consumer Reports has reviewed the top models.)
(MORE: Fiftysomething Diet: Healthy Food Swaps)
The Bottom Line
Freshly extracted juices from all types of produce can be a beneficial part of a healthy diet in moderate amounts. But juices are not fundamentally healthier than whole fruits or vegetables and they are neither longevity elixirs or miracle treatments for what ails you.
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