Weigh Your Options With Juiced Up Smoothies

Smoothies are everywhere—at the mall, at the gym, even in your local supermarket. But when it comes to picking the right smoothie, dieticians advise, "Buyer beware."

The trend New Orleans bartenders started decades ago with their exotic blends of fruity alcoholic drinks has turned into a $340 million industry fueled by more health-conscious aficionados. Today’s smoothies are non-alcoholic—made up of fruit, dairy and a variety of other ingredients to create healthy smoother-than-milkshakes that double as drinkable meals. Body-builders get a workout boost by downing smoothies with protein powder and amino acids. New moms enjoy extra servings of calcium in yogurt-based smoothies. Cancer patients mix medicines and proteins in their smoothies.

"A smoothie is a really convenient way to get fruit in," says registered dietician Nadine Pazder, who recommends a simple breakfast smoothie recipe for those who might otherwise skip a morning meal. "It’s easy to get some dairy and protein and fruits in there, but there’s a big caution because they are not low calorie."

Because smoothie lovers tend to use the drinks as meal replacements, they often add powdered vitamins, minerals and herbs in an effort to increase the smoothie’s nutritional value. Some smoothie retailers even provide supplement pills for customers to buy a la carte.

When Additives are Not So Smooth

"I would be really cautious about the kind of additives that are being put into a smoothie," Pazder says. "Fruits in themselves have a lot of antioxidant benefits. To add additional vitamins is not necessary, and in some cases, may not even be safe."

Adding vitamins to commercial smoothies does not make up for the natural nutritional imbalance of the liquid meal, agrees registered dietician Carol Koprowski, Ph.D., who coordinates the University of Southern California’s master’s in preventive nutrition program.

Koprowski warns that adding megadoses of vitamins to smoothies, especially those that run through the body quickly, can be harmful, especially if consumers are already taking multivitamin supplements and other fortified foods like cereals and juices. "With high doses of water-soluble vitamins, what you end up with is very expensive urine," Koprowski says. "Evaluate dietary supplements the same way you would medication—just because they are natural, don’t assume they are safe, especially at higher doses."

Pazder adds that it’s important to be sure that any vitamins, minerals or herbs you add to your smoothie don’t interact with any prescription or over-the-counter medications you’re taking. For example, adding ginseng to a smoothie for an energy boost may increase the effect of estrogen for those on hormone therapy, or interact negatively with the heart medicine digoxin. Ginseng can also cause headache and manic episodes for people on MAO inhibitors like Nardil.

There are other dangerous interactions to be aware of: Always check with your doctor or pharmacist before adding to your smoothie.

Benefits to 'Juiced Up' Smoothies

Still, registered dietician Lisa Nicholson boasts the positive side to smoothie additives. Since many vitamins and minerals are better absorbed when taken with a meal, "juiced up" smoothies can be beneficial to those who don’t over-supplement in the rest of their diets. With the wide range of additives available, it’s possible to pick and choose the combination that best fits personal dietary needs.

Common additives and their benefits include:

• Wheat germ oil for energy:
  Putting wheat germ oil in a smoothie adds protein and unsaturated fatty acids, along with minerals, B-Complex vitamins, Vitamin E and iron.
  
  
• Vitamin C for enhanced immune function:
  This antioxidant vitamin, which can be found in many fortified foods, is important for immune function, but dieticians caution that megadoses are not mega-effective and may even cause harm. Recommended dosages of Vitamin C can help the body absorb calcium, iron and folic acid and promote the formation of collagen.
  
  
• Yeast for energy and nutrients:
  Yeast additives increase smoothies’ protein content, and add B-Complex vitamins and minerals, including iron.
  
  
• Spirulina for energy and appetite control:
  Blue-green algae, a complete protein, are high in chlorophyll (which can freshen your breath), as well as B-Complex vitamins and minerals. It is purported to help stabilize blood sugar levels and thereby help control appetites.
  
  
• Creatine for energy and muscle building:
  This combination of amino acids, popular among body-builders, can increase muscle bulk as well as heighten energy levels. Following creatine dosage guidelines is essential—its abuse can lead to liver and kidney damage.

Nicholson tells smoothie buyers to check ingredients diligently to find out if they are getting real fruit and dairy, not artificial sweeteners and empty preservatives or flavors.

Most important, she says, is that your smoothies are part of a balanced approach to your diet, whether you enhance them with additives or not.