Juicing became popular in the early 1990s and seemed the penultimate healthful dietary activity. (In the spirit of full disclosure, I am drinking my usual morning smoothie and I have a juicer in my pantry.)
These clever devices turn fruit and vegetables into juice, and may be as simple as a cone in a shallow bowl that you crush half an orange against to produce juice. Mine is electric, the cone spins. You can get even fancier ones – some people actually purchase a commercial juicer that processes large quantities of fruit quickly, and looks industrial and complicated.
To those who love it, juicing is such an obviously healthful activity that to discuss the science behind it seems almost heretical. Juicing enthusiasts discuss the amazing freshness and flavor that come from its organic source, and will give you a list of vitamins, minerals and magic that it provides. They believe it is more than food. It is an elixir, or even a medication.
The science, however, is less optimistic, if not somewhat discouraging. Consumption of fruit juice is associated with an increased risk of Type 2 diabetes, but eating that same fruit reduces the diabetes risk. Eating apples reduces cholesterol, but apple juice doesn’t. Drinking juiced fruit in childhood is associated with increased obesity, and eating the same fruit is not.
Faint praise, indeed.
The fiber in fruit contains polyphenols, which are antioxidant, free radical-scavenging, cancer-fighting chemicals. These are lost during juicing when the pulp is discarded. After you take out the fiber, you have sugar water with high levels of certain vitamins. Surprisingly, adding back the pulp does not equal the value of the whole fruit. The research that juice + pulp does not equal whole fruit is probably meaningful only in commercial operations, not in your kitchen.
Let’s zero in on wheat grass.
Wheat grass is young wheat that looks like it belongs on a fairway. At this stage there is no gluten in wheat grass. It is juiced and consumed by countless people, who are probably holding their nose and feeling a little cow-like. That would be a sacred cow, as wheat grass is consumed by true believers. Something that looks and tastes this bad has to be good for you. Surprisingly, there is no good evidence of disease prevention based on regular consumption of wheat grass juice.
When it comes to eating whole fruits and vegetables versus juicing, the whole fruit is clearly superior in nutritional value. Now compare juicing to almost any other thing you might eat or drink: a slice of pizza, a cheeseburger and a soft drink, etc. Many of these have vast amounts of unhealthful fat and calories.
Donald Bucklin, MD (Dr. B) is a Regional Medical Director for U.S. HealthWorks and has been practicing clinical occupational medicine for more than 25 years. Dr. B. works in our Scottsdale, Arizona clinic.