Juice

My workplace cafeteria recently opened a juice/smoothie bar, replete with nutricentric literature about "organic", "superfoods" and antioxidants. I like a good smoothie like anyone else, but on my first visit, I ordered my version of a vampiro - a mixture of beet and carrot juices I discovered in the popular La Guadalupana restaurant in Houston. All would have been well as the server handed me the glass but he was intercepted by the manager.

"Did you know that you would have to eat a whole bushel of carrots to get the nutrition in that one glass of juice?"

And he continued to regale me with all sorts of pseudoscientific drivel - about how discarding the fiber makes the nutrients vastly more available to the body, and how it helps to lose weight. I stared at him perplexed - how could this establishment peddle such informational nonsense when it is frequented by prominent biomedical research scientists?

Living in the first world, with the array of inexpensive and readily available foodstuffs, achieving significant malnutrition requires a concentrated effort. For the most part, many of the "nutritionism" advice and testimonials derive from post hoc ergo propter hoc fallacies, assigning instances of reported feeling better after consuming some item directly to that item. But this is not evidence, though taken as such. It isn't rigorously replicated or studied, yet somehow, people lend greater credence to it.

Something that does work, that improves health, is calorie restriction (CR) - or, in simple layman's terms, eating less. Not substituting more protein for carbs, not indulging in the latest superfood fad, simply cutting down the amount of food. In the original studies, animals that are fed less lived longer. Or so we thought. A recently published replication of the CR studies in monkeys did not replicate this original longevity result; this, thus, demonstrates the value of replication in scientific studies.

But what did come out consistently is that CR results in all around healthier animals, by most any measure other than longevity.

In then end, it's the simple reduction of food that may be behind the health benefits from "cleanses" or "juicing diets - but that knowledge won't help sell juicing machines, books, or videos.