If you follow my Skeptoid podcast at all, you probably know that my all-time leading episode, by number of comments posted to the web site, is the one about MonaVie. It was actually about “superfruit” juices in general, but MonaVie distributors are the ones who have been pounding the site like a horde of Mongols and posting their comments. I graciously call it “posting comments”, it’s really more like harling. Harling, for those perhaps unfamiliar with the term, is the process of refinishing the walls of a Scottish castle by harling, or throwing, a handful of plastery weatherproofing (called harl) at the wall. Manure was a prominent ingredient in some harl. So I like to describe what the MonaVie distributors do as “harling” their comments at my site.

And, for some reason, I’m still constantly amazed at how many people in my neighborhood buy into MonaVie, both literally and figuratively. Without exception they parrot what they’ve been told; that it gives them more energy, it prevents illness, and generally promotes better health. How does it do this? If pressed for an explanation, they best they can come up with is that the açai from which it’s made (in part) is high in antioxidants and/or vitamins. Thus MonaVie’s comically high price is justified (a variety of similar juices are available in supermarkets at about a tenth the price, just without the fancy wine bottle and high school dropout pyramid business model).

This health claim is, as the saying goes, “so wrong it’s not even wrong”. At every level, this logic fails. It is based on the following assumptions:

MonaVie is high in antioxidants. Antioxidant supplementation has beneficial effects. We are all suffering from some antioxidant and/or vitamin deficiency.

1. We know that açai juice is not especially high in antioxidants (see this study by Australia’s consumer publication Choice). Eating an apple gives you more antioxidants than drinking a serving of any popular açai juice. And açai is only one of MonaVie’s 19 fruit concentrates (the rest of its ingredients are sweeteners and preservatives, like most similar fruit juices).

2. We know that antioxidant supplementation has, so far, not been shown to have any health benefits (see this analysis of current research by Dr. Stephen Barrett of Quackwatch). The oxidation of molecules is an important metabolic process. It makes no sense to try to attack it with antioxidants, just because you heard “they prevent aging” or some such nonsense.

3. We know that vitamin supplementation has no plausible value for people not suffering from a deficiency. With few exceptions, almost nobody who eats most of their meals in an industrialized country is likely to have a vitamin deficiency. And if you did, you’d be symptomatic, you’d know it, and it would show up on a blood test. If that’s not the case (which it’s probably not for anyone wealthy enough to own a computer on which to read this), your body already has all the vitamins it requires, and your regular diet already delivers more than your body uses. It’s like a car with a full tank. Overfilling the gas tank, so that it spills on the ground, is not going to give your car superpowers or super speed or super endurance or “more energy”. More vitamins than your body needs constitute just one thing: Waste. Your car’s gas tank can’t be fuller than full, and your body can’t be healthier than healthy. You either have an illness, or you don’t: You can’t have a super duper lack of illness.

Sometimes when a friend boastfully tells me that he had his MonaVie shot this morning, I’ll react with mock horror and say “Oh my gosh!! How terrible; what did your blood test show?”

Nothing? What did he think he was treating? Health?