Blog | Friday, September 6, 2013

Fruit, fructose and frittering

Sophie Egan did an excellent job in the Well blog of the New York Times making the case for eating fruit. The question of course is why does anyone need to make a case for eating fruit? We have cited the combination of “fruits and vegetables” as the cornerstone of healthful eating throughout the entire era of modern nutrition, and it has been so since before the advent of modern humans. Homo erectus ate mostly plants, and their predecessors, the australopithecines and such, ate nothing but.

Why on earth, on the earth of gorillas, chimpanzees, Homo sapiens, 5-a-Day, and Produce for Better Health, is there any need to allocate the rarefied real estate of the New York Times to reaffirming what should be time-honored and self-evident?

Well, for one thing, there is the issue of fructose. The one minor criticism I have of Ms. Egan’s column is that she let Dr. Robert Lustig off easy. Dr. Lustig, as many of you likely know, is the man who made “fructose is toxic“ part of our new-age lexicon.

The only real problem with the “fructose is toxic” platform, other than all the ways it’s misleading and wrong, is that the one place fructose, per se, is found in our food, is fruit. Dr. Lustig is quick to point out, as he does in Ms. Egan’s column, that fruit is fine. But that’s one whopper of a proviso. Fructose is toxic, it seems, except for the one place you will actually encounter pure fructose.

Lustig’s real nemesis, of course, is high-fructose corn syrup. But that’s really just sugar. Table sugar is 50% fructose; high-fructose corn syrup is, at most, 55% fructose. They are all but the same thing, and are the same in all ways that really matter. We eat too much added sugar, but that message, I guess, lacked the sex appeal and conspiracy theory edge of “fructose is toxic.” But now we reap the fruit sown of that misguided seed: We have to tell people it’s okay to eat fruit.

In a world where masses of us rarely get much past headlines, you really don’t want your headline to require an immediate and massive proviso to be correct. Dr. Lustig may have thought “fructose is toxic, except the one place where you will actually encounter it in pure form, namely fruit” would fly; but the first bit, quite predictably, took off and left the boring clarification behind.

How do I know? As a frequent reviewer of health content for various online outlets, I have seen health professionals actually cite Dr. Lustig’s anti-fructose rants to justify their advice against eating fruit! Dr. Lustig renounces this, of course, but the distortion of his message is what set it in motion in the first place.

Dr. Lustig is only the latest flash in the pan where our goose is cooking; he certainly didn’t invent the over-simplified health message that cries out for provisos. We’ve been living and dying on the unintended consequences of such ill-conceived communication for decades. We’ve even been accumulating reasons to be confused about fruit.

First, of course, just as we were crawling out from under the huge pile of Snackwell cookie crumbs that piled up during our low-fat boondoggle, we got the epiphany that “carbs” were the enemy now. That, of course, required the proviso we never got, that everything from lentils to lollipops is a source of “carbs,” but scarcely created equal. During the peak of the Atkins’ diet craze, I actually heard a radio DJ talking about systematically removing the beans from her chili because, after all, they contained carbs!

The low-carb message also drove people away from fruit. Unlike Lustig, who is busy telling people it’s not what he meant to say, Atkins and the low-carb apostles actually told us all to avoid fruit. There was never a shred of evidence to support this, of course, but “just cut carbs” sure is catchy.

And then, needing a new way to misdirect the masses because there were books to sell, we moved on to the low-glycemic refinement of the just-cut-carbs message.

The value of low-glycemic eating is, in my view, very well established. But the likes of Dr. David Jenkins, who invented the glycemic index, and Dr. David Ludwig, among those prominent in the study of it, have not advised against eating fruit. But the pop-culture contortions of the message led in exactly that direction. Among them was a book called The GI Diet, representative of the breed, which warned people away not only from fruit, but from high-glycemic-index vegetables, such as carrots. My reaction was, and remains: You find me the person who can legitimately blame their obesity or diabetes on apples or carrots, and I will give up my day job and become a hula dancer!

It’s been quite a few years, and there’s still no grass skirt in my closet.

Of course fruit is good for us! Maybe it’s not as good for us as vegetables, and maybe we should have been saying “vegetables and fruits” rather than “fruits and vegetables” all along. But fruit is good for us. Overwhelmingly, diets and health in the U.S. stand to improve with the addition of more fresh fruits, and the foods the fruits displace. After all, if you have an apple or banana as a snack, you not only benefit from the apple or banana; you benefit from the avoidance of the chips or cheese puffs you might have eaten instead.

Telling people fructose is toxic except when it’s in fruit, or carbs are the enemy unless they are in lentils, is a bit like telling people that calories are poisonous (since an excess of them is driving the obesity epidemic) except when found in plain and wholesome food, necessary for survival. Well, then, maybe that first message was just plain wrong! We have decades of experience to teach us that messages needing immediate corrective caveats cultivate nothing but confusion, and forestall the objectives of public health.

So here we are, long after it should no longer be necessary, telling people, in the New York Times, no less, that fruit is good for them.

Why do I care? Because we are frittering away our social capital. We are frittering away our capacity to inform and empower. The more silly messages we propagate and retract, the less people take any of us “nutrition experts” seriously. And the more time we spend frittering, such as telling people that what everyone long thought they already knew is actually still true, the less time we are allocating to putting what we know to any constructive use.

Frittering, in other words, is toxic; no proviso required.

David L. Katz, MD, FACP, MPH, FACPM, is an internationally renowned authority on nutrition, weight management, and the prevention of chronic disease, and an internationally recognized leader in integrative medicine and patient-centered care. He is a board certified specialist in both Internal Medicine, and Preventive Medicine/Public Health, and Associate Professor (adjunct) in Public Health Practice at the Yale University School of Medicine. He is the Director and founder (1998) of Yale University's Prevention Research Center; Director and founder of the Integrative Medicine Center at Griffin Hospital (2000) in Derby, Conn.; founder and president of the non-profit Turn the Tide Foundation; and formerly the Director of Medical Studies in Public Health at the Yale School of Medicine for eight years. This post originally appeared on his blog at The Huffington Post.