A global consensus on lifestyle as medicine.
I Like the Dietary Guidelines Report
The highly expert committee reviewed evidence on all sides and pushed aside personal interests. Can its critics say that?
David L. Katz, MD, MPH
health.usnews.com
|
February 23, 2015

I have neither eggs, nor eggplants to sell you. I am not peddling bread, or breadfruit. Nothing in my life will be directly affected whether you choose to eat mostly steak, or beefsteak tomatoes today; salami, or salmon, or spinach.

I like the dietary guidelines report very much, as someone with no food to peddle, but who tries to pedal hard uphill every day to advance the cause of public health. I like the report very, very much. I think it is excellent.

So, naturally, it is under assault from all directions. Some of the protest is discernibly well-intentioned. My vegan colleagues, for instance, don’t like the loosened guidelines for dietary cholesterol. They point out, correctly as best I can tell, that dietary cholesterol does, indeed, tend to raise blood cholesterol levels, and perhaps heart disease risk, against the backdrop of an optimized vegan diet.

But the Dietary Guidelines Advisory Committee is not trying to improve an optimized vegan diet, nor advising vegans to start eating eggs. They are, eponymously, advising the federal agencies that will issue dietary guidelines for all Americans, only a rounding error among whom are vegans, whether optimally so or otherwise. Against the backdrop of the prevailing American diet, they are quite correct on the basis of aggregated evidence that dietary cholesterol does not seem to warrant our targeted attention.

Somewhat less justifiably, the report is under immediate barrage from those who do have foods to sell you, concerned about those sales and attendant profits. Politico tells us that the meat industry is “sharpening its knives” to eviscerate recommendations for consuming less red meat and more plants. But, of course, these recommendations are exactly what the evidence for human health supports. They are what the evidence for planetary health and climate stabilization support as well.

For the most part, protests by those selling meat against recommendations to eat less meat are innocent for being transparently self-motivated. The only real potential for mischief here, and it’s not trivial, is the process of political lobbying. Before the Advisory Committee report sees daylight as actual dietary guidelines, it is turned over to federal agencies – the Department of Agriculture and the Department of Health and Human Services – and is subject to the tender mercies of politicization. Sharpened knives on open display may be the least of our worries.

Finally, though, there is a kind of attack that I consider deeply disturbing, because it is potentially disingenuous, and misleading into the bargain. Our culture doesn’t reliably differentiate actual expertisefrom an opinion asserted very loudly, which plays perfectly into the hands of fools and fanatics. Non-experts with strong opinions and books to sell are all too often treated like actual experts in our culture, given access, for example, to the rarefied real estate of our most venerated newspapers. That collusion makes the non-expert with something to sell look like an expert, and makes the newspaper look as if it has lent its imprimatur – as perhaps it has. But a strong opinion is not the same as actual expertise, and the fast track to a best-seller list involves citing only the evidence that supports that opinion, and ignoring all else. Caveat emptor.

The Dietary Guidelines Advisory Committee was permitted no such indulgence. This highly expert, multidisciplinary group had marching orders to generate the best, evidence-based dietary guidance they could. Conflicts of interest had to be disclosed, and expunged. The work had to take place in the transparency of a veritable fish bowl, with multiple opportunities for public commentary along the way, including now. The 572-page report includes hundreds and hundreds of scientific citations, including papers espousing both sides of any given argument – because the job of the committee was to examine all sides, and reach evidence-based consensus, not pave the way to a polarized position they already held before they started.

In other words, whether or not the work of this committee conforms to your personal preferences or preconceived notions, you can trust it as the honest, diligent work of scientists who don’t necessarily find it easy to agree with one another, working on behalf of public health. Whether or not you can trust those attacking it is in most cases highly suspect, and at a minimum I advise you to look for ulterior motives. They will generally not be hard to find.

As for the particulars of the report, I particularly like this passage:

The overall body of evidence examined by the 2015 DGAC identifies that a healthy dietary pattern is higher in vegetables, fruits, whole grains, low- or non-fat dairy, seafood, legumes, and nuts; moderate in alcohol (among adults); lower in red and processed meats; and low in sugar-sweetened foods and drinks and refined grains. Additional strong evidence shows that it is not necessary to eliminate food groups or conform to a single dietary pattern to achieve healthy dietary patterns. Rather, individuals can combine foods in a variety of flexible ways to achieve healthy dietary patterns, and these strategies should be tailored to meet the individual’s health needs, dietary preferences and cultural traditions. Current research also strongly demonstrates that regular physical activity promotes health and reduces chronic disease risk.

I appreciate this position both because it is just what the evidence supports, and because it eschews dogma, leaving people the latitude required to wind up loving the food that loves them back – as my own family does. There is no reason why eating cannot allow for both health, and pleasure.

As noted, the report’s emphasis on plant foods is based both on the body of evidence related to human health, and quite appropriately, on considerations of sustainability. Whatever the potential merits of a meaty, Paleo-style diet, they are substantially impractical as the prevailing norm for a huge population of humanity on a shrinking planet. The Dietary Guidelines for Americans serve an audience of over 300 million people, and that must be a consideration. A section in the advisory committee’s report devoted to sustainability is a very welcome addition.

There has been much debate lately about appropriate thresholds for dietary sodium. The committee concluded that most Americans still get more sodium than is good for us, and efforts to reduce prevailing intake should continue. Since roughly 80 percent of the sodium in the typical American diet comes from processed foods, rather than the family salt shaker, a shift to less processed, and morehome-prepared foods in general, rather than a fixation on sodium per se, is the right strategy. I agree entirely.

The committee resisted the clamor to renounce everything we thought we knew about saturated fat, and looked at the evidence on all sides of the argument. Despite the hype, no studies have shown health benefits of increasing saturated fat intake; they have, at best, indicated that when we replace an excess of saturated fat with an excess of sugar and refined starch, we are going sideways. In contrast, intervention trials with both Mediterranean and plant-based diets low in saturated fat have been shown to slash rates of heart disease. The committee, presumably on the basis of just such evidence, retained saturated fat as a nutrient of concern, suggesting we limit our consumption. Again, however, the right response is about foods, not nutrients. By eating principally wholesome foods in sensible combinations, saturated fat intake comes down. It comes down, as well, by eating low-fat junk foods, but that doesn’t mean it’s a good idea.

In contrast to the treatment of saturated fat, the committee did change course for dietary cholesterol as noted. This, too, was an evidence-based enterprise, and here, too, in my view, they got it right.

Unlike competing factions in our culture, the committee obviously felt no obligation to espouse dietary dogma. The recommendations rightly recognize the harms of excess sugar and refined starch, while also noting the liabilities of excessive intake of meat, processed meat especially. I searched the document, and found no mention of the word “gluten.”

Finally, the committee acknowledged the importance of family, although I would have liked that to be even greater. A cultural emphasis on families eating well together will speed the dawn of the day that “dieting” dies – and eating well together replaces it. In the world’s Blue Zones, they don’t diet – they live it, eating well in traditional patterns as families and communities. As a result, they live longer and better than the rest of us.

The job of the 2015 Dietary Guidelines Advisory Committee was to use the best available evidence, not the evidence they liked best, and generate reliable dietary guidance to advance public health. I think they did an outstanding job. I think they did just that.

And so it is that I, with neither beans nor bratwurst nor a diet book to sell you, say: bravo!

But as we have been told, knives are already being sharpened. More worrisome are the veiled attacks, masquerading as something else, fomenting in the shadows. For daring to tell the truth about carrots, the committee report will be forced to run a gauntlet of swinging sticks.

It deserves to survive that gauntlet. The committee members did their job, looking out for our well-being. Let’s return the favor now. Please stand with me in standing up for the Dietary Guidelines Advisory Committee report. It is honest, and it is evidence-based. It is predicated on epidemiology, not ideology.

I like it, and take this opportunity to say to the committee members who have worked very hard for long months: Thank you.

X