Wednesday, April 29, 2009

Dietary Guidelines Advisory Committee meeting

Briefly live-blogging a portion of the webcast of the third meeting of the 2010 Dietary Guidelines Advisory Committee (agenda .pdf).

Presentation by Adam Drewnowski, University of Washington: "There are people who cannot afford many of the foods that are being recommended." Still, for the most part, he doesn't overstate the case that economics drives nutrition problems, noting that there are healthy affordable foods (once one gets above the most desperate minimal budget levels). Committee member Lawrence Appel asks a skeptical question about whether people would really eat much differently if healthy food were free. Drewnowski: "Energy dense foods do taste good. I admit that. Yes, they do."

Presentation by Frank Sacks, Harvard School of Public Health. Says blood pressure benefits are accentuated at particularly low sodium levels. This contrasts with the Salt Institute's input to the committee, arguing that only a fraction of people benefit from salt reduction, and that low-salt diets may have harmful side effects. Reacting to an argument that young and middle-aged people needn't limit salt, because their blood pressure is less responsive to sodium intake, Sacks notes dryly: hopefully, if they survive, the 45 year olds will live to become older.

Sacks also summarizes a growing body of research suggesting that patterns of weight loss and regain over time are similar across weight-loss diet strategies (Ornish, Atkins, Weight Watchers, etc.). Although the Dietary Guidelines have traditionally reflected a reductionist approach, emphasizing nutrient recommendations, Sacks doesn't shy away from the implications of his summary. In response to a question about whether the old Dietary Guidelines recommended range for fat calories is still correct, Sacks takes a line that one might equally have heard from Michael Pollan: perhaps we don't even need a recommended macronutrient range for fat. "Recommendations should be based on food."

Presentation by Patricia Crawford, University of California. In the same vein: "People want food-based specifics for the translation of nutrient guidelines."


Janet said...

Interesting. Thanks for the coverage. I wonder if anyone ever tested how people would eat if beans (as one example) got the marketing attention that junk food gets. Alas, too many of us seem to be slaves to ads.

Anonymous said...

Good report; I'd like to add a couple substantive observations beyond the concern that by barring public attendance at the meeting, the Committee seems to be running directly counter to the rhetorical emphasis of the Administration that greater transparency be encouraged.

I thought that a key point in Adam Drennowski's presentation was his statement: “It is possible to improve dietary quality if we help the public identify foods within each food group that are nutrient dense, affordable, accessible, and appealing. Limiting low-cost foods may not help diet quality or reduce obesity rates. We need a positive approach to dietary guidance.” A nutrient-dense diet is a "quality diet" like the DASH Diet that we at the Salt Institute have been promoting for 12 years.

Frank Sacks continues his efforts to try to limit the salt recommendations to blood pressure. The real question is: would reducing salt intakes improve health. Blood pressure is one risk factor. Others are insulin resistance, plasma renin activity, aldosterone production, etc. -- all of which increase risk with salt reduction. I suppose your statement that we think "only a fraction of people benefit from salt reduction." Perhaps. We really don't know. What we do know is that hypertensives on low salt diets don't benefit (and may even have more heart attacks) nor do congestive heart failure patients. The CHF study is the first-ever randomized trial of the health outcomes of low-salt diets and CHF patients on low-salt diets fared far worse than those on normal diets. For Sacks to claim, as he did, that there is "no downside" to low-salt diets is just factually wrong.

Still, Sacks wants to talk only about BP and on that he drastically overstated his case when he claimed that salt reduction and the DASH Diet have "additive" benefits. The original DASH Study found the most sensitive group, hypertensives, achieved an 11.4 mmHg fall in systolic BP; the same group in the DASH-Sodium trial which also cut salt by 60% achieved an 11.5 mmHg fall. The difference is miniscule and, to us, proves the validity of the DASH Diet (see Drennowski above) and exposes Sacks as an advocate. That came home loud and clear when he responded to a question, beginning his response: "Personally...." That's the point, with double meaning. It IS personal for Sacks and it is also his personal opinion that he's advocacting, not the data.

And, thank you, Patricia Crawford, for your argument that people eat foods, not nutrients. We need food guidelines, hopefully positive messages as Dr. Drewnowski emhasized.

Dick Hanneman
President, Salt Institute

Yoni Freedhoff, MD said...

Thanks Parke for recounting the Sacks line regarding the Salt Institute's spin on why we don't need to reduce salt in the under 45s.

Gave me a good chuckle as does the lengthy Big Salt defense in the comments above mine (though I can't say I blame them for doing their job) when we're talking about a population consuming many thousands of milligrams of sodium beyond daily recommendations. Also gives me a chuckle to read the cherry picking of studies the Salt Institute chooses to discuss (go figure).

Warm regards,

usfoodpolicy said...

Cool comments. Have been thinking a lot in recent months about how healthy food can be appealing rather than austere.

On salt, the great comments from Hanneman and Yoni remind me to read more on this issue!

Dash diet said...

DASH diet has limitless health benefits. Its full form is Dietary Approaches to Stop Hypertension. It has many health benefits like it helps curbing damaging high levels of blood pressure, reduces cholesterol levels to name a few. The better a person sticks to the DASH diet, lesser will be the pace of mental down slide.