20 August 2010

JAMA: Dietary Guidelines in the 21st Century - a Time for Food

The Journal of the American Medical Association (JAMA) has a commentary in the August 11 edition entitled: "Dietary Guidelines in the 21st Century - a Time for Food" by Darius Mozaffarian, MD, DrPH and David S. Ludwig, MD, PhD.

The purpose of this post is to summarize and review the article and to talk about whether it is consistent with the e4e dietary recommendations. Special thanks to Ashley at itsofinterest.com for providing me with a copy of the article.

Commentary Overview

The second part of the title is a great start. A time for food. The article itself is in three parts, I will summarize the parts below.

Section 1 - Introduction
In the introduction in the commentary, they talk about how the last 200 years have been characterized by the discovery of finer and finer detail of the nutrients and nutrient deficiencies that led to widespread disease. This has led to a reductionist perspective in our food choices.

Section 2 - Dietary Guidelines in the Age of Chronic Disease

This reductionist view led to guidelines in the 70s and 80s around minimum and maximum intakes of nutrients. Although appealing, the RDAs have not worked, perhaps simply because of the complexity involved in translating these recommendations into real dietary choices. I will copy the last paragraph of this section directly with some highlights of my own. It is an amazing admission.

"Nutritional science has advanced rapidly, and the evi-
dence now demonstrates the major limitations of nutrient-
based metrics for prevention of chronic disease. The propor-
tion of total energy from fat appears largely unrelated to risk
of cardiovascular disease, cancer, diabetes, or obesity. Satu-
rated fat—targeted by nearly all nutrition-related profes-
sional organizations and governmental agencies—has little re-
lation to heart disease within most prevailing dietary patterns.
Typical recommendations to consume at least half of total
energy as carbohydrate, a nutrient for which humans have no
absolute requirement, conflate foods with widely divergent
physiologic effects (eg, brown rice, white bread, apples). Foods
are grouped based on protein content (chicken, fish, beans,
nuts) despite demonstrably different health effects. With few
exceptions (eg, omega-3 fats, trans fat, salt), individual com-
pounds in isolation have small effects on chronic diseases.8
Thus, little of the information found on food labels’ “nutri-
tion facts” panels provides useful guidance for selecting
healthier foods to prevent chronic disease."

All I can say is WOW.
To sum up:
Fat ingestion, in general, is fine.
Saturated Fat is not bad.
Carbohydrate food sources are not necessary and are not created equal.
Protein food sources are not created equal.
Individual compounds in isolation are largely unimportant.
Food labels suck.

The only thing that I wildly disagree with in this paragraph is that they included salt as a compound as an exception to the compounds in isolation comment. Salt is nowhere close to the villain that people make it out to be.

Section 3 - The Need for a New Approach

This is the longest section, and I would have broken it into at least two parts, but I digress.

They start this section by citing associations between food classes and disease from a paper called "Dietary Patterns and risk of mortality from cardiovascular disease, cancer, and all causes in a prospective cohort of women", by Heideman, Schulze, Franco, et al.

They go on to say that the effects of foods "likely reflect complex, synergistic contributions from
and interactions among food structure, preparation methods, fatty acid profile, carbohydrate quality (e.g, glycemic index, fiber content), protein type, micronutrients, and phytochemicals." So far so good.

Then they say that "Healthy eating patterns share many characteristics, emphasizing whole or minimally processed foods and vegetable oils, with few highly processed foods or sugary beverages. Such diets are also naturally lower in salt, trans fat, saturated fat, refined carbohydrates, and added sugars; are higher in unsaturated fats, fiber, antioxidants, minerals, and phytochemicals; and are more satiating." This is mostly ok, but they are somewhat contradicting their earlier statement that saturated fat is ok. They're still missing the boat on salt, and unsaturated fats are a mixed bag. Unsaturated fat is not by itself good or bad. The devil is in the details.

They continue by saying that the nutrient based approach to diet has fostered products that replace fat with refined carbohydrate, "providing an aura of healthiness but without
actual health benefits." A national obesity prevention program categorizes whole-milk yogurt and cheese with french fries and donuts as foods together (eat only occasionally). Puts sauteed vegetables  and canned tuna in the same category as pretzels and processed cheese spread (eat sometimes).  Puts trimmed beef and vegetables and fat free mayonnaise as foods to eat almost anytime. They fortify processed food parts with vitamins and call them healthy.

Recently, there has been movement towards recommending food rather than simply nutrients. Nutrients are still important, we should not simply throw away the last several decades. Although this is a promising direction, they believe that much research work still remains to be done.

They finish with the following:

"The relatively recent focus on nutrients parallels an increas-
ing discrepancy between theory and practice: the greater the
focus on nutrients, the less healthful foods have become. As
national and international organizations update dietary guide-
lines, nutrient targets should largely be replaced by food-based
targets. Such change would facilitate translation to the pub-
lic, correspond with scientific advances in chronic disease pre-
vention, mitigate industry manipulation, and remedy wide-
spread misperceptions about what constitutes healthful diets.

"Although this approach may seem radical, it actually rep-
resents a return to more traditional, time-tested ways of eat-
ing. Healthier food-based dietary patterns have existed for
generations among some populations. Modern nutritional
science now provides substantial evidence for how foods and
food-based patterns affect health, guiding the design of more
effective approaches for the prevention of chronic disease."

e4e Take On This

Wow. This is great. It is generally consistent with the e4e recommendations in, "Eat Food, Light on Carbs, Mindfully." I talk about some general targets for macronutrients, depending on goals, but interestingly once you go light on carbs and stick to the fringes of your grocery store (food), it's hard to go too far wrong.

Regarding my comments on salt, please read the article "The (Political) Science of Salt" by Gary Taubes.

The 2010 food pyramid looks like it will be more of the same old stuff. This commentary represents a significant step towards dietary sanity in a mainstream medical journal. Is sanity finally winning?


  1. Thanks, this is very interesting. I agree it's a step in the right direction.

    I just saw a commercial tonight talking about some product with no saturated fat.
    Unfortunately, if you inundate people with false messages, they eventually learn the lie and doubt the truth. Maybe some news will report on this article at least.


  2. "They learn the lie and doubt the truth" - exactly! Tho some other rays of truth have broken thru:

    SPEECHLESS (Weston A. Price org.)

    What has left most commentators speechless is a mega-analysis [submitted by Krauss, whose research Taubes discusses, below - Paula] published in the American Journal of Clinical Nutrition (March 2010 91(3)535-546). Researchers combined the relative risk rates from twenty-one studies representing almost three hundred fifty thousand people whose diets and health outcomes had been followed for five to twenty-three years. The conclusion: "There is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD (coronary heart disease) or CVD (cardiovascular disease)." Not one word about this study appeared in the mainstream press.


    Low-carb diet trumps low-fat
    August 3, 2010 - 7:32am


    Associated Press Writer
    NEW YORK (AP) - Over the long term, a low-carb diet works just as well as a low-fat diet at taking off the pounds, and it might be better for your heart, new research suggests.

    Both diets improved cholesterol in a two-year study that included intensive group counseling. But those on the low-carbohydrate diet got a bigger boost in their so-called good cholesterol, nearly twice as much as those on low-fat.

    In previous studies, low-carb diets have done better at weight loss at six months, but longer-term results have been mixed. And there's been a suggestion of better cholesterol from low-carb eating.'

    The latest test is one of the longest to compare the approaches....The key difference was in HDL, or good cholesterol: a 23 percent increase from low-carb dieting compared to a 12 percent improvement from low-fat, said Gary Foster, director of Temple University's Center for Obesity Research and Education, who led the federally funded study.

    He said the low-carb boost is the kind one might get from medicines that improve HDL.
    "For a diet, that's pretty impressive," Foster said.

    The findings, published in Tuesday's Annals of Internal Medicine, are based on a study of 307 adults, two-thirds of them women. Participants were obese but didn't have cholesterol problems or diabetes.

    Half followed a low-carb diet modeled after the Atkins' plan and half went on a low-calorie, low-fat diet. All attended group sessions to help them change bad eating habits, get more active and stick to their diets.

    The volunteers had periodic checks of their weight, blood, bone density and body composition. After two years, there was no major differences between diet groups, except in good cholesterol. Why the low-carb diet had a bigger effect on good cholesterol isn't known, the researchers said.

    As low-carb plans became popular, experts feared the diet would drive up the risk of heart disease because it allows more fat. The latest results suggest those concerns are unfounded, Foster said. In the low-carb group, there was an early rise in "bad" cholesterol, the kind that builds up in arteries. But after two years, both groups ended up with similar improvements to bad cholesterol.

    The study's strengths include its size, length and its multiple locations _ Denver, Philadelphia and St. Louis, said Dr. William Yancy, of the Durham VA Medical Center in North Carolina.'

    "These are results we should have a lot of confidence in," said Yancy, who has done similar diet research but was not involved in the study.

    Foster, the study leader, said dieters should be less concerned about which diet to use, and focus on finding the support or technique _ like writing down what they eat _ that keeps them on track.

    "It doesn't make a difference for weight loss how you get there," he said.
    With the current obesity epidemic, more than one way is needed to attack the problem, Yancy said.

    "Both of these are options. These diets work," he said.

  3. Oops, I said "submitted by Krauss, whose research Taubes discusses, below..." This was cut-and-pasted from another email where I put in, from Good Calories, Bad Calories, Taube's discussion of Krauss, starting here:



    ..Kwiterovich and Sniderman...collaborated with Krauss on the last of his three papers on the heterogeneity of LDL. In 1983, they reported that the disproportionate elevation in the apo B protein in heart-disease patients was due to a disproportionate elevation in the amount of the smallest and densest of the low-density lipoproteins (very low-density lipoproteins, aka “VLDL” – PN).

    This explained what Krauss had set out to understand: why two people can have identical LDL-cholesterol levels and yet one develops atheroscle¬rosis and coronary heart disease and the other doesn't – why LDL cho¬lesterol is only a marginal risk factor for heart disease. (ETC.)

  4. Thanks Cynthia and Paula,

    Learn the lie and doubt the truth. That's really good.

    "You’re entitled to your own opinions. You’re not entitled to your own facts." - Moynihan


  5. The big problem is that truths about healthy eating get buried in an avalanche of information of mixed veracity. Lies about healthy eating get preferential treatment due to the financial clout of the edible oils, sweeteners, and food manufacturing industries.

    Having said that, I'm hopeful that the truth about added sugars and excessive omega-6 intake will eventually emerge into the limelight. The added sugars problem has been getting considerable press and research attention since about 2004. The omega-6 problem much less so outside of blogs such as this one. For example, Google "Case Study: 30-Days of High Omega-6 Diet--Stiffens Arteries and Increases Belly Fat."