by Marion Nestle

Search results: PURE study

Sep 5 2017

The PURE study warrants some skepticism

I love getting notes like this one from a reader:

Why aren’t you saying anything about the PURE study.  Doesn’t it prove that everything you’ve been saying about eating more fruits and vegetables and about saturated fat is wrong, wrong, wrong.  Admit it.

Not this time.  Whenever I hear the claim that “everything you thought about nutrition is wrong,” I know that skepticism is in order.  Science rarely works that way; it usually progresses incrementally.

What the PURE study is about: The PURE (Prospective Urban Rural Epidemiology) study was designed to examine, among other things, the effects of lifestyle behaviors on the health of about 135,000 people in 18 countries over up to 10 years.  Its results have just been published in Lancet journals.

What the headlines say: “Study challenges conventional wisdom on fats, fruits and vegetables.”

What the studies say:  Three papers report results: 

1,  Fruit, vegetable, and legumes vs. cardiovascular disease and death

Higher fruit, vegetable, and legume consumption was associated with a lower risk of non-cardiovascular, and total mortality. Benefits appear to be maximum for both non-cardiovascular mortality and total mortality at three to four servings per day (equivalent to 375–500 g/day).

2.  Fat and carbohydrate vs. cardiovascular disease and death

High carbohydrate intake was associated with higher risk of total mortality, whereas total fat and individual types of fat were related to lower total mortality. Total fat and types of fat were not associated with cardiovascular disease, myocardial infarction, or cardiovascular disease mortality, whereas saturated fat had an inverse association with stroke. Global dietary guidelines should be reconsidered in light of these findings.  [Note: the data do not distinguish types of carbohydrate.]

3.  Association of nutrients with blood lipids and blood pressure

Our data are at odds with current recommendations to reduce total fat and saturated fats. Reducing saturated fatty acid intake and replacing it with carbohydrate has an adverse effect on blood lipids. Substituting saturated fatty acids with unsaturated fats might improve some risk markers, but might worsen others.

Why the need for skepticism:

I like the way James Hamblin explains the problem in The Atlantic:

The practically important findings were that the healthiest people in the world had diets that are full of fruits, beans, seeds, vegetables, and whole grains, and low in refined carbohydrates and sugar.

As a writer and a reader, though, this is very boring. If I pitched that to my editor, he would laugh at me. What is new here? Why is this interesting? You know what would be novel? You getting fired! Now get out there and find me a story, dammit!

Why did they do this study?  

I looked immediately to see who paid for it.  The list of funders is very long (it must have been extremely expensive).  The list begins:

The PURE Study is an investigator initiated study funded by the Population Health Research Institute, the Canadian Institutes of Health Research (CIHR), Heart and Stroke Foundation of Ontario, support from CIHR’s Strategy for Patient Oriented Research (SPOR) through the Ontario SPOR Support Unit, as well as the Ontario Ministry of Health and Long­Term Care and through unrestricted grants from several pharmaceutical companies, with major contributions from AstraZeneca (Canada), Sanofi­Aventis (France and Canada), Boehringer Ingelheim (Germany and Canada), Servier, and GlaxoSmithkline, and additional contributions from Novartis and King Pharma and from various national or local organisations in participating countries [the funders that follow are mainly government and private research bodies along with a sugar trade association and more drug companies—the list takes up more than half a column].

Drug companies have a big interest in this topic, especially if dietary approaches to heart disease prevention aren’t proven.

What the PURE study really tells us: For this, I am going to quote from David Katz’s lengthy analysis:

On the basis of all of the details in these published papers, the conclusion, and attendant headlines, might have been: “very poor people with barely anything to eat get sick and die more often than affluent people with access to both ample diets, and hospitals.” One certainly understands why the media did NOT choose that! It is, however, true- and entirely consistent with the data.

Also, by way of reminder: the HIGHEST levels of both total fat, and saturated fat intake observed in the PURE data were still LOWER then prevailing levels in the U.S. and much of Europe, providing no basis whatsoever for headlines encouraging people already exceeding these levels to add yet more meat, butter, and cheese to their diets. Absolutely none.

My translation: This study confirms that the single most important risk factor for poor health is poverty.  The study results are consistent with the idea that largely plant-based diets are good for health.  No single study can settle the fat vs. carbohydrate debate because people eat complicated combinations of foods and diets containing those nutrients.  What we really need are well designed studies of dietary patterns—the ones done to date suggest that largely plant-based diets are associated with excellent health and longevity.  

Dec 2 2015

Funded study with negative result: Are ruminant trans fats healthier than industrial trans fats? Alas, no. The score: 80:7

Let’s take a look at a rare industry-funded study with results contrary to the interests of the funders.

It addresses the question: Is naturally occurring trans fat from meat and dairy products healthier than industrially produced trans fat?

The answer: not really.

The study

Vaccenic acid and trans fatty acid isomers from partially hydrogenated oil both adversely affect LDL cholesterol: a double-blind, randomized controlled trial.  Sarah K Gebauer, Frédéric Destaillats, Fabiola Dionisi, Ronald M Krauss, and David J Baer.  Am J Clin Nutr, November 11, 2015,  doi: 10.3945/ajcn.115.116129.

  • Conclusions: Total cholesterol (TC), LDL cholesterol, triacylglycerol, lipoprotein(a), and apolipoprotein B were higher after VA [vaccenic acid] than after iTFA [industrial trans fatty acids]; high-density lipoprotein (HDL) cholesterol and apolipoprotein AI also were higher after VA. Compared with control, VA and iTFA both increased TC, LDL cholesterol, ratio of TC to HDL cholesterol, and apolipoprotein B…VA also increased HDL cholesterol, apolipoprotein AI, apolipoprotein B, and lipoprotein(a)…whereas iTFA did not. c9,t11-CLA [conjugated linoleic acid] lowered triacylglycerol…and had no effect on other lipoprotein risk factors.
  • Funding:  Supported by USDA, Dairy Management Inc., Nestlé, and Dairy Australia. The funding organizations had no role in the conduct of the study; collection, management, analysis, and interpretation of the data; or decision to submit the manuscript for publication.

Background

Everyone agrees that hydrogenated fats containing trans fatty acids (industrial trans fatty acids or iTFAs) raise the risk of LDL-cholesterol (the bad one) and, therefore, the risk of coronary artery disease.  But what about the naturally occurring trans fats that occur in meat and dairy products as a result of bacterial hydrogenation of fats in the rumens of ruminant animals (ruminant trans fatty acids or rTFAs)?

Some studies suggest that rTFAs do not raise the risk of coronary disease.  This study tests that hypothesis.  It found that the major rTFA, vaccenic acid, does indeed raise risk factors for coronary artery disease almost or more than do iTFAs.

To make sense of the study, you need to know:

  • In iTFAs, the two major trans fats are elaidic acid 25%, and vaccenic acid 10%
  • In rTFAs, the trans fats are vaccenic acid 45% and elaidic acid 5%
  • Therefore, vaccenic acid is the major trans fat in rTFAs

What about Conjugated Linoleic Acid (CLA, or rumenic acid)?

The study also looked at intake of another rTFA, conjugated linoleic acid, which seems to have more benign properties but is present in such small amounts that it hardly makes a difference.  Although this study found CLA to have no effect on risk factors for coronary heart disease, a study from independently funded investigators judged it to have effects similar to that of other rTFAs.

What took so long to get this study published?

David Baer, who works for USDA, is the senior author on this paper.  I saw a slide presentation he did on this study in 2010.  Its results were already available.

In 2011, his group wrote a review of ruminant trans fats, but did not report these results (they were known, but not published).

In 2012, Dr. Baer wrote about ruminant trans fats, disclosed his dairy industry funding, but also did not report these results.  He concluded:

It is still difficult to draw definitive conclusions about the role of rTFAs in modulating risk of cardiovascular disease as mediated through changes in LDL and HDL cholesterol. Intake of these fatty acids is typically low in the diet.

I heard about this study last summer and wondered whether its funders were holding up publication.  I called Dr. Baer and asked.  He said the funders had nothing to do with the delay.  Instead, life had intervened—collaborators left, he was busy with other things, and was having trouble getting the paper published.

The bottom line

The study was done with purified vaccenic acid, not dairy fat, in amounts higher than those likely to be consumed in diets.  The authors say

Evidence…suggests that VA [vaccenic acid] consumed in amounts and foods typically found in the diet is inversely or not associated with CVD risk.

That’s one possible interpretation, but check the title of the editorial accompanying the paper: “In equal amounts, the major ruminant trans fatty acid is as bad for LDL cholesterol as industrially produced trans fatty acids, but the latter are easier to remove from foods.”

The funders of this study must be disappointed.  It was undoubtedly difficult and expensive to do, since it involved synthesis of pure vaccenic acid and a clinical trial of more than 100 subjects.

The funders must have hoped the study would show vaccenic acid to be as benign or even healthier than conjugated linoleic acid.  They bet wrong on this one.

This brings the score to 80:7 (sponsored studies with results favorable to the sponsor vs. those unfavorable).

Jan 19 2010

Cascadian Purely O’s: betrayal or business as usual?

Thanks to my NYU Medical Center colleague, Dr. Melissa Bender for the alert about the blogosphere fuss over Cascadian Farm Purely O’s cereals.  Apparently, Cascadian Farm, now owned by Big Food General Mills:

quietly changed the recipe for its “Purely O’s” cereal — previously an unsweetened favorite among children/toddlers – to include three times the sugar, as well as new fillers/sweeteners such as corn meal and tapioca syrup. They did this with no announcement on the label, taking advantage of those who trusted the brand for its previous simplicity. Loyal customers, particularly parents who had chosen this product because it was one of the few unsweetened options available, are outraged by this secretive yet major reformulation. Many discovered the change when their children spat out the cereal (myself included).

Her note sent me right to the largest of the three Whole Foods stores within walking distance of my Manhattan apartment.  Purely O’s: 3 grams of sugars, 3 grams of fiber, and 160 mg sodium per serving.

Oops: low-sugar, yes, but only medium-fiber and high in sodium.  Even with 0 grams of sugar, it’s not all that great.  Neither, for that matter, is its non-organic analog Cheerios (1 gram sugar, 3 grams fiber, 190 mg sodium).

At 3 grams of sugar per serving, Purely O’s is still lower in sugar than practically every other cereal in Whole Foods.  Whole Foods does not sell Big Food non-organics, so it does not carry Cheerios.  I had to look hard to find the only cereal lower in sugar than the reformulated Purely O’s: Arrowhead Mills Shredded Wheat, Bite Size (2 grams of sugar, 6 grams of fiber, and only 5 mg sodium).  That one, it seems to me, is a much better choice to begin with, pretty much in the same category as oatmeal (1 gram of sugar, 4 of fiber, and 0 mg sodium).  When it comes to cereal, more fiber the better.  Fiber is the point of breakfast cereal.

So I can’t get too upset about the reformulation of Purely O’s.  It’s simply a business decision, entirely to be expected from Big Food.  Cascadian Farms started out with “humble beginnings” as a maker of organic products, none of them cereals.  It was successful enough to be bought first by Small Planet Foods, and later by General Mills, which wanted to get in on the organic market.  Hence: organic Purely O’s.

General Mills is in business to sell cereal, and Purely O’s just didn’t make it past focus groups, as reported in the Boston Globe earlier this year.  General Mills must think there are too few of its deeply loyal customers to matter.  According to a business school case study, it has a history along these lines.  So chalk this one up to corporate imperatives.

Dr. Bender wrote to General Mills and received a reply that said as much:

Our goal is to give consumers quality products at a good value. Prior to introducing any product, extensive consumer testing is done. We conduct market research and product testing continuously to obtain consumer reaction to existing products and to changes being considered. Only when we feel confident that a product change will broaden its appeal will we alter a product’s formulation. We are sorry that you do not agree that the recent change in Cascadian Farm organic Purely O’s cereal was for the better.

If the bloggers are looking for a replacement, try oatmeal or those cute little bite-sized shredded wheat things.

May 24 2018

Pork (the meat, not goodies in the farm bill)

One of the industry newsletters I read regularly is GlobalMeatNews.com, which occasionally collects articles on specific topics into “special editions.”  This one is about pork.

Still the most-consumed meat in the world, the pork sector is shifting quickly with global markets opening for processors on a weekly basis. In this special newsletter, we look at the lucrative Chinese market that everyone is looking to break into, as well as work being done to tackle diseases in the pork sector.

A note on the pork study: it elicited a tirade in the New Food Economy about how so much of nutrition research is correlational and says little about causation.  The writer singles out the pork study as one of three examples of possible misuse of statistics.

Feeding infants puréed pork and increased body length? Trick question. P = 0.001—so something really seems to be happening. But does greater body length in infants actually matter? We’ll let the scientists pursue this one on their own until they come up with something that’s not just statistically significant but meaningful…The point isn’t to prevent you from snacking on prunes and chocolate while you shovel puréed pork into the baby. Do it if you want to, and given the marvelous powers of the placebo effect, you’ll probably be happy you did. But stop treating studies like these as if they contain the truth.

The study, no surprise, was sponsored by NIH but also by the National Pork Board, among other industry groups.  The Pork Board issued a press release: “New Study Finds Pureed Pork Supports Infant Growth.”

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Oct 5 2017

FoodNavigator-USA’s special edition on protein

Protein occurs in most foods but is especially abundant in meat, poultry, fish, dairy, eggs, grains, beans, nuts, and seeds.  Most of us get more than twice the amount we need on a daily basis.

But protein comes with a health aura.  It sells.

Hence: the food industry’s great interest in developing protein ingredients for food products.

FoodNavigator-USA, ever on top of current food trends, summarizes recent developments.

Special Edition: Protein in focus

While Americans typically get enough, there is no sign that the protein trend is going away, with growing numbers of food and beverage brands seeking to add additional protein to their wares or highlight the protein that’s always been there. We take a closer look…

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Jan 9 2017

FoodNavigator-USA’s Special Edition on Snack Foods

I always like to share FoodNaviagator-USA’s special editions—collections of articles on one theme, in this case, what’s happening with snacks from the industry’s perspective.

Special Edition: Snacking trends 

What’s hot in snacks? Sprouted grains? Posh jerky? Chickpeas? Gourmet marshmallows? What’s the difference between a meal and a snack, or are the lines becoming increasingly blurred? What’s a suitable portion-size? This FoodNavigator-USA special edition explores the hottest new trends and brands in the market.

Oct 7 2012

School lunch rules caught up in politics

Here’s my monthly (first Sunday) Food Matters column for the San Francisco Chronicle.  For links to appropriate resources and what to do to defend the new standards, scroll down to Friday’s post.

Nutrition and public policy expert Marion Nestle answers readers’ questions in this column written exclusively for The Chronicle. E-mail your questions to food@sfchronicle.com, with “Marion Nestle” in the subject line.

Q: Can you please explain to me why the USDA is restricting the number of calories in school lunches. It’s bad enough that school food is so awful that the kids won’t eat it. Now are they supposed to go hungry as well?

A: I don’t know whether to laugh or cry at a question like this or at the uproar over the U.S. Department of Agriculture’s new nutrition standards. As Comedy Central‘s Jon Stewart pointed out in his not-to-be-missed commentary on Sept. 27, if kids aren’t eating the food because they hate it, the calorie limits hardly matter. And if kids are hungry, the remedy is simple: Eat the food.

The new lunch standards hardly call for starvation rations. Kindergarteners through fifth-graders get up to 650 calories. The maximum is 700 for kids in grades six through eight, and 850 for high schoolers. All kids can have extra servings of vegetables. This ought to be plenty to get most of today’s kids – sedentary, underactive and prone to obesity as they are – through any school day.

Let’s face it. This uproar has nothing to do with school food. It has everything to do with election-year politics.

Some Republicans view school meals as convenient generator of emotional opposition to the incumbent president.

You don’t believe me? Take a look at the “No Hungry Kids Act” introduced by Reps. Steve King, R-Iowa, and Tim Huelskamp, R-Kan., both members of the House Agriculture Committee.

Their act would repeal the USDA’s hard-won nutrition standards and prohibit upper limits on calories. As King explains, this is to undo “the misguided nanny state, as advanced by Michelle Obama’s Healthy and Hunger-Free Kids Act.”

You can’t make this stuff up.

Let me briefly review where these standards came from. In 2004, Congress required school districts to develop wellness policies, but left the details up to the districts. In part to resolve the resulting inconsistencies, Congress asked the USDA to develop new nutrition standards. In turn, the USDA asked the Institute of Medicine to study the situation and make recommendations.

The institute’s 2009 report called for aligning school meals with the Dietary Guidelines for Americans by increasing fruits, vegetables and whole grains, but reducing saturated fat, sodium and calories. It suggested encouraging students to try new vegetables by establishing weekly requirements for various kinds, but to limit starchy vegetables like potatoes to one cup a week.

In 2010, Congress passed the Healthy, Hunger-Free Kids Act which required the USDA to set nutrition standards for all food sold and served in schools, not only at breakfast and lunch, but also at any time during the school day. The USDA used the institute’s report as a basis for its proposals.

These, you may recall, got the USDA in trouble with lobbyists for businesses that supply French fries and pizza to schools. The Senate intervened and amended the agriculture spending bill to say that none of its funds could be used to “set any maximum limits on the serving of vegetables in school meal programs” or “require crediting of tomato paste and puree based on volume.” The results include no weekly limits on French fries; a dab of tomato paste on pizza now counts as a vegetable serving.

With these allowances in place, the USDA released the new standards in January. Most observers viewed them as an important accomplishment of the first lady’s Let’s Move campaign to end childhood obesity within a generation.

What about student outrage that the new meals leave them hungry? As a strong supporter of student activism, I applaud students getting involved in protests. Their actions have already persuaded Agriculture Secretary Tom Vilsack to tell kids to eat healthy snacks if they are hungry.

Perhaps student activism around calories will be a first step toward advocacy for more substantive goals for their education and wellness: more and better paid teachers, better educational materials, more sensible testing, better quality food in schools, and instruction in how to grow, harvest and cook food.

But where, I wonder, are the adults in all of this? Childhood obesity is not trivial in its consequences for many kids, and school food ought to be a model for how healthy, delicious food is normal fare.

Schools in which adults – principals, teachers, school food personnel and parents – care about what kids eat and act accordingly are setting examples that what kids eat matters just as much as what kids learn.

It’s shameful that elected officials would attempt to undermine the health of America’s children for partisan political purposes.

Marion Nestle is the author of “Why Calories Count: From Science to Politics,” as well as “Food Politics” and “What to Eat,” among other books. She is a professor in the nutrition, food studies and public health department at New York University, and blogs at foodpolitics.com. E-mail: food@sfchronicle.com

May 29 2012

The latest battle in the supplement wars: FDA v. DMAA

Welcome to the largely unregulated universe of dietary supplement marketing, in this case of DMAA, a.k.a. 1,3-dimethylamylamine, methylhexanamine, or geranium extract (from which it is supposedly isolated).
DMAA is supposed to stimulate athletic performance.
In April, the FDA sent letters warning ten DMAA distributors that it considered their products adulterated because:
  • DMAA does not naturally come from a food.
  • Most of it is produced synthetically
  • It might not be safe.
The FDA received 42 complaints of adverse events associated with taking DMAA supplements.  Although the reports do not prove that DMAA caused the problems, these are serious: cardiac disorders, nervous system disorders, psychiatric disorders, and death.The FDA says:

dimethylamylamine narrows the blood vessels and arteries, which increases cardiovascular resistance and frequently leads to elevated blood pressure. This rise in blood pressure may increase the work of the heart such that it could precipitate a cardiovascular event, which could range from shortness of breath to tightening of the chest and/or a possible myocardial infarction (heart attack).

One FDA warning letter went to a company called Muscle Warfare for its DMAA supplement “Napalm” which “produces intense sensations of power, drive, energy, focus, motivation, and awareness.  Enormous strength, speed and endurance increases may result.”

Here’s how the company says Napalm works:

Upon ingestion, energy is almost instantly kicked in with Air Strike while core body heat is dramatically supported. This extra body heat may then dramatically support the release of heat shock proteins, during your workout by way of our patent pending Thermobraic Heat Shock Protein Deployment System via Myobolic-SERMS/1&2….Muscle Pumps are fueled via a remarkable creatine free, Plasma Scorch Muscle Engorgement Agent….

Just pure power and dry hard size. Anabolism is kicked in by your ultra-intense workout coupled with our powerful mTOR pathways inducing Vaso-Anabolic Branched Chain Amino Acid Blend. Further hormonal anabolic support is induced by our patent pending NMDA™ hormonal support agent. NMDA™ specifically targets growth hormone, testosterone, IGF-1 and IGF-2 release and has been scientifically shown to provide dramatic support!

As I keep saying, you can’t make this stuff up.

The supplement industry, ever eager to find an athletic supplement that everyone will want to take has reacted with outrage to the FDA’s warning letters (see NutraIntredients-USA.com for a series of articles on DMAA).

Since Congress passed the Dietary Supplement Health and Education Act (DSHEA) in 1994, the supplement industry has gotten a virtually free pass on regulation and its less scrupulous members push the limits of marketing to the point where the FDA has no choice but to act.

DMAA supplement marketers now argue that if DMAA comes from geraniums, synthetic DMAA should be legal. 

I had no idea people were eating geraniums, but never mind.  The flowers may not contain DMAA anyway.

According to NutraIngredients, most DMAA is synthetic (hence: not natural):

There is only one study repeatedly referenced to show that DMAA is a naturally occurring constituent of geranium oil (Ping, Z.; Jun, Q. & Qing, L. (1996), ‘A Study on the Chemical Constituents of Geranium Oil, Journal of Guizhou Institute of Technology 25 (1): 82–85) – which analytical testing experts contacted by NutraIngredients-USA say is “not scientifically defensible“.

The supplement industry views the warning letters as signs that the FDA is going to start giving its products greater scrutiny.

That would be a step in the right direction, but maybe the FDA won’t have to.  The warning letters elicited a flood of  class action lawsuits against DMAA.

If the FDA won’t or can’t act, lawyers will take up the burden of regulating potentially unsafe and misleadingly marketed supplements.

Update, June 29:  Oops.  Investigators fail to find DMAA in geranium extracts or oils.