Search results: dietary guidelines

I could not keep up with the number of e-mails I got last week with the subject line “Have you seen this?”

“This” referred to an opinion piece in JAMA entitled Backlash Over Meat Dietary Recommendations Raises Questions About Corporate Ties to Nutrition Scientists.

Definitely up my alley.

The article describes the outraged reaction to a series of papers in the Annals of Internal Medicine last year arguing that recommendations to eat less meat are unfounded (I posted about this at the time).  Some of the investigators involved in the meat papers turned out to have undisclosed ties to meat industry interests.

The JAMA article points out that the most outraged objections to the Annals papers came from investigators who have plenty of industry ties (plant-based) of their own.

My book, Unsavory Truth: How Food Companies Skew the Science of What We Eat, provides loads of evidence for a basic observation: research funded by food companies, regardless of the particular food studied, tends to produce results favorable to the sponsor’s interests.

It also describes how industry influence occurs at an unconscious level; recipients are unaware that they are being influenced.

How the influence gets expressed is also the subject of research.  Bias most frequently turns up in the framing of the research question.  It also turns up frequently in the interpretation of results.

Here is an example from a study of a healthy plant food—walnuts.

The study: Effect of a 2-year diet intervention with walnuts on cognitive decline. The Walnuts And Healthy Aging (WAHA) study: a randomized controlled trial.  Aleix Sala-Vila, Cinta Valls-Pedret, Sujatha Rajaram, Nina Coll-Padrós, Montserrat Cofán, Mercè Serra-Mir,  Ana M Pérez-Heras, Irene Roth, Tania M Freitas-Simoes, Mónica Doménech, Carlos Calvo, Anna López-Illamola, Edward Bitok, Natalie K Buxton, Lynnley Huey, Adam Arechiga, Keiji Oda, Grace J Lee, Dolores Corella, Lídia Vaqué-Alcázar, Roser Sala-Llonch, David Bartrés-Faz, Joan Sabaté, and Emilio Ros1.  Am J Clin Nutr 2020;00:1–11.

Conclusions: Walnut supplementation for 2 y had no effect on cognition in healthy elders. However, brain fMRI and post hoc analyses by site suggest that walnuts might delay cognitive decline in subgroups at higher risk. These encouraging but inconclusive results warrant further investigation.

Conflicts of Interest: AS-V, SR, JS, and ER have received research funding through their institutions from the California Walnut Commission, Folsom, CA, USA. JS and ER were nonpaid members of the California Walnut Commission Scientific Advisory Council. ER was a paid member of the California Walnut Commission Health Research Advisory Group. JS has received honoraria from the California Walnut Commission for presentations.  AS-V has received support from the CaliforniaWalnut Commission to attend professional meetings. All other authors report no conflicts of interest.

Comment: This looks to me like a classic example of interpretation bias.  Although the study showed no effect of walnut supplementation, the authors interpret its overall results as encouraging.  This is putting a positive spin on null results.

Walnuts—and other kinds of nuts—are plant foods with healthy fats.  Why does the California Walnut Commission need to do this?  So you will buy walnuts rather than hazelnuts, pecans, or macadamia nuts (all of which are sponsoring their own positive-result studies).  Studies like these are mostly about marketing.

Questions of whether meat is healthy or unhealthy—and, if unhealthy, at what level of intake—are about much more than marketing.   They need to be studied as objectively as possible.  It’s best to keep industry influence far away from such studies.

Even if the science is done well from start to finish, researchers’ ties to food company sponsors give the appearance of conflicted interests.  Such ties are best avoided from the get-go.

Follow-up

• A detailed analysis of the JAMA piece by the anonymous CarbSane blog
• Naomi Oreske’s comment in Scientific American
• Texas A&M’s letter to Harvard requesting an investigation of faculty belonging to True Health Initiative (who complained about the meat guidelines)
• Texas A&M’s Chancellor Calls on Harvard to Look Into Faculty’s Beef-science Ethics (AgDaily)
• Beef with Harvard (Inside Higher Ed)
• From Beef to Bots? Harvard Professors Mired in Debate over Spam Emails, Industry-Funded Research (Harvard Crimson)
• Conflict of Interest in the Post-Truth Era: What Is It, Now? (David Katz)
• Processed Meat “Guidelines:” Why the Exceptional Reaction? (David Katz)
• Tobacco, Soda, and the Beef with Truth (David Katz)
• Massive Meat Mayhem, Part 3 (ConscienHealth)
• Perspective: Red and Processed Meats and Health Risks: How Strong Is the Evidence? (Frank Hu et al)

This is one of an ongoing series of examples of how industry funding skews, or to be more precise, is strongly associated with skewing, of research and opinion about matters of diet and health.

This example is an analysis of the scientific rigor of dietary approaches to controlling type 2 diabetes through diet.  The authors looked at the evidence for efficacy of the DASH, Mediterranean, Plant-Based, and Low-Carb diets.

Improving the Scientific Rigor of Nutritional Recommendations for Adults with Diabetes: A Comprehensive Review of the American Diabetes Association Guidelines Recommended Eating Patterns.  Hallberg S, Dockter NE, Kushner J, Athinarayanan S.  Preprints 2019.  Online March 5.  doi: 10.20944/preprints201812.0187.v2

Conclusion: “Our review of the current Standards and Recommendations finds significant shortcomings regarding scientific review methodologies, which are likely to translate to suboptimal clinical care decisions for patients with T2D.”  The study dismisses most studies of the DASH, Mediterranean, and Plant-based diets as poorly done or otherwise inappropriate for their review.  For the DASH diet, it says more research is needed.  It calls for more research on whether the benefits of Mediterranean diets are due to low carb or healthy fats, and suggests that the benefits of plant-based diets may be due to weight loss.  The best evidence supports the Low-Carb diet: “Evidence from 30 trials and 10 follow-up studies demonstrates that a low-carbohydrate diet is an effective dietary approach for addressing dyslipidemia.”

Conflict of Interest Statement:  SJH is an employee and shareholder of Virta Health, a for-profit company that provides remote diabetes care using a low-carbohydrate nutrition intervention, and serves as an advisor for Atkins Corp.  NED is a paid consultant for Virta Health.  JAK serves as medical director of McNair Interests, a private equity group with investments in type 1 diabetes and other chronic illnesses, and is also an advisor for Sanofi and Lexicon.

Comment:    All authors are employed by or consult for a company that uses low-carb dietary approaches in its for-profit business.  As I explain in Unsavory Truth, the influence of industry funding is often unconscious, unintentional, and unrecognized.  Nevertheless, the opinions of the authors can be predicted from their financial connections to Virta Health.

Dr. Robert Lustig notes that the American Diabetes Association (ADA) has just released its newest guidelines for management of type 2 diabetes in children.

He has plenty to say about this organization, its ties to the pharmaceutical industry, and its lack of focus on effective dietary approaches to prevention and treatment—at a time when “insulin prices have soared into the stratosphere.”

The ADA, he says,

is a “bought” organization. Bought by Big Pharma. It’s only about the money. It’s not about lives or health or society. This is extortion. Big Food is Al Capone. And the ADA is Frank Nitti, his henchman.

The ADA recommendations do talk about physical activity and diet, but judge the evidence for them as not particularly strong (grades B and C).

These are standard recommendations, but difficult to follow consistently, not least because they are not nearly forceful or specific enough.

Dr. Lustig would like much greater emphasis on restricting sugars.  That’s a good place to begin.

The British government is serious about reducing sugars, especially in the diets of children.  Its agency, Public Health England (PHE), has been hard at work for several years.

In 2014, it issued a report announcing plans for initiatives to reduce overall sugar intake: Sugar Reduction: Responding to the Challenge.

In 2015, its report provided evidence for why eating less sugar is necesssary: Sugar Reduction: The Evidence for Action.

The Scientific Advisory Committee on Nutrition (SACN) has concluded that the recommended average population maximum intake of sugar should be halved: it should not exceed 5% of total dietary energy. SACN also recommended that consumption of sugar sweetened drinks should be minimized by both adults and children. By meeting these recommendations within 10 years we would not only improve an individual’s quality of life but could save the NHS, based on a conservative assessment, around £500 m every year.

In 2016, a different agency of the UK government issued a plan for action to reduce childhood obesity. Among other recommendations, the plan called for taxes on soft drinks, but it also challenged the food and beverage industries to reduce sugars in products aimed at children by at least 20% by 2020, including a 5% reduction in the first year.  It said companies could do this by reducing sugar levels in products, reducing portion size, or shifting purchases to lower sugar alternatives.

In 2017, Public Health England set targets: Sugar Reduction: Achieving the 20%.

The role for Public Health England (PHE) is to advise government on setting the sugar reduction guidelines per 100 g of product and the calorie or portion size guidelines for specific single serving products. PHE is committed to publishing the category-specific guidelines for the nine initial categories of food in March 2017 and this report fulfills that commitment.

The guidelines are quite precise:

The good news: everyone has to do this so it will be an across-the-board reduction.

The not-so-good news: the reports say not one word about enforcement.

Public Health England plans follow-up reports.  Stay tuned.

• For a quick summary, see FoodManufacture.co.uk
• For the candy industry’s take, see ConfectionaryNews.com

Yesterday, the FDA opened for public comment its long-awaited guidance for industry about reducing salt in processed food products.  The guidance affects about 150 products.  It gives baseline data for those products and sets targets for salt reduction.

Please note that I am using the word salt, not sodium.  The targets are for sodium reduction.  Most dietary sodium comes from salt added to processed foods and pre-prepared foods.  Salt is 40% sodium.  The target dietary intake of 2300 mg sodium comes to just under 6 grams of salt a day, which is not particularly low.  It is, however, lower than current intake levels.

In a blog post, FDA official Susan Mayne said the link between sodium intake and blood pressure is “strong and well documented,” but

In fact, it’s very difficult in the current marketplace NOT to consume too much sodium. The average intake today is over 3,400 milligrams—significantly more than the 2,300 milligram limit recommended by federal guidelines. And it’s not just adults who are eating too much sodium: Children and teens consume more than is recommended.

Vox, for example, provides a terrific chart on the amounts of sodium in foods.  It starts with this:

Susan Mayne goes on to explain that

the FDA assessed the sodium content of thousands of products in the marketplace and engaged with experts in industry, academia, and government to get the best available scientific and technical input. We know that sodium has important functions in many foods, such as taste, texture, and microbial safety… Our approach encourages gradually reducing sodium in the majority of foods that contain it…Moreover, our draft targets apply to processed and prepared foods that are eaten both at home and outside the home.

Despite the voluntary nature of the guidance and the lengthy timeline (up to ten years) for implementation, the makers of processed foods are sure to object.  At their urging, the House committee on appropriations, in draft report language, urged the FDA to postpone guidance on salt until the CDC and Institute of Medicine update the Dietary Reference Intake standards for sodium intake.

The Salt Institute, the trade association for the salt industry, issued a press release charging malpractice:

The issuance today of new “voluntary” sodium reduction mandates by the FDA is tantamount to malpractice and inexcusable in the face of years of scientific evidence showing that population-wide sodium reduction strategies are unnecessary and could be harmful. This effort will limit the food choices of Americans, not increase them as the FDA claims. It will make our food less safe and endanger public health.

In JAMA, CDC Director Thomas Frieden rebuts the scientific arguments point by point and, in my view, demolishes them.  He explains how important this initiative is to public health:

Thirty-nine countries have established sodium targets for foods and meals, with 36 of those adopting voluntary approaches. Setting targets helps create a level playing field for the food industry, supporting reductions already begun by companies such as Walmart, Darden, Unilever, PespsiCo, General Mills, Mars, Nestlé, and others. The United Kingdom set voluntary sodium reduction targets in 2003; from 2003 to 2011 sodium intake decreased 15%. During this same period, average blood pressure decreased, and, following no change in prior years, deaths from ischemic heart disease and stroke decreased by approximately 40% [the reference for this last statement is BMJ Open. 2014;4(4):e004549].

Most people would be healthier cutting down on salt intake.  Food company executives know this.  Politico Morning Agriculture points out that some Big Food companies have joined the public health community in supporting the FDA’s proposal.

The band of strange bedfellows – the American Heart Association, Mars, Academy of Nutrition and Dietetics, Nestlé, PepsiCo, American Public Health Association, Unilever and the Center for Science in the Public Interest – all signed on to a letter last month to Senate Appropriations ag subcommittee Chairman Jerry Moran and ranking member Jeff Merkley to support the FDA on sodium. Find that here.

From a public health perspective, the FDA initiative is a step in the right direction but could go further.  It should have required mandatory salt reduction.  Judging from the Salt Institute’s reaction, this is still a big step.  The New York Times quotes Michael Jacobson:

“The F.D.A. found a sweet spot between doing nothing and regulating…This will at least give the public benchmarks against which we can gauge sodium content of foods.”

FDA resources:  

• Federal Register Notice.  The home page explains how to submit comments by October 31 to Docket No. FDA-2014-D-0055
• Draft Guidance Document in PDF (132KB)
• Draft Food Categories and Draft Voluntary Targets for Sodium Reduction (Appendix Table 1) (XLSX: 43KB)
• Summary Explanation of the Draft Food Categories and Draft Voluntary Targets for Sodium Reduction (Appendix Table 1) (PDF: 277KB)
• Sodium Reduction At A Glance
• Presentation: FDA’s Voluntary Sodium Reduction Initiative (PPTX 3MB) 
• Constituent Update: FDA Issues Draft Guidance to Industry for Voluntarily Reducing Sodium
• Blog: Reducing Sodium in the Food Supply
• At a Glance: Lowering Sodium in the Food Supply
• Frequently Asked Questions on FDA’s Sodium Reduction Strategy
• Additional Information and History of Actions on Sodium Reduction

Australia has government-sponsored front-of-package nutrient labeling—the Health Star system—that looks a lot like the U.S. grocery industry’s Facts Up Front, but is even more favorable to manufacturers of processed foods.

As I explained a few years ago, Facts Up Front was a successful scheme by the Grocery Manufacturers and Food Marketing Associations to head off the FDA’s attempts to put traffic-light signals on the front of processed food products (here’s more of the back story).

Like the U.S. system, the Australian system is voluntary.  Unlike it, Health Stars are prominent and convey the impression that the more starts, the better.

A year into the program, Australian newspapers are writing about how companies are “gaming” the system:

Deakin University professor of public health nutrition Mark Lawrence said the health star rating system was being exploited as a marketing tool by junk food manufacturers to make consumers think their food was healthy. He said the scheme for packaged food undermined the public health message that people should eat fresh, unprocessed food.

This article quotes a statement by Kellogg that sales of Nutrigrain cereal went up after the company reformulated the product to raise its rating from 2 to 4 stars.

But isn’t reformulation a good thing?  It could be but just because a processed food is “better-for-you,” does not necessarily make it a good choice.

Professor Mark Lawrence of Deakin and Christina Pollard of Curtin University write:

Its main design limitation is that it simplistically frames the cause of, and solution to, dietary imbalances in terms of nutrients. This is fundamentally at odds with the latest nutrition advice, which uses a food-based approach…So what the health star rating system ends up doing is encouraging marketing of unhealthy or discretionary foods, as healthy options.

Overall, they point out:

Part of the problem is that the campaign’s main message – “the more stars the better” – is misleading…The actual health message is to eat more of these [recommended healthy] foods; it’s not that we should try to eat food with more stars.

Good advice.

Thanks to a reader for sending these items from a journal that I don’t usually come across.  These bring the casually collected total since last March to 145 studies favorable to the sponsor versus 12 that are not.

Consuming the daily recommended amounts of dairy products would reduce the prevalence of inadequate micronutrient intakes in the United States: diet modeling study based on NHANES 2007–2010.  Erin E Quann, Victor L Fulgoni III and Nancy Auestad. Nutrition Journal 2015; 14:90 DOI: 10.1186/s12937-015-0057-5

• Conclusion: Increasing dairy food consumption to recommended amounts is one practical dietary change that could significantly improve the population’s adequacy for certain vitamins and minerals that are currently under-consumed, as well as have a positive impact on health.
• Funding: The study and the writing of the manuscript were supported by Dairy Management Inc.

Association of lunch meat consumption with nutrient intake, diet quality and health risk factors in U.S. children and adults: NHANES 2007–201Sanjiv Agarwal, Victor L. Fulgoni III and Eric P. Berg. Nutrition Journal. 2015;14:128.  DOI: 10.1186/s12937-015-011f8-9

• Conclusions: The results of this study may provide insight into how to better utilize lunch meats in the diets of U.S. children and adults.
• Funding: The present study was funded by North American Meat Institute.

A review and meta-analysis of prospective studies of red and processed meat, meat cooking methods, heme iron, heterocyclic amines and prostate cancer.  Lauren C. Bylsma and Dominik D. Alexander.  Nutrition Journal. 2015;14:125. DOI: 10.1186/s12937-015-0111-3

• Conclusion: Dose-response analyses did not reveal significant patterns of associations between red or processed meat and prostate cancer….although we observed a weak positive summary estimate for processed meats.
• Funding: This work was supported in part by the National Cattlemen’s Beef Association (NCBA), a contractor to the Beef Checkoff. NCBA did not contribute to the writing, analysis, interpretation of the research findings, or the decision to publish…LCB and DDA are employees of EpidStat Institute. EpidStat received partial funding from the National Cattlemen’s Beef Association (NCBA), a contractor to the Beef Checkoff, for work related to this manuscript. The conceptualization, writing, analysis, and interpretation of research findings was performed independently.

Are restrictive guidelines for added sugars science based?  Jennifer Erickson and Joanne Slavin.  Nutrition Journal. 2015;14:124.  DOI: 10.1186/s12937-015-0114-0

• Conclusion: However, there is currently no evidence stating that added sugar is more harmful than excess calories from any other food source. The addition of restrictive added sugar recommendations may not be the most effective intervention in the treatment and prevention of obesity and other health concerns.
• Disclosure: Jennifer Erickson, is a PhD student in Nutrition at the University of Minnesota working with Dr. Joanne Slavin. Joanne Slavin is a professor in the Department of Food Science and Nutrition, University of Minnesota.  In the past 5 years, she has given 150 scientific presentations in 13 countries. Many of these meetings received sponsorship from companies and associations with an interest in carbohydrates and nutritive sweeteners…Her research funding for the past 5 years has included grants from General Mills, Inc., Tate and Lyle, Nestle Health Sciences, Kellogg Company, USA Rice, USA Pears, Minnesota Beef Council, Minnesota Cultivated Wild Rice Council, Barilla Company, USDA, American Egg Board, American Pulse Association, MNDrive Global Food Ventures, International Life Science Institute (ILSI), and the Mushroom Council. She serves on the scientific advisory board for Tate and Lyle, Kerry Ingredients, Atkins Nutritionals, Midwest Dairy Association and the Alliance for Potato Research and Education (APRE). She holds a 1/3 interest in the Slavin Sisters Farm LLC, a 119 acre farm in Walworth, WI.

Cow’s milk-based beverage consumption in 1- to 4-year-olds and allergic manifestations: an RCT.  M. V. Pontes, T. C. M. Ribeiro, H. Ribeiro, A. P. de Mattos, I. R. Almeida, V. M. Leal, G. N. Cabral, S. Stolz, W. Zhuang and D. M. F. Scalabrin.  Nutrition Journal. 2016;15:19.  DOI: 10.1186/s12937-016-0138-0

• Conclusion: A cow’s milk-based beverage containing DHA, PDX/GOS, and yeast β-glucan, and supplemented with micronutrients, including zinc, vitamin A and iron, when consumed 3 times/day for 28 weeks by healthy 1- to 4-year-old children was associated with fewer episodes of allergic manifestations in the skin and the respiratory tract.
• Funding: This study was funded by Mead Johnson Nutrition…The study products were provided by Mead Johnson Nutrition. Dr. Scalabrin, S. Stolz, and W. Zhuang work in Clinical Research, Department of Medical Affairs at Mead Johnson Nutrition. All of the remaining authors have no financial relationships to disclose.

Whole grain consumption trends and associations with body weight measures in the United States: results from the cross sectional National Health and Nutrition Examination Survey 2001–2012.  Ann M. Albertson, Marla Reicks, Nandan Joshi and Carolyn K. Gugger.  Nutrition Journal 2016;15:8.  DOI: 10.1186/s12937-016-0126-4

• Conclusions: The data from the current study suggest that greater whole grain consumption is associated with better intakes of nutrients and healthier body weight in children and adults. Continued efforts to promote increased intake of whole grain foods are warranted.
• Competing interests:  Marla Reicks received an unrestricted gift from the General Mills Bell Institute of Health and Nutrition during the manuscript preparation to support research at the University of Minnesota.  Carolyn Gugger and Nandan Joshi are current employees and stockholders of General Mills, Inc.  Ann Albertson was an employee of General Mills, Inc during the conception, analysis and initial preparation of the manuscript. She is currently retired from General Mills.
• Non-financial competing interests: General Mills, Inc is a global consumer foods company that manufactures and sells products across a broad variety of food categories, including grain-based foods. General Mills product portfolio includes ready-to-eat cereals, cereal bars, baked goods, flour, and salty snacks that may contain whole grain.