Search results: dietary guidelines

Here’s another nutrition question that doesn’t go away.

This new study is just out: Egg and cholesterol consumption and mortality from cardiovascular and different causes in the United States: A population-based cohort study.

Its conclusion:

In this study, intakes of eggs and cholesterol were associated with higher all-cause, CVD, and cancer mortality. The increased mortality associated with egg consumption was largely influenced by cholesterol intake. Our findings suggest limiting cholesterol intake and replacing whole eggs with egg whites/substitutes or other alternative protein sources for facilitating cardiovascular health and long-term survival.

This gets right into the funny business of the 2015 Dietary Guidelines.  As I explained,

the recommendation to limit cholesterol has been dropped [from the 2015 Guidelines], but the document says, confusingly, that “this change does not suggest that dietary cholesterol is no longer important to consider when building healthy eating patterns. As recommended by the IOM, individuals should eat as little dietary cholesterol as possible while consuming a healthy eating pattern.”  Could the dropping of the limit have anything to do with egg-industry funding of research on eggs, the largest source of dietary cholesterol, and blood cholesterol?  The Physicians Committee for Responsible Medicine has just filed a lawsuiton that very point.

Well, here we go again.  My thoughts:

This is association, not causation.  The paper gives this caveat: “At baseline, participants with higher whole egg consumption had a higher BMI and lower household income. They were less educated, less physically active, more likely to smoke and have a high cholesterol level, and less likely to take aspirin. They also had higher red meat intake; lower intakes of fruit, dairy products, and sugar-sweetened beverages; and lower HEI-2015 score.”

Eggs, it seems, track with other unhealthful dietary behaviors.

The egg situation is a mess to sort out because the egg industry funds so many studies in its own defense and these invariably show no effect.

But eggs are one food in complicated diets and it’s really hard to look at them independently of everything else in the diet and lifestyle.

What to do?  Moderation is always good advice.

This report documents how government policies—in the U.S. and internationally—promote and protect makers of booze, wine, and beer, despite the demonstrably harmful effects of those products on health and society.

How do governments do this?

• Development assistance
• Tax breaks
• Tax rebates
• Marketing deductions
• Production subsidies
• Trade agreements

Why do they do this?  Lobbying and tax revenues.

If you want to understand why the USDA and HHS “found no evidence” for reducing the alcohol recommendation in the 2020 Dietary Guidelines, read this report.

If you are a marketer of fruit juice, you have a problem.  Fruit juice has a lot of sugar and retains little of the fiber of whole fruit.  Dietary recommendations increasingly suggest limits on the amounts consumed, especially for children.

But according to the trade group, the Juice Products Association, “The 2015 Dietary Guidelines for Americans and the American Academy of Pediatrics (AAP) concur that 4 to 6 ounces of 100% fruit juice per day is appropriate for young children. For children age 7 and older, the AAP recommends a daily serving of 8 to 12 ounces per day.”

No it does not!  The American Academy of Pediatrics suggests a limit to that amount.  Big difference.

Juice should not be introduced into the diet of infants before 12 months of age unless clinically indicated. The intake of juice should be limited to, at most, 4 ounces/day in toddlers 1 through 3 years of age, and 4 to 6  ounces/day for children 4 through 6 years of age. For children 7 to 18 years of age, juice intake should be limited to 8 ounces or 1 cup of the recommended 2 to 2.5 cups of fruit servings per day.

What about adults?  Adults do not need more sugars or the calories they provide.   They too would be better off eating fruit.

Juice trade associations to the rescue.

The study:  100% Fruit juice intake and cardiovascular risk: a systematic review and meta-analysis of prospective and randomised controlled studies. Lanfranco D’Elia, et al.  European Journal of Nutrition (2020)

Methods: This is a meta-analysis of prospective studies and randomized controlled trials (RCTs) examining the relationship between consumption of 100% fruit juice (FJ) and the risk of cardiovascular disease (CV).

Conclusions: “The results of these analyses indicate that 100%FJ consumption is not associated with higher CV risk. A non-linear inverse dose–response relationship occurs between 100%FJ consumption and CV disease, in particular for risk of stroke, probably mediated by the decrease in blood pressure.”

Funding: “Open access funding provided by Università degli Studi di Napoli Federico II within the CRUI-CARE Agreement. This project was funded by the European Fruit Juice Association (AIJN) via an unrestricted grant. AIJN was not involved in the design, conduction, analysis and interpretation of the results.”

Comment: Why would anyone think that fruit juice, of all things, would be associated with heart disease risk?  You would have to be drinking a lot of it —at the exclusion of healthier foods—for it to make  a significant difference.  The only point of this study is to try to convince adults to drink more juice.  When I was a kid, fruit juice was expensive and we drank it in 4-ounce glasses.  If you drink fruit juice at all, that’s still a good idea.

Rebecca Earle.  Feeding the People: The Politics of the Potato.  Cambridge University Press, 2020.

The historian Rebecca Earle uses the potato as an entry point into investigations of some of the most important political issues of our time: immigration, free-market capitalism, and globalization.  As she puts it, her book

offers a deep history of the concept of food security and fresh account of how eating became part of modern politics.  It also helps to explain our own fraught relationship with dietary guidelines by showing how healthy eating became embedded within a neoliberal framework valorising personal responsibility and choice rather than state-led intervention” (p. 3).

A couple more excerpts to give you an idea where she is headed with this.  Malthus, she says, had a “dismal vision of catastrophic population increase.”  With this vision

came pessimism about the potato’s capacity to contribute to national well-being.  Far from increasing trade and boosting economic exchange, the potato bcame an obstacle to modernity, because it helped sustain precisely the sectors of the population that capitalism aimed to eradicate” (p. 141).

Later, she describes the Peruvian International Potato Center (its Spanish acronym is CIP):

Peru is not alone in its gastronational celebration of local potato varieties.  A number of countries, from Denmark to Ecuador, have likewise established national potato days, or sought to protect specific varieties under international legislation…International regulatory structures thus help to nationalise potatoes by according them formal status as part of the national patrimony.  Its long history as an overlooked, localised food resource now enables the potato to toggle between the global food system and notions of culinary heritage, in a way that other major commodities such as sugar or maize have largely failed to do (pp. 197-198).

I read a report in the Washington Post discussing a study done by Neal Barnard and his colleagues associated with the Physicians Committee for Responsible Medicine, a group advocating for plant-based diets and animal welfare.

More than 85 percent of the studies in Barnard’s meta-analysis, whether funded by industry or not, showed that eggs have unfavorable effects on blood cholesterol. Industry-funded studies, Barnard found, were more likely to play down these findings.

The study, a meta-analysis, reviewed 153 studies examining the effects of eggs on blood cholesterol levels.  It found the proportion of egg studies funded by the egg industry to have increased since 2010, and the industry-sponsored results to be spun—no surprise—in favor of the benefits of eggs.

This matters because advice in the 2015-2020 Dietary Guidelines for Americans is unhelpful about eggs.

Here’s how I explained the confusion in my January 7, 2016 post:

Cholesterol: the recommendation to limit cholesterol has been dropped, but the document says, confusingly, that “this change does not suggest that dietary cholesterol is no longer important to consider when building healthy eating patterns. As recommended by the IOM, individuals should eat as little dietary cholesterol as possible while consuming a healthy eating pattern.”  Could the dropping of the limit have anything to do with egg-industry funding of research on eggs, the largest source of dietary cholesterol, and blood cholesterol?  The Physicians Committee for Responsible Medicine has just filed a lawsuit on that very point.

The lawsuit was about undue influence of the egg industry, but the judge threw the suit out of court because no legal standard exists for undue influence.  Oh.

What to do about eggs?  I vote for moderation, of course.

This one was sent to me by a reader who wishes to remain anonymous (thanks!).

The Study: Dairy Fat Consumption and the Risk of Metabolic Syndrome: An Examination of the Saturated Fatty Acids in Dairy.  Allison L. Unger,Moises Torres-Gonzalez, and Jana Kraft.  Nutrients 2019, 11(9), 2200; https://doi.org/10.3390/nu11092200

The review argues: “it is likely that the diverse array of SFA [saturated fatty acid] constituents within full-fat dairy foods contributes to favorably modulating cardiometabolic health.”

It concludes: “In summary, previous work on the impact of dairy-derived SFA consumption on disease risk suggests that there is currently insufficient evidence to support current dietary guidelines which consolidate all dietary SFA into a single group of nutrients whose consumption should be reduced, regardless of dietary source, food matrix, and composition.”

Funding and Conflicted Interests (my emphasis): “The work involved for this manuscript was funded by National Dairy Council….M.T.-G. is employee of National Dairy Council. J.K. has received research funding from National Dairy Council.

Comment: This purpose of this dairy-funded review is to demonstrate that contrary to contradictory information, the saturated fatty acids in dairy foods are not only benign, but beneficial. The dairy industry would love that to be true.

This particular sponsored review is exceptionally well organized and illustrated.  I especially appreciated the timeline of dietary recommendations for saturated fat from 1977 to the present.  This is the bottom half:

This is a classic industry-funded review arriving at the desired conclusions.  In essence, it is a dairy industry advertisement and should be understood as such.

Why do this?  The dairy industry is in serious economic trouble these days, as I will discuss tomorrow.

The press release from the Annals of Internal Medicine arrived last week under embargo, sent to me by several reporters: “New guidelines: No need to reduce red or processed meat consumption for good health.”

The press announcement was accompanied by 5 review papers, a sixth with this recommendation, and an editorial.  These are posted on the website of their publisher, the American College of Physicians, implying this organization’s endorsement of this guideline.

Collectively, these papers challenge dietary advice to eat less processed meat and red meat on the grounds of inadequate science.

These papers argue:

• Eliminating processed and red meat from the diet may reduce disease risks but the effects are small and evidence for them is of low quality and low certainty.
• Omnivores are unwilling to eat less meat.
• If you continue to think eating meat is bad for you in the face of this evidence, you are a victim of the “the less you know, the more you hold to your beliefs” syndrome.
• You can ignore dietary guidelines (regardless of source) and continuing eating meat as you always have.

This is a good example of what I call nutritional nihilism, an approach that insists that because observational studies are based on self-reported information and necessarily flawed, their conclusions are unscientific and should be discounted.  Therefore, because we can’t do more rigorous studies, we should not advise the public about diets best for health or the environment.

I have several concerns about all this:

• Yes, the effects are small but that is true of nutrition studies in general.  The small effects show benefits from eating less meat.  The authors could easily have interpreted their work as suggesting that eating less meat might be useful.  This is an example of interpretation bias.
• The authors took a strictly science-based approach to a problem strongly affected by social, economic, and political factors and values.
• The studies look at previous studies that compared people who eat meat to those who eat less. The authors excluded studies of vegetarians compared to meat-eaters.
• They look at meat outside its context of calories.
• The authors did not look at the totality of the evidence; they excluded laboratory and animal studies that can be more closely controlled.
• They excluded studies of environmental impact, which has a significant bearing on human dietary practices (meat production adds more greenhouse gases than vegetable production).
• The conclusions fall into the category of “everything you thought you knew about nutrition is wrong.”  This rarely happens.  Science usually works incrementally, not in one enormous reversal like this.

Do the authors really believe that all those other committees and commissions urging less meat were wrong and continue to be wrong?   Their strictly science-based approach seems unrealistic.

The papers come across to me as a concerted attack on dietary guidelines (national and international), on nutrition science in general, and on nutritional epidemiology in particular.

The meat industry and its supporters will love them.

Attacks on the quality of nutrition research have been coming from many sources lately: the food industry, of course, but also statisticians (John Ioannidis at Stanford is making a career of this), and some scientists (usually with ties to food companies).  The criticisms themselves are not new.

What is new is the vehemence and level of effort to discredit observational studies, particularly those based on self-reports of dietary intake.  Yes, nutritional epidemiology has flaws, but the methods have been useful in many instances, as argued convincingly by two of its leading practitioners.

In looking at nutrition research, I think it is essential to evaluate the totality of information available: laboratory, animal, human epidemiology and clinical studies—and to do this in the context of what people actually eat and the number of calories they consume, as well as adding in a hefty dose of common sense.

Common sense is what’s missing in these studies.  Do the authors really believe that:

• Meat eaters are healthier than vegetarians?
• Eating more meat is better for health?
• Meat eaters are less obese and have less heart disease and cancer than those who eat less?

If not, the conclusions make no sense.

Most of the authors report no financial ties to the food industry.  I would love to know the back story about why they chose to do these studies and to interpret them in this way.

Reactions (I will be adding to this list as they come in)

• The Harvard School of Public Health Nutrition Department issued a statement
• The True Health Initiative (THI) issued a press release outlining its concerns (the link is here)
• THI council members sent a letter to the journal editor stating objections (the link)
• THI collected quotes from members of its council and others (including mine)
• THI also produced graphics.  Here is one example.

• David Katz weighs in
• New York Times: 5 things you should know
• New York Times coverage: “Eat less meat, scientists said.  Now some believe that was bad advice.”
• From Dean Ornish
• Consumer Reports (I’m quoted)
• From the World Cancer Research Fund
• Vox’s crystal clear explanation
• NPR’s The Salt’s excellent analysis
• Aaron Carroll’s follow-up to his editorial

These three papers were part of a supplement to Advances in Nutrition published in September 2019: Supplement—6th Yogurt in Nutrition Initiative (YINI) Summit / More than the Sum of Its Parts, sponsored by Danone Institutes International. Publication costs for this supplement were defrayed in part by the payment of page charges.

I.  Introduction to the Sixth Global Summit on the Health Effects of Yogurt: Yogurt, More than the Sum of Its Parts.  Sharon M Donovan ; Olivier Goulet. Advances in Nutrition, Volume 10, Issue 5, September 2019, Pages 913S–916S.

Conclusion: “Ultimately, the inclusion of fermented dairy products in food-based dietary guidelines, not only as a dairy option, but as a significant source of viable bacteria and fermentation products, could contribute to improved public health and should be considered.”

Author disclosures: “The guest editor of the supplement has the following conflict of interest: SMD co-chairs the Yogurt in Nutrition Initiative. She received reimbursement for travel expenses and an honorarium from Danone Institutes International for chairing the Sixth International Yogurt in Nutrition Summit at the Nutrition 2018 meeting in June 2018 in Boston, MA….SMD and OG are co-chairs of the Yogurt in Nutrition Initiative. Travel expenses and an honorarium were paid to SMD and OG by Danone Institutes International for chairing the Sixth International Yogurt in Nutrition Summit at the Nutrition 2018 meeting in June 2018 in Boston, MA. OG is also the Chair of Danone Institutes International.

II.  Dairy Foods, Obesity, and Metabolic Health: The Role of the Food Matrix Compared with Single Nutrients.  Dariush Mozaffarian.  Advances in Nutrition, Volume 10, Issue 5, September 2019, Pages 917S–923S,

Conclusion: “The present evidence suggests that whole-fat dairy foods do not cause weight gain, that overall dairy consumption increases lean body mass and reduces body fat, that yogurt consumption and probiotics reduce weight gain, that fermented dairy consumption including cheese is linked to lower CVD risk, and that yogurt, cheese, and even dairy fat may protect against type 2 diabetes. Based on the current science, dairy consumption is part of a healthy diet, without strong evidence to favor reduced-fat products; while intakes of probiotic-containing unsweetened and fermented dairy products such as yogurt and cheese appear especially beneficial.”

Disclosures: “DM received an honorarium from the American Society of Nutrition for the preparation of this manuscript. A freelance science writer, Denise Webb, was supported by Danone Institute International to prepare an initial draft of this manuscript for DM based on a recording of his talk and slides at the American Society of Nutrition 2018 Congress. The final manuscript was edited in detail and approved by DM. The funders had no role in the design, analysis, interpretation, review, or final approval of the manuscript for publication…DM reports research funding from the NIH and the Gates Foundation; personal fees from GOED, Nutrition Impact, Pollock Communications, Bunge, Indigo Agriculture, Amarin, Acasti Pharma, Cleveland Clinic Foundation, and America’s Test Kitchen; scientific advisory board, Elysium Health (with stock options), Omada Health, and DayTwo; and chapter royalties from UpToDate; all outside the submitted work.”

III.  Effects of Full-Fat and Fermented Dairy Products on Cardiometabolic Disease: Food Is More Than the Sum of Its Parts.  Arne Astrup; Nina Rica Wium Geiker; Faidon Magkos.  Advances in Nutrition, Volume 10, Issue 5, September 2019, Pages 917S–923S.

Conclusion: “Although more research is warranted to adjust for possible confounding factors and to better understand the mechanisms of action of dairy products on health outcomes, it becomes increasingly clear that the recommendation to restrict dietary saturated fat to reduce risk of cardiometabolic disease is getting outdated. Therefore, the suggestion to restrict or eliminate full-fat dairy from the diet may not be the optimal strategy for reducing cardiometabolic disease risk and should be re-evaluated in light of recent evidence.”

Disclosures.  “NRWG and FM, no conflicts of interest. AA is a member of advisory boards/consultant for BioCare Copenhagen, Denmark; Dutch Beer Institute, Netherlands; Gelesis, United States; Groupe Éthique et Santé, France; McCain Foods Limited, United States; Novo Nordisk, Denmark; Pfizer, United States; Saniona, Denmark; and Weight Watchers, United States. AA has received travel grants and honoraria as a speaker for a wide range of Danish and international consortia. AA is co-owner and member of the board of the consultancy company Dentacom Aps, Denmark; cofounder and co-owner of UCPH spin-outs Mobile Fitness A/S, Flaxslim ApS, and Personalized Weight Management Research Consortium ApS (Gluco-diet.dk). He is coinventor of a number of patents owned by the University of Copenhagen, in accordance with Danish law. He is coauthor of a number of diet and cookery books, including books on personalized diet approaches. AA is not an advocate or activist for specific diets and is not strongly committed to any specific diet.”

Comment

These papers aim to dispute the idea that full-fat dairy products but have negative health effects. This is a legitimate scientific question that deserves investigation and analysis, preferably by studies funded by independent sources.  Industry-funded studies and opinion pieces are well known to produce results and conclusions favorable to the sponsor’s interest, as is the case here.