Search results: american journal of clinical nutrition

I’ve collected five more studies funded directly or indirectly by food companies or trade associations, with results useful for marketing purposes.  This brings the total to 105 that I’ve noticed since last March versus only 9 with results that must have disappointed the sponsors.

Canned Vegetable and Fruit Consumption Is Associated with Changes in Nutrient Intake and Higher Diet Quality in Children and Adults: National Health and Nutrition Examination Survey 2001-2010.  Marjorie R. Freedman, PhD; Victor L. Fulgoni III, PhD.  J Acad Nutr Diet. 2015  http://dx.doi.org/10.1016/j.jand.2015.10.013.

• Conclusions: Results suggest CVþCF consumption was associated with higher intake of select nutrients, a higher-quality diet, and comparable adiposity measures and blood pressure.
• Funding for this project was received from the Canned Food Alliance.  As senior vice president at Nutrition Impact, LLC, V. L. Fulgoni III provides food and nutrition consulting and database analyses for various members of the food and beverage industry.  No potential conflict of interest was reported by M. R. Freedman.

Regular Fat and Reduced Fat Dairy Products Show Similar Associations with Markers of Adolescent Cardiometabolic Health.   O’Sullivan, T.A.; Bremner, A.P.; Mori, T.A., Beilin, L.J., Wilson, C., Hafekost, K., Ambrosini, G.L., Huang, R.C., Oddy, W.H..Nutrients 2016, 8, 22.

• Conclusion: Although regular fat dairy was associated with a slightly better cholesterol profile in boys, overall, intakes of both regular fat and reduced fat dairy products were associated with similar cardiometabolic associations in adolescents.
• Conflicts of Interest: Therese A. O’Sullivan received a grant from The Dairy Health and Nutrition Consortium Australia…which provided funding for the analysis and write up of this study. No other authors declare a conflict of interest.

Suboptimal Plasma Long Chain n-3 Concentrations are Common among Adults in the United States, NHANES 2003–2004. Rachel A. Murphy, Elaine A. Yu, Eric D. Ciappio, Saurabh Mehta and Michael I. McBurney   Nutrients 2015, 7, 10282–10289; doi:10.3390/nu7125534.

• Conclusion: Suboptimal LCn-3 [omega-3] concentrations are common among U.S. adults. These findings highlight the need to increase LCn-3 intake among Americans.
• Conflicts of Interest: M.I.M., E.D.C. and R.A.M. are employees of D.S.M. Nutritional Products, L.L.C., manufacturers and suppliers of omega-3 nutritional lipids. E.Y. and S.M. have no conflicts of interest to disclose.

Red Raspberries and Their Bioactive Polyphenols: Cardiometabolic and Neuronal Health Links.  Britt M Burton-Freeman, Amandeep K Sandhu, and  Indika Edirisinghe.  Adv Nutr January 2016 Adv Nutr vol. 7: 44-65, 2016. doi: 10.3945/​an.115.009639

• Conclusion: The body of research is growing and supports a potential role for red raspberries in reducing the risk of metabolically based chronic diseases.
• Funding: Supported in part by various donors and the National Processed Raspberry Council.

Dietary flavonoid intake and incidence of erectile dysfunction. Aedín Cassidy, Mary Franz, and Eric B Rimm.  American Journal of Clinical Nutrition. First published ahead of print January 13, 2016 as doi: 10.3945/ajcn.115.122010.

• Conclusions: These data suggest that a higher habitual intake of specific flavonoid-rich foods is associated with reduced ED incidence. Intervention trials are needed to further examine the impact of increasing intakes of commonly consumed flavonoid-rich foods on men’s health.
• Authors’ disclosure: AC and EBR received funding from the US Blueberry Highbush Council for a separate project unrelated to this publication.
• Comment: The University of East Anglia, where the lead author works, sent out a press release “Blueberries associated with reduced risk of erectile dysfunction.”

As regular readers know, I’ve been posting studies funded by food companies with results favorable to the companies’ interests whenever I run across five of them.   Since mid-March, I’ve posted 7 such collections for a total of 37 studies (two of the posts listed 6 studies).  These are all papers published since March.

With each set, I asked readers to send examples of studies that do not favor the sponsor’s interest.

They are rare, but do exist.  I’ve been sent two so far.  I’m guessing it will be a long time before I collect five, so have a look:

Butter increased total and LDL cholesterol compared with olive oil however resulted in higher HDL cholesterol than habitual diet. Sara Engel and Tine Tholstrup.  American Journal of Clinical Nutrition, July 1, 2015, doi: 10.3945/​ajcn.115.112227.

• Conclusions: Moderate intake of butter resulted in increases in total cholesterol and LDL cholesterol compared with the effects of olive oil intake and a habitual diet (run-in period). Furthermore, moderate butter intake was also followed by an increase in HDL cholesterol compared with the habitual diet. We conclude that hypercholesterolemic people should keep their consumption of butter to a minimum, whereas moderate butter intake may be considered part of the diet in the normocholesterolemic population.
• Sponsor: Danish Dairy Research Foundation
• Comment: The data clearly show that butter raises blood cholesterol levels.  The authors spin it as positively as possible—higher HDL and it’s OK for people with normal cholesterol to eat moderate amounts of butter—but they make the downside quite clear.  In this study, “moderate” butter means 4.5% of calories or just 2/3 of a tablespoon for someone eating 2000 calories.  That’s not much, alas.

Influence of Pistachios on Performance and Exercise-Induced Inflammation, Oxidative Stress, Immune Dysfunction, and Metabolite Shifts in Cyclists: A Randomized, Crossover Trial.  David C. Nieman, Johannes Scherr, Beibei Luo, Mary Pat Meaney, Didier Dréau, Wei Sha, Dustin A. Dew, Dru A. Henson, Kirk L. Pappan.  PLoS One, November 19, 2014. DOI: 10.1371/journal.pone.0113725

• Conclusion: In summary, 2-weeks pistachio nut ingestion was associated with reduced 75-km cycling time trial performance and increased post-exercise plasma levels of raffinose, sucrose, and metabolites related to leukotoxic effects and oxidative stress.
• Funder: This work was supported by American Pistachio Growers. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
• Comment:  It’s obvious that the funders had no role.  I’ll bet they are quite unhappy with the results.

This second study came out last year but I’ll take any of these I can get.  Please do send.

But if I’m just counting since March, the ratio is 37 studies favoring the sponsor’s interest, to 1 that doesn’t.  Coincidence?  I’m not convinced.

Despite my long interest in and dubious opinion about the benefits of Golden Rice (genetically modified to contain the beta-carotene precursor of vitamin A), I somehow completely missed the huge and highly embarrassing uproar over a study demonstrating the effectiveness of this rice in raising vitamin A levels in young children.

This particular uproar began with publication of the study in the American Journal of Clinical Nutrition in 2012.  Last week the journal announced that it has retracted the study—on ethical, not scientific, grounds.

To explain:  Dr. Guangwen Tang, a long-time researcher at Tufts University, and her colleagues at Tufts, in China, and at Baylor and the NIH, compared the effectiveness of vitamin A capsules, Golden Rice, and spinach in raising vitamin A levels in the blood of Chinese schoolchildren.  They reported that Golden Rice proved just as effective as capsules, and somewhat better than spinach, in inducing higher vitamin A levels, just as it is supposed to do.

Golden Rice, of course, is the poster child for the benefits of GMOs, extolled by many as the solution to the developing world’s high prevalence of vitamin A deficiency (I’m dubious because I view vitamin A deficiency as a social problem requiring policy and cultural shifts).

Soon after, Greenpeace, which is decidedly anti-GMO, challenged the ethics of the study, charging that the children were being used as “guinea pigs.”

As reported in Nature,

none of the children, their parents or school teachers was aware that Golden Rice was involved, according to a 45-minute investigative news programme broadcast on 8 December on CCTV, China’s state television channel.  The informed-consent form said that the rice contained β-carotene, but not that it was genetically modified or that it was Golden Rice. Nor did it highlight uncertainty around any potential risks of ingesting such rice…Moreover, Wang didn’t apply for ethical evaluation of the trial, instead fabricating the approval documents, according to CDC. And Tang brought Golden Rice from the United States to China illegally, without due declaration to the relevant Chinese authorities, it said.

According to a report on NPR, Tufts University did a year-long investigation and agreed that ethical standards had been violated:

the study was not “conducted in full compliance with … policy or federal regulations”… the researchers did not adequately explain the nature of golden rice and made some changes in the study without getting approval from the committee at Tufts that is supposed to review all research involving human subjects.  Guangwen Tang will be banned from conducting research on human subjects for two years. For two years after that, any research that she conducts will be under the direct supervision of another investigator.

A report on the case in ScienceInsider explains the ethical problem raised by the study’s informed consent form :

U.S. guidelines stipulate that such forms use plain language understandable to lay people, and the IRB [the Tufts Institutional Review Board] agreed to let Tang say that “Golden Rice is a new rice which makes beta-carotene,” without using the loaded words “genetically modified.” (The consent form for a very similar study by Tang among adults in Boston, published in 2009, didn’t use that term either.) Given the sensitivities over transgenic food, which existed in China as well, that was the wrong decision, according to the external panel.

In 2014,  Dr. Tang sued the ASN:

ASN twice asked Tang and her six co-authors to withdraw the paper voluntarily, which they declined to do. The society recently decided to retract the paper on its own…but it has agreed to a 90-day stay after Tang filed her lawsuit, to see if the matter can be settled out of court.

But the court ruled in favor of ASN.  Hence, the retraction.  ASN issued a press release:

In a ruling by the Massachusetts Superior Court, Judge Salinger…cleared the way for the American Society for Nutrition (ASN) to retract the article “β-Carotene in Golden Rice is as good as β-carotene in oil at providing vitamin A to children”…ASN is very pleased that the Massachusetts courts have upheld the organization’s First Amendment rights and have allowed ASN to move forward with the retraction of the article.

In its online retraction notice, ASN states the reasons:

1. The authors are unable to provide sufficient evidence that the study had been reviewed and approved by a local ethics committee in China in a manner fully consistent with NIH guidelines….
2. The authors are unable to substantiate through documentary evidence that all parents or children involved in the study were provided with the full consent form for the study.
3. Specific eligibility issues were identified in regard to 2 subjects in the study.

Last week, Retraction Watch published a lengthy summary of this case that includes a long statement from Tufts University:

No questions were raised about the integrity of the study data, accuracy of the research results or safety of the research subjects…Tufts University has always been and remains deeply committed to the highest ethical and scientific standards in research.  In September 2012, w …convened an external review committee to interview those involved and to review documentation of the study…There was no evidence found of falsification or fabrication of the data that underlie the study’s primary findings. Those reviews did, however, determine that the research had not been conducted in full compliance with Tufts research policies and federal research regulations.

The retraction is a huge embarrassment, not only for the researchers involved but also for Tufts University’s Friedman School of Nutrition Science and Policy, Tufts’ Institutional Review Board, the American Journal of Clinical Nutrition, and the American Society for Clinical Nutrition.

The study was funded by NIH, USDA, as well as a program in China.  NIH takes research ethics very seriously and expects the researchers it funds to adhere to the highest possible standards for research on human subjects.  Because the study did not follow standard ethical guidelines, especially with regard to research on children, Tufts had no choice but to investigate and impose sanctions, and the journal had no choice but to retract the paper.

This case reinforces my views about GMOs in general and Golden Rice in particular.

The controversies are not (or not usually) about the science.  They are very much about ethics and other questions of values.

I’ve been posting summaries of studies funded by food companies or trade groups, all of which come up with results that the sponsor can use for marketing purposes.

In each of these posts, I ask for examples of industry-funded studies that produce results contrary to the interests of the funder.

In response, I received this comment from Mickey Rubin, Vice President for Nutrition Research, National Dairy Council.

He gave me permission to reproduce his letter: 

Dear Marion,

By way of introduction, my name is Mickey Rubin and I am a scientist at the National Dairy Council. I understand that you know Greg Miller, and I asked him for your contact information so I could write to you directly after reading with great interest your most recent post on industry-funded nutrition research, in which you selected a sample of 5 studies/papers sponsored by industry all showing favorable outcomes. Although none of the papers you selected were sponsored by the organization I represent (although there is one dairy industry sponsored review paper in the list), what struck me is your focus on the favorable vs. unfavorable dichotomy, rather than the reality of what much nutrition science research results in: null findings.

It seems that there are fewer and fewer nutrition studies published that report the null, or find no effect. I agree with you that the reason we don’t see more of these studies in the literature has to do with bias, but I suspect that it is publication bias as much as any other bias. From my interactions with nutrition researchers, I gather it is quite difficult and sometimes impossible to get a study with no significant effects published regardless of funding source, to say nothing of allegiance bias by some researchers hesitant to publish findings that may go against their own hypotheses. Dr. Dennis Bier of Baylor College of Medicine and editor in chief of the American Journal of Clinical Nutrition has presented eloquently on this issue previously. You may also be aware of David Allison’s papers on other types of bias. So I think it is important to discuss all types of bias, and not just industry bias. You of course wouldn’t want your discussion on bias to be biased to just one type.

At National Dairy Council we have an extensive program of nutrition research that we sponsor at universities both nationally and internationally. While I can’t speak for all of industry, we strongly encourage the investigators of all of our sponsored studies to publish the findings, no matter the results. Thus, we would expect our sponsored studies to have a similar “success” rate as those sponsored by the National Institutes of Health. In fact, that is exactly what one recent analysis – not sponsored by the dairy industry – found, reporting that there was no evidence that dairy industry funded projects were more likely to support an obesity prevention benefit from dairy consumption than studies sponsored by NIH.

We feel this transparency is not only critical to the credibility of the research we sponsor, but we also feel it is important that our research contributes to nutrition science knowledge as a whole. We hope that other scientists take the findings from studies we sponsor and build upon them, and if it is by using research dollars from other sources, even better! I’ll be the first to stand up and say that one favorable study on milk, as an example, does not close the books on the subject. We need many studies in many different labs sponsored by multiple agencies in order to produce a portfolio of knowledge. I suspect that is certainly an example of where you and I are in agreement.

That all said, please allow me to provide some examples of studies the National Dairy Council has sponsored that are published and, rather than showing a clear benefit, do not refute the null hypothesis. These are all studies published within the last 4 years. It’s not meant to be comprehensive, but rather just a sample similar to what you provided. I could also provide you a list of studies we have sponsored that have shown favorable results for dairy, but you seem to have that covered, and I’ll instead wait until one of our sponsored studies appears in a subsequent blog post J.

Thanks for taking the time to read. I appreciate the dialogue.

Here’s his list of papers:

Studies with null finding:

Bendtsen et al. 2014: http://www.ncbi.nlm.nih.gov/pubmed/24168904

• No unique benefit of dairy protein over other proteins for weight maintenance

Maki et al. 2013: http://www.ncbi.nlm.nih.gov/pubmed/23901280

• No effect of three servings of dairy on blood pressure

Chale et al. 2013: http://www.ncbi.nlm.nih.gov/pubmed/23114462

• Whey protein supplementation offered no additional benefit over resistance training alone in older individuals

Lambourne et al. 2013: http://www.ncbi.nlm.nih.gov/pubmed/23239680

• No change in body weight or composition in adolescents performing resistance training and supplemented with milk, juice, or control

Van Loan et al. 2011: http://www.ncbi.nlm.nih.gov/pubmed/21941636

• Recommended dairy servings offered no additional weight loss benefit over calorie restriction without dairy servings 

Studies with mixed findings (some outcomes changed, others null):

Maki et al. 2015: http://www.ncbi.nlm.nih.gov/pubmed/25733460

• The main finding from the study was that dairy intake had no effect on glucose control whereas sugar sweetened product consumption contributed to a worsening of glucose control in at-risk adults.

Dugan et al. 2014: http://www.ncbi.nlm.nih.gov/pubmed/24236646

• Waist circumference and BMI were lower in women after consuming the dairy diet as compared to the control diet. Fasting glucose was lower in men following the dairy diet as compared to the control diet. There were no differences in blood pressure, serum lipids, fasting insulin, or insulin resistance between the treatments.

Here’s what I wrote in response:

I am familiar with charges of bias against independently funded researchers (“White-hat Bias”), which equates industry biases with biases that result from career objectives and other goals.  I do not view the biases as equivalent.  Industry-sponsored research has only one purpose: to be used in marketing to sell products.   As I have said repeatedly, it is easy to design studies that produce desired answers.

When I was in graduate school in molecular biology, we were taught—no, had beaten into us—to do everything we could to control for biases introduced by wishful thinking.  I don’t see that level of critical thinking in most studies funded by food companies.

You may be correct about the influence of publication bias with respect to dairy studies, but how do you explain the situation with sugar-sweetened beverages?  Studies funded by government and foundations typically indicate strong correlations between habitual consumption of sugary beverages and metabolic problems, whereas studies funded by the soda industry most definitely do not.   The percentages are too high to be due to chance: 90% of independently funded studies show health effects of soda consumption whereas 90% of studies funded by soda companies do not.  This is troubling.

We’ve seen the results of studies funded by tobacco and drug companies.  Are food-industry studies different?  I don’t think so.   What seems clear is that industry-induced biases are not recognized by funding recipients, a problem in itself.

That’s why I’m posting these studies as they come in and begging for examples of industry-funded studies that do not favor the interests of the donor.

Thanks to Mickey Rubin for writing and for permission to reproduce his letter.

Let the discussion continue!

Here is my latest roundup of industry-sponsored research producing results or opinions that favor the sponsor’s commercial interests.

Sugars and obesity: Is it the sugars or the calories?  Choo FL, Ha V, Sievenpiper JL.  Nutrition Bulletin, May 19, 2015.  DOI: 10.1111/nbu.12137

Conclusion: The higher level evidence reviewed in this report does not support concerns linking fructose-containing sugars with overweight and obesity.

Conflicts of interest: All three authors report scholarship or research support from such entities as the Canadian
Sugar Institute, PepsiCo, Coca-Cola, Dr Pepper Sapple, Corn Refiners Association, World Sugar Research Organization.

Cranberry Juice Consumption Lowers Markers of Cardiometabolic Risk, Including Blood Pressure and Circulating C-Reactive Protein, Triglyceride, and Glucose Concentrations in Adults.  Janet A Novotny, David J Baer, Christina Khoo, Sarah K Gebauer, and Craig S Charron. J. Nutr. 2015; 145:1185-1193 doi:10.3945/jn.114.203190.

Conclusion: LCCJ [low-calorie cranberry juice] can improve several risk factors of CVD [cardiovascular disease] in adults, including circulating TGs [triglycerides], CRP (c-reactive protein], and glucose, insulin resistance, and diastolic BP [blood pressure].

Sponsor: Ocean Spray Cranberries, Inc. and the USDA.  JA Novotny received funding from  and C Khoo is employed by Ocean Spray Cranberries, Inc.

Effect of cheese consumption on blood lipids: a systematic review and meta-analysis of randomized controlled trials. Janette de Goede, Johanna M. Geleijnse, Eric L. Ding, and Sabita S. Soedamah-Muthu

Conclusion: Despite the similar P/S ratios of hard cheese and butter, consumption of hard cheese lowers LDL-C and HDL-C when compared with consumption of butter.

Funding. The senior author received unrestricted research grants from the Global Dairy Platform, the Dairy Research Institute, and Dairy Australia for the present meta-analysis. One other author, E.L.D., has consulted for the Dairy Research Institute.

Protein Summit 2.0: Evaluating the Role of Protein in Public Health: Proceedings of a conference held in Washington, DC, October 2, 2013.  American Journal of Clinical Nutrition, June 2015 Supplement.

Program organizer: Shalene McNeill, National Cattlemen’s Beef Association, and a Contractor to The Beef Checkoff.

Sponsors: The Beef Checkoff, Dairy Research Institute, Egg Nutrition Center, Global Dairy Platform, Hillshire Brands, National Pork Board

My comment: Journal supplements are typically paid for by outside parties—government agencies, foundations, private organizations, or food companies.  The papers in this supplement discuss various aspects of protein and health.  All emphasize the benefits of animal protein in human diets, as might be expected, given the sponsors.

Two examples:

Commonly consumed protein foods contribute to nutrient intake, diet quality, and nutrient adequacy.  Stuart M Phillips, Victor L Fulgoni III, Robert P Heaney, Theresa A Nicklas, Joanne L Slavin, and Connie M Weaver.  Am J Clin Nutr June 2015 vol. 101 no. 6 1346S-1352S.

Conclusion: dietary recommendations to reduce intakes of saturated fat and solid fats may result in dietary guidance to reduce intakes of commonly consumed food sources of protein, in particular animal-based protein.

The role of protein in weight loss and maintenance.  Heather J Leidy, Peter M Clifton, Arne Astrup, Thomas P Wycherley, Margriet S Westerterp-Plantenga, Natalie D Luscombe-Marsh, Stephen C Woods, and Richard D Mattes.

Conclusion:  Collectively, these data suggest that higher-protein diets…provide improvements in appetite, body weight management, cardiometabolic risk factors, or all of these health outcomes.

For the record: Industry sponsorship does not necessarily mean that the reported conclusions are wrong.  It just means that the papers require even more than the usual level of critical analysis.

I am happy to post industry-sponsored studies that do not produce results that can be used to market the sponsor’s products.  Please send if you find any.

I like the special editions of the business newsletter, FoodNavigator USA.  This especially big one collects its recent articles on sodium reduction—a big issue these days.   These give a good idea of how food companies are dealing with pressures to lower their salt content.

It’s expensive, risky, and difficult, but manufacturers have made huge progress on sodium reduction in recent years. But how much further can they go, and where is the return on investment if consumers are at best indifferent to their efforts, or at worst downright suspicious?

This special edition explores the challenges of sodium reduction, and asks whether it’s falling down the food policy agenda in the US, but also provides examples of creative solutions that can help manufacturers reduce it without compromising on taste or functionality.

Is sodium reduction falling down the food policy agenda?  Four years ago sodium was public enemy #1. The Institute of Medicine (IOM) was calling for the FDA to modify the GRAS status of salt and slash the daily value for sodium to 1,500mg, and the food industry was on high alert. Today, sugar is the new bogeyman, and while sodium intakes remain stubbornly high, the FDA has yet to issue voluntary guidelines. So is sodium reduction falling down the food policy agenda?

AHA education campaign pressures food manufacturers to reduce sodium: The American Heart Association says its recently launched consumer education campaign encouraging Americans to “break up with excess salt” seeks to “build an army of passionate and willing supporters” to pressure food manufacturers to reduce sodium in packaged foods.

Advanced technology eases sodium reduction efforts: Advances in technology can help firms more quickly and easily reduce sodium in breads and grain-based packaged foods – a previously repetitive and expensive trial and error process, according to Janice Johnson, food applications leader in salt at Cargill.

Will proposals to mandate potassium labeling on the Nutrition Facts panel give potassium-chloride based sodiumreplacers a shot in the arm?  Some food manufacturers still worry that using potassium chloride to replace salt in their recipes might compromise their clean label credentials. But the FDA’s recent proposal to include potassium as one of the nutrients that must be listed on the Nutrition Facts panel is helping to change that mindset, says NuTek Salt.

Sodium reduction: has all the low-hanging fruit been plucked?  Food manufacturers are under increasing pressure to reduce sodium, but surveys suggest many shoppers are, well, not that bothered. So where does this leave firms plugging sodium reduction solutions?

Reformulation by stealth: Just 2% of new launches in salty snacks make overt sodium reduction claims: The vast majority of sodium reduction activity in the US food industry is now being conducted by ‘stealth’ in order to avoid alienating shoppers, according to Tate & Lyle.

Industry to FDA: Think again before setting category-by-category sodium reduction targets.  Two leading food industry associations have urged the Food and Drug Administration (FDA) not to set category-by-category limits for sodium amid rumors that the agency is planning to outline a new sodium reduction strategy this year.

Can seaweed become the ultimate salt replacer – and why hasn’t it yet?  Seaweed is well-researched, sustainable and effective, according to an expert. So what is stopping it from really taking off as a salt replacer?

Mandatory salt reduction could save more in healthcare costs: Study.  Mandatory salt reduction may save more in healthcare costs than the current voluntary system, say the authors of a study published in Value in Health.

Myth busting? High salt intake may not increase thirst:  It is commonly believed that consumption of salty foods increases thirst, and could be a reason for increased consumption of sugary soft drinks and alcoholic beverages. But just how true is this notion?

Are salt reduction efforts reflected in heart health?  Salt reduction efforts around the world are making progress – but how has lower salt consumption affected health?

Salt substitutes help reduce blood pressure.  Efforts to reduce consumer blood pressure and risk of hypertension by replacing normal salt with blends of potassium chloride, magnesium sulfate and less sodium chloride are working, but may be more effective in countries where the majority of salt comes from home cooking, according to a meta-analysis in the December American Journal of Clinical Nutrition.

‘Quiet’ salt reduction is vital – but gourmet salt growth may stifle industry efforts.  Salt replacer use is growing but low salt claims are not, as food companies favour a ‘quiet’ approach – but growth in gourmet table salts may threaten salt reduction efforts.

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When the FDA advisory came out a week or so ago, I started getting questions about whether it meant that women must eat fish during pregnancy and, if so, how much.

As I said in my previous post on the topic, if you like fish, of course eat it, otherwise I can’t think of any compelling reason why anyone has to eat fish.

I view the data on the dilemma caused by omega-3 fatty acids in fish (good) versus the content of methylmercury (bad) as still rather uncertain.  Dr. Malden Nesheim and I discussed this point in an editorial we wrote for the American Journal of Clinical Nutrition [reference 1 below].

Here’s what the FDA advisory says:

Eat 8 to 12 ounces of a variety of fish each week from choices that are lower in mercury. The nutritional value of fish is important during growth and development before birth, in early infancy for breastfed infants, and in childhood… Fish contains important nutrients for developing fetuses, infants who are breastfed, and young children. Fish provides health benefits for the general public. Many people do not currently eat the recommended amount of fish.

This is a prescriptive statement telling pregnant women that they should eat fish.

I would argue that the data on which FDA based this prescription are limited, especially because the results of its scientific assessment are based mostly on theoretical models rather than empirical studies.

Here’s what makes me think some skepticism is warranted:

1. The effects of even low-level methylmercury exposure may be greater than discussed in the assessment [see reference 2], as the latest analysis from the Environmental Working Group explains.
2. The increase in young children’s IQ associated with fish-eating during pregnancy is low—-0.7 to a maximum of 3 IQ points.

As the FDA’s assessment report says:

On a population basis, average neurodevelopment in this country is estimated to benefit by nearly 0.7 of an IQ point (95% C.I. of 0.39 – 1.37 IQ points) from maternal consumption of commercial fish. For comparison purposes, the average population-level benefit for early age verbal development is equivalent in size to 1.02 of an IQ point (95% C.I. of 0.44 – 2.01 IQ size equivalence). For a sensitive endpoint as estimated by tests of later age verbal development, the average population-level benefit from fish consumption is estimated to be 1.41 verbal IQ points (0.91, 2.00). The assessment also estimates that a mean maximum improvement of about three IQ points is possible from fish consumption, depending on the types and amounts of fish consumed.

How significant is this?  And does the small benefit in childhood persist into adolescence or adulthood?

3. The economic question.  Fish are expensive.
4. The ecological questions.  Advice to increase fish consumption comes up against environmental realities—-overfishing, fish farming—-that make the recommendation impossibly unsustainable [reference 3].

• The levels of long-chain omega-3s in farmed fish depend on feeding them wild fish, an ecological problem on its own.
• Guidance about fish can’t be just nutritional; it has to take the economic and ecological impact of fish choices into consideration [reference 4].
• Current per capita fish consumption is about half the FDA recommended level, and half of that is shrimp.  Fortunately, shrimp don’t have much mercury (although the ones from Asia may have other contaminants), but they also don’t have much omega-3).

All of this suggests grounds for skepticism.  I think a better recommendation would leave more wiggle room to account for uncertainties.  Here’s how I would edit the FDA’s statement:

Pregnant women may eat up to 8 to 12 ounces of a variety of fish each week from choices that are lower in mercury.  Fish are useful sources of nutrients that may have value for growth and development before birth, in early infancy for breastfed infants, and in childhood, and may provide health benefits for the general public.  Other food sources also provide such benefits.

References

[1] Nesheim MC, Nestle M. Advice for fish consumption: challenging dilemmas. American Journal of Clinical Nutrition. 2014;99:973-974.

[2] Karagas MR, Choi AL, Oken E, Horvat M, Schoeny R, Kamai E, Cowell W, Grandjean P, Korrick S. Evidence on the human health effects of low-level methymercury  exposure. Environ Health Perspect. 2012; 120:799-806.

[3] Jenkins D, Sievenpiper JL, Pauli D, Sumaila UR, Kendall CWC  Are dietary recommendations for use of fish oils sustainable? Canadian Medical Association Journal 2009;180: 633-637.

[4] Oken E, Choi AL Karagas MR, Marien K, Rheinberger CM, Schoeny R, Sunderland E, Korrick S  Which fish should I eat? Perspectives influencing fish consumption choices. Environmental Health Perspectives 2012;120:790-798.

Mal Nesheim and I have an editorial in a recent issue of the American Journal of Clinical Nutrition: “Advice for fish consumption: challenging dilemmas.”

We commented on a research article evaluating blood mercury levels in adults eating seafood.

In it, we point out that

the 2010 Dietary Guidelines for Americans advise Americans to consume 8 ounces (227 g) of seafood per week to reach an average intake of 250 mg/d of the omega-3 fatty acids EPA and DHA.

This recommendation represents a substantial increase over current consumption amounts of ∼3.5 oz/wk. It is based on “moderate, consistent evidence” that the health benefits of increased seafood consumption outweigh the risks associated with methylmercury, a toxic contaminant of large predatory food fish (tilefish, shark, swordfish, king mackerel) and, to a lesser extent, albacore (white) tuna.

To avoid this toxin, the guidelines advise eating seafood typically found to be low in methylmercury, such as salmon, anchovies, sardines, and trout.

Such advice, however, leads to at least 3 dilemmas. Eating more fish might raise methylmercury intake above safe amounts. Pressures to consume more fish might place impossible demands on an already threatened seafood supply. And the obvious solution—fish farming—raises concerns about what farmed fish are fed and how farmed fish affects the environment.

We urge the 2015 Dietary Guidelines committee to take all this into consideration when making recommendations about fish consumption: “We hope that its advice for seafood consumption will help a confused public resolve some of these dilemmas and make wise seafood choices.”

Wise seafood choices may be an oxymoron, alas.