by Marion Nestle

Currently browsing posts about: Sponsored-research

May 8 2023

Industry-funded study of the week: Pasta!

Thanks to reader Thijs van Rens for sending this one, and apologies for the delay in getting to it.

This one comes from The Conversation back in January: Stop hating on pasta – it actually has a healthy ratio of carbs, protein and fat.

Its author writes about the benefits of pasta.

The ratio of carbs to protein in pasta is 38g to 7.7g, which equates to roughly a 5:1 ratio, well within the acceptable macronutrient distribution range. Meaning pasta actually has enough protein to balance with the carbohydrates…But pasta…also has micronutrients.

One cup of cooked pasta has about a quarter of our daily recommended intakes of vitamins B1 and B9, half the recommended intake of selenium, and 10% of our iron needs.

The news for pasta gets even better when we eat it as leftovers. When pasta is cooked and cooled, some of the carbohydrates convert to resistant starch. This starch gets its name from being resistant to digestion, so it contributes less energy and is better for blood sugar levels.

Funding: The author reports having “received funding for research or consulting from Mars Foods, Nutrition Research Australia, NHMRC, ARC, AMP Foundation, Kellogg, and the University of Newcastle.

Her article refers to: A systematic review on the relations between pasta consumption and cardio-metabolic risk factors.

Conclusion: Pasta meals have significantly lower postprandial glucose response than bread or potato meals,

Funding: American Heart Association, National Institute of Health, Barilla [the pasta maker!].

Comment

I love pasta, in moderation of course and with something this caloric, moderation is useful.  What’s going on here is a defense against rapidly absorbable carbohydrates which quickly convert to sugars.  I don’t necessarily disagree with the facts here; it’s the industry-funded distraction from calories that troubles.  It’s good that the authors disclosed their industry connections.

Apr 24 2023

Industry-funded study of the week: blueberries and menopause

NutraIngredients, a newsletter I read daily, caught my eye with this headline:

Blueberries benefit postmenopausal women with high blood pressure: Study:  Daily blueberry consumption improves endothelial function in postmenopausal women with high blood pressure, according to a recent study…. Read more

I looked it up, of course.

  • The study: Daily blueberry consumption for 12 weeks improves endothelial function in postmenopausal women with above-normal blood pressure through reductions in oxidative stress: a randomized controlled trial. Food Funct., 2023,14, 2621-2641
  • Objective: “to examine the efficacy of blueberries to improve endothelial function and blood pressure in postmenopausal women with above-normal blood pressure, and to identify potential mechanisms for improvements in endothelial function.”
  • Method: Postmenopausal women with elevated blood pressure or hypertension were given 22 g/day of freeze-dried highbush blueberry powder or placebo powder for 12 weeks.
  • Findings: The sum of plasma (poly)phenol metabolites increased in the blueberry group compared to baseline, and were higher than the placebo group.  Increases in several plasma flavonoid and microbial metabolites were also noted. No major differences were found for blood pressure, arterial stiffness, blood biomarkers, or endothelial cell protein expression following blueberry consumption (my emphasis).
  • Conclusion: “These findings suggest daily consumption of freeze-dried blueberry powder for 12 weeks improves endothelial function through reduced oxidative stress in postmenopausal women with above-normal blood pressure”
  • Conflicts of interest: There are no conflicts to declare.
  • Acknowledgements: This research was funded by the US Highbush Blueberry Council, the USDA National Institute of Food and Agriculture [Grant No. 2020-67017-30833/Project Accession No. 1021875], and the College of Health and Human Sciences at Colorado State University.

Comment: Yes there is a conflict of interest, but the authors don’t seem to recognize it.  This is a classic case of interpretation bias; the study didn’t show much of anything but the authors conclude that blueberry powder does some good.

High marks to NutraIngredients for disclosing the funding source right at the top of the article:

Published in the journal Food and Function, the study was supported by the US Highbush Blueberry Council and the USDA National Institute of Food and Agriculture.

 

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Apr 17 2023

Industry-funded study of the week: whey and muscle strength

I give high praise to NutraIngredients.com for doing full disclosure in the title of an article: “Industry study concludes whey promotes muscular strength and endurance, independent of diet.”

Whey protein supplementation promotes muscle mass increase and selective increases in muscular strength and endurance from resistance exercise, independent of dietary influence, according to a new industry-funded study.

I looked up the study.

The Study: Effects of Whey Protein Supplement on 4-Week Resistance Exercise-Induced Improvements in Muscle Mass and Isokinetic Muscular Function under Dietary ControlChae-Been Kim Jong-Hoon Park Hyoung-Su Park 2Hye-Jin Kim 2Jung-Jun Park   Nutrients.  2023 Feb 16;15(4):1003.   doi: 10.3390/nu15041003.
Purpose: to investigate the effect of whey protein supplementation under dietary control on improvements in muscle mass and function following resistance exercise training.
Method: Thirty-two men were randomly assigned to a whey protein supplementation group taking whey protein isolate (PSG, n = 17) and a placebo group (CON, n = 15). Participants were provided with three meals per day corresponding to the estimated individual daily energy intake. The supervised resistance exercise program was conducted 60 min per day, six days per week, for four weeks.
Conclusion: whey protein supplementation enhances resistance exercise-induced increase in muscle mass and overall muscular strength and endurance, independent of dietary influence.
Funding: This research was funded by Maeil Health Nutrition Co., Ltd.
Conflicts of Interest: The authors declare no conflict of interest.
Comment:  Maeil Health Nutrition is a Korean company which makes and sells dairy-based sports supplements like the one used in this study.  Two of the authors (the ones with 2 ) work for this company.  They have obvious conflicts of interest.  
I won’t bother to dissect the details of the study except to note that the placebo group was taking a supplement with 20 fewer grams of protein per day.
Apr 3 2023

Industry-funded study of the week: again, potatoes

The potato industry is hard at work funding studies to relieve any anxiety you might have about eating potatoes.  For the record, I think they are delicious in almost any form.  In moderation, of course.

Two items.

I.  A press release from the Idaho Potato Commission:Idaho Potatoes Are First Vegetable to Participate in American Diabetes Association Better Choices for Life Program.

The purpose of the partnership is to help educate tens of millions of Americans on ways they can add Idaho potatoes to their meal plan.

Diabetes is one of the country’s greatest health crises…With a mission to prevent and cure diabetes and improve the lives of all people affected by diabetes, the number one question the ADA receives is, what can I eat? Many wrongly believe they cannot eat potatoes.

“We want those living with diabetes and prediabetes to feel confident eating potatoes with their breakfast, lunch or dinner as long as serving size and preparation recommendations are followed,” explained Jamey Higham, President & CEO, IPC.”

Comment: You can’t make up this stuff.

II.  A funded study.  Several readers sent me this one:

The study: Rebello CJ, et al.  Low-Energy Dense Potato- and Bean-Based Diets Reduce Body Weight and Insulin Resistance: A Randomized, Feeding, Equivalence Trial .  Journal of Medicinal Food.  2022;25(12). https://doi-org.proxy.library.nyu.edu/10.1089/jmf.2022.0072

Conclusion: “Potato and Bean diets low in energy density were equally effective in reducing insulin resistance and promoting weight loss in individuals with impaired blood glucose control.”

Funding: “This work was supported in part by an investigator-initiated grant from the Alliance for Potato Research and Education …The funders (Alliance for Potato Research and Education and the National Institutes of Health) had no role in the design, analysis, or writing of this article. The content is solely the responsibility of the authors and does not necessarily represent the official views of the sponsors or the National Institutes of Health.

Comment: The point of this study is to demonstrate that potatoes do not, as many believe, raise insulin and blood sugar levels.

The authors of the paper say: “We demonstrated that contrary to observations from epidemiological studies, potatoes do not adversely affect the glycemic response.”

But look at how the investigators prepared the potatoes: “To enhance resistance to starch and dietary fiber components, the potatoes were boiled with skins, refrigerated for 12 to 24 h before the whole potato was incorporated into the meals.”

That’s one way to reduce the blood sugar response to potatoes.  It works!

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Mar 27 2023

Industry-funded study of the week: Strawberries

It feels like spring (at last!) in New York so I’m thinking about strawberries.

Last September, Lisa Young sent me a copy of an email she had received from a public relations agency.

Good Morning –

Today is World Alzheimer’s Day and a new study has found that eating Strawberries may reduce the risk of Alzheimer’s Disease and related dementias.

In fact, the compounds that give strawberries their beautiful red color may have several health benefits, such as lowering the risk of heart disease and some cancers and improving blood sugar control. And now researchers have found that one of those compounds, known as pelargonidin, may slow or prevent the development of Alzheimer’s Disease by lowering the number of twisted fibers inside the brain that contain a protein called tau. These twisted fibers are a hallmark of Alzheimer’s Disease.

The new study, which was supported by the National Institute of Aging and the California Strawberry Commission, was conducted postmortem on the brains of participants of the Rush Memory and Aging Project (MAP). Participants with the highest level of pelargonidin intake prior to their death also had less buildup in the brain of protein fragments called amyloid beta plaques – another hallmark of Alzheimers Disease. Pelargonidin is primarily found in berries. In this study, strawberries were the principal source of pelargonidin….

The study: Agarwal P, Holland TM, James BD, Cherian LJ, Aggarwal NT, Leurgans SE, Bennett DA, Schneider JA. Pelargonidin and Berry Intake Association with Alzheimer’s Disease Neuropathology: A Community-Based Study. J Alzheimers Dis. 2022;88(2):653-661. doi: 10.3233/JAD-215600. PMID: 35694918.

Results: “participants in the highest quartile of pelargonidin intake when compared to those in the lowest quartile, had less amyloid-β load (β (SE) = -0.293 (0.14), p = 0.038), and fewer phosphorylated tau tangles…”

Conclusion: “Higher intake of pelargonidin, a bioactive present in strawberries, is associated with less AD neuropathology, primarily phosphorylated tau tangles.”

Comment: I love strawberries and grow them in pots on my terrace.  But this study?  It looks at one chemical among many in strawberries and associates it with improved symptoms.  Association, alas, does not indicate causation.  If you give this a moment’s thought, could you believe that eating a few strawberries every day would help you prevent Alzheimer’s?  I’m all for plant-based diets.  And I’m all for eating strawberries.  But to imply that strawberries alone can control hunger, be good for your heart, especially if they come from California (as the Commission says on its website), seems a bit much.

Are strawberries demonstrably better for Alzheimer’s than any other berry or fruit?  The California Strawberry Commission is not interested in asking comparative questions.  It just wants you to buy more strawberries.

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Mar 20 2023

Industry-funded studies: null results!

I’m often saying that industry-funded studies tend to produce results that favor the funder’s commercial interests.  This is true, but there are occasional exceptions.

Here, for example, are two studies based on grants from the American Pistachio Growers to the same group of investigators.  Both are randomized clinical trials with results that must have disappointed the funder.

I. Effects of short-term pistachio consumption before and throughout recovery from an intense exercise bout on cardiometabolic markers

Results: Two weeks of pistachio consumption failed to elicit changes in any biomarker (p < .05).. .Overall, in healthy young men with normal blood lipid and glucose metabolism, little effect of either pistachios or intense exercise on cardiometabolic risk indicators was detected.

II. Influence of pistachios on force production, subjective ratings of pain, and oxidative stress following exercise-induced muscle damage in moderately trained athletes: A randomized, crossover trial.

Results: Creatine kinase, myoglobin, and C-reactive protein increased over time following exercise (p < 0.05); however, there were no advantages following pistachio consumption. No significant changes in vertical jump or superoxide dismutase were elicited during any trial.

Comment:  The second paper put a positive spin on the basically null results: “This study demonstrates that 3.0 oz/d of pistachios can reduce delayed onset of muscle soreness and maintain muscle strength, potentially promoting exercise tolerance and training adaptations.”  My question is why anyone would think that pistachios would make any difference anyway.  They are one food in the diets of people who eat many othere kinds of foods.  I’m all for eating pistachios, if you like them, along with lots of other healthy foods.  There is only one reason to do this kind of one-food research—for marketing purposes.

You don’t believe this?  Check out the nutrition and health section of the Pistachio Growers website.  You can’t make this stuff up.

Hey.  If that’s all it takes, give it a try (I guess).

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Mar 13 2023

Industry-funded study of the week: Walnuts

I always enjoy the Headline vs Study section of the newsletter, Obesity and Energetics Offerings.

I particularly like this one because the headline says one thing but the study says another, and the authors put a positive spin on the results (interpretation bias).

The study: The Effects of Walnuts and Academic Stress on Mental Health, General Well-Being and the Gut Microbiota in a Sample of University Students: A Randomised Clinical Trial.  Nutrients 202214(22), 4776; https://doi.org/10.3390/nu14224776

Rationale: Poorer mental health is common in undergraduate students due to academic stress. An interplay between stress and diet exists, with stress influencing food choices.

Results: Academic stress was associated with lower gut microbial diversity in females, which was improved by walnut consumption.  The effects of academic stress or walnut consumption in male participants could not be established due to small numbers of participants. Thus, walnut consumption may have a protective effect against some of the negative impacts of academic stress, however sex-dependent mechanisms require further study.

Overall conclusion: While daily consumption of walnuts could not alleviate disturbances in mood, it had a protective effect against the negative impacts of academic stress on mental health…daily walnut consumption over 16 weeks was able to alleviate the negative effects of academic stress on the diversity of the gut microbiota in females, however the relevance of these changes to the biochemistry of chronic stressors such as academic stress requires further study.

Funding: This research was co-funded by the University of South Australia (UniSA) and the California Walnuts Board & Commission…Walnuts for the study participants were provided by the California Walnuts Board & Commission. ..We thank Walnuts Australia for providing walnuts to the control group (upon completion of the study)….

Conflicts of interest: The sponsors had no role in the design, execution, interpretation, or writing of the study. The authors declare no conflict of interest.

Comment: The study didn’t show much, despite the enormous amount of work that went into it.  This looks like an excellent example of interpretation bias—putting a positive spin on barely significant results.  Industry-funded research usuall gets interpreted positively and recipients of industry funding believe that it does not influence them or cause conflicted interests.  But much research says it does.  And then, of course, this is a study of the effects of one food, usually not eaten in large amounts (nuts are expensive!) in diets containing large numbers of other foods.  Attributing big health effects to any one food hardly ever makes sense.

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For 30% off, go to www.ucpress.edu/9780520384156.  Use code 21W2240 at checkout.

 

Feb 27 2023

Industry funded study of the week: watermelon, of all things

The study: The Effect of Watermelon Juice Supplementation on Heart Rate Variability and Metabolic Response during an Oral Glucose Challenge: A Randomized, Double-Blind, Placebo-Controlled Crossover Trial.

Methods:  This was a two-week controlled clinical trial to measure the effects of watermelon juice on responses to oral glucose challenge tests in healthy young adults.  These usually decrease heart rate variability (not good).

Results: Watermelon juice countered the reduction in heart rate variability.

Funding: “This research was funded by the National Watermelon Promotional Board.”

Comment: I learned about this study from an article in NutraIngredients-USA: “Watermelon juice may decrease dysfunctsion linked to hyperglycemic episodes.” That headline made me ask my usual question: Who paid for this?  Bingo.

I give NutraIngredients much credit for the funding reveal right after the first paragraph, and for its clear explanation of a complicated study rationale and design.

The authors say they have no conflicts of interest to declare.  I continue to believe that the funding source establishes an automatic conflict of interest.

Once again, as I discuss in detail in my book, Unsavory Truth, the key point about industry-funded studies is that funding recipients do not recognize the influence or the conflict.

But what a coincidence that industry-funded studies so often come out with results favorable to the sponsor’s commercial interest, which in this case is this: The National Watermelon Promotional Board “operates with a single objective: to increase consumer demand for watermelon through promotion, research, and educational programs.”