by Marion Nestle

Currently browsing posts about: Sponsored-research

Sep 12 2023

Fruit-industry study of the day. II. Figs.

For this one I thank Jerry Hagstrom, who writes The Hagstrom Report (Ag news as it happens) to which I subscribe.

This too begins with a press release: “REDISCOVER FIGS: THE ANCIENT FRUIT WITH MODERN APPEAL: Newly Published Literature Review Suggests the Intake of Figs Regularly in the Diet, Alone or with Other Dried Fruits, Increases Select Micronutrient Intake and is Associated with Higher Diet Quality.”

The study: Sandhu AK, Islam M, Edirisinghe I, Burton-Freeman B. Phytochemical Composition and Health Benefits of Figs (Fresh and Dried): A Review of Literature from 2000 to 2022. Nutrients. 2023 Jun 3;15(11):2623. doi: 10.3390/nu15112623.
Conclusion: Data suggest that the intake of figs regularly in the diet, alone or with other dried fruits, increases select micronutrient intake and is associated with higher diet quality, respectively. Research in animal and human models of health and disease risk provide preliminary health benefits data on figs and their extracts from fig parts; however, additional well-controlled human studies, particularly using fig fruit, will be required to uncover and verify the potential impact of dietary intake of figs on modern day health issues.
Funding: This research was funded by California Fig Advisory Board.
Comment: The title of this study triggered my usual question: “who paid for this?” In this case, the authors get high marks for cautious interpretation of their findings and explicit statement about what is and is not known.
Despite the promising preliminary research of figs and extracts from fig parts, additional well-controlled human studies, particularly using fig fruit, will be required to uncover and verify the potential impact of dietary intake of figs or nutraceutical applications on critical health issues such as managing cardiovascular disease, diabetes, and supporting gut health. Other areas such as satiety and cognitive function may also be worthy of exploration as evidence develops.
Sep 11 2023

Fruit industry-funded study of the day: I. Strawberries

I am way behind on posting all the industry-funded studies sent to me and collected, so will share a week’s worth of fruit studies .  This is to emphasize the obvious point that fruit is good for you, but one is not necessarily better than another–except to its marketers.  Enjoy!

Here’s the first: strawberries.

I heard about this from two news releases, and because it was sent to me by Charles Platkin, Executive Director, Center for Food as Medicine  and Distinguished Lecturer at Hunter College, City University of New York.

Wow.  This is exciting.  I had strawberries with my cereal for breakfast this morning.

I could not wait to read the study.

Uh oh.  Not yet published.  But given in a poster session at the American Society for Nutrition meetings in Boston last month.

  • Title: The Impact of Strawberries on Cognition and Cardiovascular Health of Older Healthy Adults: A Randomized, Crossover, Double-Blind, Placebo-Controlled Clinical Trial .
  • Objectives: The polyphenolic compounds in strawberries may improve cognitive function and cardiovascular health due to their antioxidant capacities. This study aimed to examine the effects of strawberries on cognitive function and cardiometabolic health in healthy aging adults.
  • Methods:  This was a randomized, crossover, double-blind, placebo-controlled clinical trial with 35 healthy older adults  given 26 grams of freeze-dried strawberry powder (not strawberries) and a control powder daily for 8 weeks each.
  • Results:  The strawberry powder group increased processing speed.  The control group increased episodic memory.  : The powder also had other effects: “Strawberry consumption reduced systolic blood pressure…Total antioxidant capacity significantly decreased during the control trial …and significantly increased with strawberry consumption.”
  • Conclusions: This study demonstrates that daily consumption of 26 grams of freeze-dried strawberry powder moderately improves cognitive processing speed, lowers systolic blood pressure, and increases total-antioxidant capacity, potentially promoting cognitive function and improving cardiovascular risk factors.
  • Funding Sources: This study was funded by California Strawberry Commission.

Comment: Of course it was.  Who else would care about the effects of strawberry powder.  Not that no other fruit powders were tested; I would expect all of them to produce similar effects, whatever those effects might be.  Given that the control group performed better on memory tests, you could interpret the results as not particularly meaningful.  But one characteristic of industry funded studies is to put a positive spin on whatever results occur.  We can argue about the methods when the study is actually published.  In the meantime, we have press releases.

Oh.  And my morning strawberries were somewhat local, red all the way through, and tasted like strawberries.  Do I feel smarter as a result?  Sure, why not.

Aug 28 2023

Industry-funded study of the week: Beer!

A reader, Emma Calvert, a Senior Food Policy Officerfor the European Union in Brussels, sent me “this article.  She also pointed me to the article Food Navigator wrote about it: “Review hails health benefits of beer-gut alliance.”

Eager to find out what the “beer-gut alliance” might be, I went right to it.

The study: Beer-gut microbiome alliance: a discussion of beer-mediated immunomodulation via the gut microbiome.” Silu Zhang, Shuo Jin, Cui Zhang, Shumin Hu, Huajun Li.  Front. Nutr., 25 July 2023.  Volume 10.

Background: “As a long-established fermented beverage, beer is rich in many essential amino acids, vitamins, trace elements, and bioactive substances that are involved in the regulation of many human physiological functions.  The polyphenols in the malt and hops of beer are also important active compounds that interact in both directions with the gut microbiome.”

Methods: “This review summarizes the mechanisms by which polyphenols, fiber, and other beneficial components of beer are fermentatively broken down by the intestinal microbiome to initiate the mucosal immune barrier and thus participate in immune regulation.”

Conclusion: “Beer degradation products have anti-inflammatory, anticoagulant, antioxidant, and glucolipid metabolism-modulating potential. ..The positive effects of bioactive substances in beer in cancer prevention, reduction of cardiovascular events, and modulation of metabolic syndrome make it one of the candidates for microecological modulators.”

Funding: “This study was supported by the Open Research Fund of State Key Laboratory of Biological Fermentation Engineering of Beer, under grant no. K202101.”

Conflict of interest: “CZ and SH were employed by Tsingtao Brewery Co. Ltd.  The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.”

Comment: This seems like a lot to claim for beer.  Vested interest?  Yes.  The State Key Beer Lab is part of the Tsingtao Brewery Co. Ltd, Qingdao, 266100, China and two of the authors work for the company.  Why do this study?  To distract attention from the harmful effects of alcohol consumption (where do I begin?) and from its calories, and instead give beer a health aura.

Beer, alas, is not a health food, best consumed in moderation if at all.


Aug 23 2023

Does industry involvement in research constitute a conflict of interest?

Last week, my industry-influenced study of the week involved kombucha, although the involvement appeared minimal.

All kombucha and placebo drinks were donated by Craft Kombucha. Craft Kombucha did not have any access to data reported in this study. No author has any financial ties with Craft Kombucha. SD was employed by MedStar Health. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

One of the authors of the study, Daniel Merenstein, wrote to object to the way I characterized it (quoted with his permission).

…But you do make it very clear in the article that all industry did was donate free drinks and had no access to data. Not sure how that really deserves being called influence. But my much larger point is this statement, ” It’s easy to find claims for its health benefits if you search for them, but much harder to find science to back them up.  IIf you can demonstrate benefits, you can sell more products.  Hence, this study.

I think it is exactly the opposite. It is much easier to just say your product works or even better yet to get an influencer to drink your product.

But to actually put your product into scientist’s hands and have no access to data or publication is a huge step forward in food science. Look at JAMA every week, almost all the drug studies are -. The kombucha maker should be applauded for their bravery.

We didn’t going looking for a + outcome but registered our trial and stated a priori exactly what we would be looking at and reporting. This study has many limitations but not the ones you mentioned.


I appreciate thoughtful and respectful letters like this .  This one especially deserves a response.  Dr. Merenstein implies that this is an investigator-initiated study designed to test an investigator-initiated hypothesis.  Such things do happen.  Unfortunately, they are not the norm.

Here’ what concerned me about the study:

  • It involved a kombucha company, even if lightly.  Much evidence demonstrates that company involvement in research ia highly correlated with positive outcomes, so much so that it has a name, the “funding effect.”
  • Funding influence is thorougly demonstrated to occur at an unconscious level; investigators do not intend to be influenced, are unaware of the influence, do not recognize it, and deny it (even in the face of much research to the contrary).  The unconscious influence usually shows up in the way the research question is asked or in the interpretation of the results.
  • Statements that funders have no involvement in the research have coften been shown to be false.  Exceptions do occur; this may well be one of them.
  • This is a one-food study.  It is impossible to control such studies for dietary and other lifestyle confounders unless done in a locked metabolic ward.

On this last point, I am always suspicious of one-food studies because I find it hard to believe that a single food can make a measureable difference in chronic disease outcome.

I would like to know a lot more about how the microbiome works before being convinced that kombucha has any special health benefits (I do think it is delicious).

To their great credit, these authors fully disclose the limitations of their study (it was small) .

Dr. Merenstein says this study is really about the science.  In this case then, the bias is one shared by all scientists—a belief and the desire to prove it,–in this case that kombucha has particular health benefits .  If scientists didn’t have such beliefs and desires, no science would ever get done.

Such personal biases are indeed quite different from bias induced by financial interests with a company making a product.

Perhaps I misjudged this one.  If so, I owe Dr. Merenstein and his colleagues a sincere apology, here offered.

I thank him for writing and giving me the opportunity to discuss these issues again.

(For detailed discussion and references on issues related to industry research funding, see my book, Unsavory Truth: How the Food Industry Skews the Science of What We Eat).

Aug 21 2023

Industry-funded study of the week: Pecans again

At least five readers recently sent me items about research funding by pecan trade associations and I especially thank Lisa Young and Matthew Rees.

But I will begin with Headline vs. Study from the weekly newsletter (invaluable) Obesity & Energetics Offerings (8-18-23).

Guess who funded this:

  • Funding: We acknowledge funding from the Texas Pecan Board and a grant from the Texas Department of Agriculture.
  • Conflicts of Interest: The authors declare no conflict of interest.

Comment: Acknowledged or not, the funding establishes a conflicted interest.  Industry funding influences the outcome of research, whether the researchers recognize it or not.  I will say more about that this week in response to a comment from a reader.

In the meantime, here is another one.

  • The study: McKay DL, Eliasziw M, Chen CYO, Blumberg JB. A Pecan-Rich Diet Improves Cardiometabolic Risk Factors in Overweight and Obese Adults: A Randomized Controlled Trial. Nutrients. 2018 Mar 11;10(3):339. doi: 10.3390/nu10030339.
  • Acknowledgments: This work was supported by the U.S. Department of Agriculture (USDA) Agricultural Research Service under Cooperative Agreement No. 58-1950-014 and the National Pecan Shellers Association. The National Pecan Shellers Association provided the pecans for the intervention.
  • Conflicts of Interest: The authors declare no conflict of interest. The founding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results.

Comment:  The role of the National Pecan Sheller sAssociation is not clear (to me) from these acknowledgments.  Did the trade association initiate or fund the study, or was its involvement strictly in providing pecans?   Is there a difference?  Perhaps.  It is possible for studies involving vested financial interests to be done objectively, but studies of the “funding effect”—a higher probability of favorable outcomes—to be the norm.  Again, I will speak to this point later this week.

In the meantime, for detailed discussion and references of this issue, see my book, Unsavory Truth: How the Food Industry Skews the Science of What We Eat.



Aug 7 2023

Industry-funded study of the week: sugar!

My thanks to Paola Baratto for sending this one.

The study: . Intakes of Added Sugars, with a Focus on Beverages and the Associations with Micronutrient Adequacy in US Children, Adolescents, and Teens (NHANES 2003–2018).  Ricciuto L, Fulgoni VL III, Gaine PC, Scott MO, DiFrancesco L.   Nutrients. 2023; 15(15):3285.

Method: This is an analysis of links between added sugars from different kinds of drinks and nutrient adequacy in children using combined data from 8 consecutive NHANES surveys (2003-2018).

Results: I found the results hard to understand because they are presented selectively by age, and they compare nutrient intakes to estimated average requirements.  Here is what I think they mean:

  • 2 to 8 year olds: If they got their sugar from flavored milk, they had better calcium intake.
  • 9 to 18 year olds: If they got their sugar from soft drinks, coffee, or tea, thei had worse intakes of magnesium and vitamins A and C.  But if they got their sugars from fruit drinks or flavored milk, they had better intake of vitamin C (from the fruit drinks), and of calcium, magnesium, phosphorus, vitamin A, and potassium (from the flavored milk).
  • 9 to 18 year olds: Higher intake of added sugars in the overall diet was associated with bettter intake of vitamins and minerals.

Conclusion: The results suggest that the relationship between added sugars intake and micronutrient adequacy depends on the added sugar sources and their nutrient composition.

Funding: The funding for this research was provided by The Sugar Association, Inc. P.C.G. and M.O.S. are employed by The Sugar Association Inc., had input in the study design, and reviewed and edited the manuscript.

Comment: The Sugar Association’s purpose in sponsoring this study is to buttress its argument that sugary drinks and foods have nutrients and, therefore, do not warrant restrictions.  If you get the idea from this study that the more sugary foods you eat, the more nutrients you and your kids get, the Association will be even happier.  Sorry Sugar Association, but it is quite possible to consume adequate intakes of vitamins and minerals without eating sugary foods and doing so will make calories easier to control.  With this study, the Sugar Association got what it paid for.

Jul 31 2023

Industry-funded study of the week: Matcha

Thanks to Matthew Kadey for sending this one.  Matcha is a new one for me.

The study: Matcha green tea beverage moderates fatigue and supports resistance training-induced adaptation.  Shigeta M, et al.  Nutrition Journal volume 22, Article number: 32 (2023)

Methods: Healthy, untrained men were randomized into placebo and matcha groups. Participants consumed either a matcha beverage containing 1.5 g of matcha green tea powder or a placebo beverage twice a day and engaged in resistance training programs for 8 (trial 1) or 12 weeks (trial 2).

Results: In trial 1, maximum leg strength after training tended to increase more in the matcha group than that in the placebo group. In the matcha group, subjective fatigue after exercise at 1 week of training was lower than that in the placebo group. Gut microbe analysis showed that the abundance of five genera changed after matcha intake. The change in RuminococcusButyricimonas, and Oscillospira compositions positively correlated with the change in maximum strength. In trial 2, the change in skeletal muscle mass in response to training was larger in the matcha group. In addition, the salivary cortisol level was lower in the matcha group than that in the placebo group.

Conclusion: Daily intake of matcha green tea beverages may help in muscle adaptation to training, with modulations in stress and fatigue responses and microbiota composition.

Funding: This work was supported by the Matcha and Health Research Group and the Japan Society for the Promotion of Science (JSPS) KAKENHI: Grant-in-Aid for Scientific Research,

Competing interests: Although the Matcha and Health Research Group was not involved in conducting experiments or data analysis, test samples were supplied from Nestlé Japan Ltd., a constituent organization of the Matcha and Health Research Group.

Comment:  Matcha is powdered green tea, so whatever is in it is more concentrated than in regular teas.  Besides that, is there anything special about matcha?  The study did not compare matcha to other teas, so it’s hard to know.  I’m curious about the funder.  I can’t find anything about it online other than its sponsorship of many studies about matcha, all with positive results.   I’m guessing that someone who profits from matcha sales is behind these studies, but can’t tell for sure.  If you enjoy matcha, by all means drink it.  Teas are healthy beverages  But reserve judgement on the research linking it to health miracles.  The studies I’ve seen pretty much all say: “more research needed.”

Jul 27 2023

Industry-funded research #4: why it matters

I posted several examples of industry-funded studies this week in part to reduce my backlog but also because of charges that (1) doing so constitites ad hominem (personal) attacks on authors, (2) I should be focusing on the science, not who paid for it, and (3) I have my own ideological biases.

To the first point:

I do not see industry funding of research as a personal matter.  I see it as a systematic problem.

If I see a study titled “Effect of food product X on disease Y,” I can often guess that

  • The food’s manufacturer or trade association paid for it
  • The study outcome will be favorable to the funder’s commercial interests

This phenomenon is so systematic that it has a name: The Funding Effect.

To the second point

Researchers who study funding effects, and there are many, note that the scientific conduct of the studies is not usually an issue.  Instead, the influence of the funders shows up in the way the research question is framed or the results are interpreted.

The easiest way to explain the research question bias is to cite the requests for research proposals I often receive from food trade associations.  These say: “we have (this much money) for research to demonstrate the benefits of our product on (one or more of these conditions).”

These groups will not fund research proposals unlikely to show benefits.

As for interpretation, industry-funded studies tend to report null results as positive; I posted several such examples this week.

To the third point

Yes, I have ideological or opinion biases and I try to be as clear as I can about them.  All investigators have such biases; otherwise they wouldn’t be doing science.  We all have something we believe in that we would like to prove.  Such biases are not discretionary; everyone has them.  In contrast, industry funding is about selling products, not science and is completely discretionary; investigators can do science without it.

The evidence?

I review the evidence for what I’ve just said here in my book, Unsavory Truth: How Food Companies Skew the Science of What We Eat.

In it, I cite many other books and papers addressing these points.

We all come to the same conclusions:

  • Industry funding biases research.  But funded investigators do not recognize the influence, and deny it.
  • The statement that accompanies many disclosure statements—“The funder had no influence on the design, conduct, interpretation, or publication of the results,”—is often untrue and must be taken with some degree of skepticism.

I see industry funding of food and nutrition research as a serious problem for public perception.  Even when the research is not conflicted, it appears conflicted.  That alone is a systematic problem.