by Marion Nestle

Currently browsing posts about: Fruit

Jul 8 2024

Industry-funded study of the week: prunes and osteoporosis

I just ran across this one.  The Prune Study?  To prove that prunes prevent osteoporosis?  Who could possibly be paying for this?

The study: Koltun, K.J., Strock, N.C.A., Weaver, C. et al. Prunes preserve cortical density and estimated strength of the tibia in a 12-month randomized controlled trial in postmenopausal women: The Prune Study. Osteoporos Int 35, 863–875 (2024).

Method: “evaluate the effects of 50 g and 100 g of prunes vs. a Control group on vBMD, bone geometry, and estimated strength of the radius and tibia via peripheral quantitative computed tomography (pQCT) in postmenopausal women. Women (age 62.1 ± 5.0yrs) were randomized into Control (n = 78), 50 g Prune (n = 79), or 100 g Prune (n = 78) groups.”

Results: “The most notable effects were observed at the 14% diaphyseal tibia in the Pooled (50 g + 100 g) Prune group, in which group × time interactions were observed for cortical vBMD (p = 0.012) and estimated bone strength (SSI; p = 0.024); all of which decreased in the Control vs. no change in the Pooled Prune group from baseline to 12 months/post.”

Conclusion: “Prune consumption for 12 months preserved cortical bone structure and estimated bone strength at the weight-bearing tibia in postmenopausal women.”

Funding: “We thank the California Prune Board (Award Number: 180215) for the funding and prunes.”

Comment: The California Prune Board is working hard on this.  I’ve posted at least one previous study on the same theme.  I’ve read the Results several times and still am not getting what’s claimed versus ‘no change in the Pooled Prune group from baseline to 12 months/post.'”  But even if there is an effect, the question is: compared to what?  Do other dried fruits provide similar effects?  What about whole fruits?  This is a one-food study designed to produce results that can be used in marketing.  What’s going on here?

We Work Hand-in-Hand with California’s Prune Growers and Handlers

The California Prune Board (CPB) works to unite California’s diverse prune growers and handlers around activities that benefit the industry today and pave the way for its bright future. As we all know, California Prunes are the best in the world – and CPB serves the industry by helping to drive demand and premium value.

Doing a good job?  You decide.

Jun 24 2024

Industry-funded studies of the week: Grapes

The California Table Grape Commission funds lots of research for an explicit purpose: “to help discover how and why grapes are beneficial to health.”

It lengthy list of funded projects is here.  Published studies are here.

You want to do one of these studies?  Let them know here.

Grape research is conducted using a freeze-dried table grape powder, designed to facilitate reproducible data and to provide researchers with a grape sample that is available year-round. Additionally, a grape powder placebo is made available.

Comment: If you want funding, you need to design your study to show benefits.  The Commission is unlikely to risk funding proposals unlikely to show benefits.  [Thanks to David Michaels for sending this one].

And Charles Platkin sent me the press release for one of the Commission’s funded studies: Hu, W., Zheng, R., Feng, Y., Tan, D., Chung-Tsing, G.C., Su, X., and Kim, J.E. (2023). Impacts of regular consumption of grapes on macular pigment accumulation in Singapore older adults: a randomized, controlled trial. Food Funct. 14, 8321-8330. Doi: 10.1039/d3fo02105j.  The abstract is here.

Conclusions: Regular intake of grapes may improve eye health in Singapore older adults, specifically in augmenting MPOD, which can be explained by an increase in plasma total antioxidant capacity and phenolic content, and the downregulation of AGEs.

I’m all for eating grapes and every other fruit.  Does one kind of fruit have more substantial effects on health than any other?  The study did not compare grapes to any other fruit; it just looked at the benefits of grapes.

I’m guessing lots of other fruits will do the same.

The moral: eat a variety of fruits and vegetables.  And be skeptical about the importance of studies like this.

May 9 2024

Industry-funded study of the week: mangos

Usually, I post something about research conflicts of intereest on Mondays, but am doing that today instead.

Three readers sent news about this study to me, so for that alone it’s worth sharing.

First, the press release:

Associations between mango eaters and moms-to-be: better diets and improved nutrient intakes: New NHANES analysis reveals meals including mangos associated with higher healthy eating index and better nutrition for healthy pregnancies.

Any time you see a headline like this, your first question should be: Who paid for this?

The study: Mango Consumption Was Associated with Higher Nutrient Intake and Diet Quality in Women of Childbearing Age and Older Adults.  Kristin Fulgoni and Victor L. Fulgoni III. Nutrients 202416(2), 303;

Conclusion: “This study suggests incorporating mango into the diet could increase select nutrient intake as well as diet quality in specific life stages of adult Americans.”

Funding: “This research was funded by the National Mango Board.”  [Bingo!]

Conflicts of interest: V.L.F.III and K.F. are employees of Nutrition Impact, LLC, a food and nutrition consulting firm which analyses NHANES data for numerous food and beverage companies and related entities. Nutrition Impact has a contract with the National Mango Board.

Comment: The National Mango Board contracted with the authors to produce this analysis. Its results are predictable.  Guess what: eating fruit increases intake of the nutrients contained in that fruit.  Eating fruit increases the quality of the diet.  I could have told them that.

I do love mangos, although they taste much better—like eating perfume—in their countries of origin.  I’m allergic to their skins and pits, however, and have to eat them carefully.  The Mango Board must think research results like this will increase sales.

Here’s how the Mango Board advertises this fruit:

Mangos pack a nutritional punch.

  • Each serving of mango is fat free, sodium free and cholesterol free.
  • Mangos contain over 20 different vitamins and minerals, helping to make them a superfood.

Superfood?  A marketing term.

Apr 22 2024

Industry-funded study of the week: Prunes

I learned about this one from this article:  Prune consumption may prevent bone loss for postmenopausal women.  Dietary supplementation with prunes can have a broad range of effects on immune, inflammatory and oxidative stress markers in postmenopausal women, according to a recent study…. Read more

When I see a headline like this, my first question is , as always, who would pay for something like this?

I went right to the study:  De Souza MJ, Strock NCA, Williams NI, Lee H, Koltun KJ, Rogers C, Ferruzzi MG, Nakatsu CH, Weaver C. Prunes preserve hip bone mineral density in a 12-month randomized controlled trial in postmenopausal women: the Prune Study. Am J Clin Nutr. 2022 Oct 6;116(4):897-910. doi: 10.1093/ajcn/nqac189.

Conclusion: “The results of this investigation provide compelling evidence of the long-term efficacy of daily prune consumption.”

Funding: We thank the California Prune Board (Award Number: 180215) for the funding and prunes and the participants in this study.

Author disclosures: CW and CR are members of the Nutritional Advisory Panel for the California Prune Board. All other authors report no conflict of interest.

Comment: Bingo on this one.  Wouldn’t it be wonderful if all you had to do to prevent bone loss was to eat 5 prunes a day?   Go for it!

Mar 25 2024

A rare gem: an industry-funded study with a negative result, and for blueberries yet!

I’ve posted several studies sponsored by the blueberry industry , most recently on their effects on menopausal symptoms.  Blueberry trade associations, as I discuss in my book Unsavory Truth: How the Food Industry Skews the Science of What We Eat, led the way in promoting research suggesting this fruit is a “superfood.”

If only.

They are still at it, apparently, but sponsorship does not always guarantee the desired outcome.  Here is a rare exception to the rule that industry-sponsored studies almost invariably give results favorable to the sponsor’s marketing interest.  Let’s give credit where it is due.

  • The study:  Chronic and postprandial effect of blueberries on cognitive function, alertness, and mood in participants with metabolic syndrome – results from a six-month, double-blind, randomized controlled trial.  The American Journal of Clinical Nutrition.  Available online 6 February 2024,
  • Methods: “A double-blind, randomized controlled trial was conducted, assessing the primary effect of consuming freeze-dried blueberry powder, compared against an isocaloric placebo, on cardiometabolic health >6 mo and a 24 h postprandial period (at baseline).”
  • Results: “Postprandial self-rated calmness significantly improved after 1 cup of blueberries (P = 0.01; q = 0.04; with an 11.6% improvement compared with baseline between 0 and 24 h for the 1 cup group), but all other mood, sleep, and cognitive function parameters were unaffected after postprandial and 6-mo blueberries.”
  • Conclusion: “Although self-rated calmness improved postprandially, and significant cognition-metabolite associations were identified, our data did not support strong cognitive, mood, alertness, or sleep quality improvements in MetS participants after blueberry intervention.”
  • Conflict of interest: “AC reports financial support provided by the US Highbush Blueberry Council (USHBC) and Biotechnology and Biological Sciences Research Council (BBSRC, UK). AC and EBR both act as advisors and consultants to the United States Highbush Blueberry Council grant committee. All other authors report no conflicts of interest.”
  • Funding: “This work was supported by the United States Highbush Blueberry Council with oversight from the USDA and the Biotechnology and Biological Sciences Research Council (United Kingdom). The funders of this research had no involvement in this publication and have placed no restrictions on the publication of these data.”

Comment: In this instance, the last statement could well be correct (it isn’t always, alas).  I like blueberries but they are not a superfood.  There is no such thing as a superfood.  If you want to eat healthfully, by all means eat fruit—and enjoy the ones you like best.

Dec 6 2023

Yet another Salmonella outbreak from cantaloupe

I’m having a hard time with this one.

Once again, the FDA is warning all of us : “Do not eat, sell, or serve recalled cantaloupes or recalled products containing pre-cut cantaloupe.”

The warning lists the products implicated and all the ones that have been recalled.

The CDC says much the same:

CDC is concerned about this outbreak because the illnesses are severe and people in long-term care facilities and childcare centers have gotten sick. Do not eat pre-cut cantaloupes if you don’t know whether Malichita or Rudy brand cantaloupes were used.

As of November 30, the toll is:

Total Illnesses: 117
Hospitalizations: 61
Deaths: 2

But that’s only in the U.S.  Canada reports illnesses too: 63 sick, 17 hospitalized and 1 death.

This, mind you, is from eating cantaloupe.

It’s not that nobody knew cantaloupe poses special safety problems.  It’s grown on the ground and is hard to wash.  If it is grown anywhere near animal wastes, it has a high risk of getting Salmonella on its rind.  Cutting through the rind can move harmful bacteria on the rind into the interior.

Food safety lawyer Bill Marler, who tracks such things, reminds us of previous lawsuits over cantaloupe food poisonings.

He also has some useful things to say about Salmonella during a Cantaloupe Outbreak – Symptoms and Treatment

Cantaloupes, he points out, might still be in season, but Salmonella should not be.

He quotes Perdue (sic Purdue) Extension on how to make cantaloupe safer: scrub and wash in very hot water.

But Marler has been quoted as saying he does not eat cut fruit (implying you should not either).

What’s infuriating about all this is that Congress passed the Food Safety Modernization Act to give the FDA the power to require safety plans from producers of every food under its jurisdiction.  This means cantaloupe growers are supposed to take steps—and test—to make sure the fruit is not contaminated with pathogenic bacteria.

Clearly, the system isn’t working.

The FDA needs to find out why not.

The FDA is chronically and infamously underfunded for what it is supposed to do.

Congress needs to pay attention to this issue.

Nobody should get this sick from eating cut fruit.

And if you haven’t seen the film featuring Marler (I’m in it too, briefly), take a look at Poisoned on Netflix.  It talks about cantaloupe, among other things worth knowing.

Oct 19 2023

A feast for the eyes: USDA’s Pomological Collection

I ran across a notice about this video: The USDA’s wondrous fruit watercolors.  It’s only 5 minutes and a revelation.

It’s just what we need this week—something lovely at a dark time.

I had never heard of the USDA’s collection of 7500 hand -illustrated fruits and vegetables, most of them contributed by women.

I’m happy to know about them.  The illustrations are available online at the National Agricultural Library.

You can search for images here.

They are in the public domain.

Overwhelmed as I am with an overabundance of Concord grapes this year, I searched for them.

They look good enough to eat, no?

This collection is a national treasure and I am thrilled to know about it.

Sep 18 2023

Fruit-industry studies of the week: Blueberries

I missed posting these last week (oops).

Blueberries set the standard for industry-funded studies (I discussed the origins of blueberry-industry funding in my book, Unsavory Truth).  Blueberry producers are still at it.  Here are two examples.

I.  This one started with a press release sent to my email:

From: Blueberries <>
Date: August 29, 2023 at 11:59:59 AM EDT
Subject: Study Alert: New Research Links Blueberries to Gut Health Benefits

A new study published in Nutrients suggests blueberries may hold benefits for those suffering from functional gastrointestinal disorders (FGID). In this study, FGID patients saw greater abdominal symptom relief and improved markers of well-being, quality of life, and life functioning after consuming freeze-dried blueberry powder for 6 weeks as compared to a placebo treatment.

The study: Wilder-Smith CH, Materna A, Olesen SS. Blueberries Improve Abdominal Symptoms, Well-Being and Functioning in Patients with Functional Gastrointestinal Disorders. Nutrients. 2023; 15(10):2396.

Conclusion: Blueberries relieved abdominal symptoms and improved general markers of well-being, quality of life, and life functioning more than placebo in patients with FGID. Consequently, the polyphenol and fiber components of blueberries exert broad beneficial effects separate from the sugars present in both treatments.

Funding: This research was funded by a grant from the US Highbush Blueberry Council.

Comment: Of course it was.

II.  I read about this one in ConscienHealth.

Burning Fat with Wild Blueberries in 11 Athletes

This is nearly perfect clickbait that is just about meaningless for an average person in real life. Researchers did a study of fat oxidation after consuming freeze-dried powder from wild blueberries. They found an increased oxidation rate associated with consuming that powder in the 11 aerobically trained males they studied. So the press office at Cal Poly Humboldt, where the researchers work, issued a release saying wild blueberries help with burning fat.  From there, twitter and health reporters take the next leap, writing headlines like “eating wild blueberries can help you lose weight.”

The study: Pilolla KD, Armendariz J, Burrus BM, Baston DS, McCarthy KA, Bloedon TK. Effects of Wild Blueberries on Fat Oxidation Rates in Aerobically Trained Males. Nutrients. 2023; 15(6):1339.

Conclusion: “Results indicate that WBs may increase the rate of FAT-ox during moderate-intensity activity in healthy, active males.”

Funding: “This research was funded by Cal Poly Humboldt’s Dean of Research.* Freeze-dried Wild blueberry powder was donated by the Wild Blueberry Association of North America (WBANA).

Comment: I agree that simply providing product to be tested is not an earth-shaking conflict of interest, but because the powder came from the WBANA the ties seem closer.  In any case, the idea that blueberry powder—not nearly as delicious as the real thing—can have these kinds of effects should raise eyebrows from the get go.  Studies of the health effects of one sincle food always require critical thinking and more than a modicum of skepticism.

As for the asterisk*:  My son went to Humboldt State College (long before it was taken over by Cal Poly) so I was especially interested in this.