by Marion Nestle

Currently browsing posts about: Fruit

Jan 17 2022

Industry-funded study of the week: grape powder

Thanks to Daniel Bowman Simon for pointing me to this one.

The study: Effect of Standardized Grape Powder Consumption on the Gut Microbiome of Healthy Subjects: A Pilot Study.  Jieping Yang, et al.  Nutrients. 2021 Nov; 13(11): 3965. doi: 10.3390/nu13113965

Methods: Study subjects had to eat 46 grams a day of grape powder (the equivalent of two daily grape servings) for 4 weeks.  Their microbiomes and serum cholesterol levels were compared to those observed during a baseline 4-week period.

Conclusions: “In conclusion, grape powder consumption significantly modified the gut microbiome and cholesterol/bile acid metabolism.”

Funding: This research was funded by California Table Grape Commission.

Conflicts of Interest: No potential conflict of interest was reported by the authors.

Comment: The authors see no conflicts of interest but they accepted funding from the Grape Commission for the study.  California grape producers issue requests for research proposals to demonstrate the health benefits of grapes using grape powder, so I’m guessing the authors applied for this funding.  As I explain in my book, Unsavory Truth, industry influence on research outcome is well documented, but often unrecognized by recipients.  Funders typically get what they pay for.  Does grape powder duplicate the nutritional benefits of grapes?  Hard to say.  Are any of these results clinically important?  Ditto.

Nov 15 2021

Industry-funded study of the week: would you believe baobab?

I learned about this study from an article in FoodNavigator.com, “Baobab industry welcomes study linking the fruit to good gut health.”

The title raised the question, “Who funded this?”  Bingo, as it turns out.

Baobabs are enormous African trees that produce a highly fibrous fruit.

I can’t say it looks particularly yummy.  In fact, it is described as “floury, dry, and powdery” and works best as a powdered ingredient.

But the baobab industry?  Who knew such an entity existed?

It does.  Hence this study:

The study: A Pectin-Rich, Baobab Fruit Pulp Powder Exerts Prebiotic Potential on the Human Gut Microbiome In VitroMartin FoltzAlicia Christin ZahradnikPieter Van den AbbeeleJonas GhyselinckMassimo Marzorati.  Microorganisms. 2021 Sep 17;9(9):1981.

Methods: Test tube mixing of baobab powder with colonic bacteria.

Results: Baobab fruit pulp powder boosted colonic acidification across three simulated human adult donors due to the significant stimulation of health-related metabolites.

Conclusions: Overall, Baobab fruit pulp powder fermentation displayed features of selective utilization by host microorganisms and, thus, has promising prebiotic potential.

Funding: The studies described in this manuscript were performed at the request of and were funded by Döhler, 94295 Darmstadt, Germany  Surprise!  This company makes baobab powder.

Conflict of interest:  M.F. and A.C.Z. are employees of Döhler. While M.F. participated in the design of the study, the interpretation of the data, and the revision of the manuscript, M.F. did not participate in the collection and analyses of data.

Comment: No food, product, or ingredient is too obscure to avoid industry attempts to demonstrate that it can be marketed as a “superfood” (see, for example, this product).

Reference: For a summary of research on the “funding effect”—the observation that research sponsored by food companies almost invariably produces results favorable to the sponsor’s interests but that recipients of industry funding typically do not recognize its influence—see my book, Unsavory Truth: How Food Companies Skew the Science of What We Eat.

Oct 25 2021

Industry-funded study of the week: Would you believe Jackfruit?

Jackfruit?  No, I’m not kidding.

For one thing, it’s JSTOR Daily’s Plant of the Month: “The newly hot alternative to meat has a long history.”

Jackfruit is not new in South Asia and its surrounding regions, where it has been a culturally significant foodstuff for centuries. Nor is jackfruit new in the West. Rather, it has a long and disquieting history: British imperialists wielded jackfruit as a tool to provide cheap nutrition to enslaved and coerced laborers throughout their empire.

Here’s what it looks like on the tree:

Type 2 diabetes: Add green unripe jackfruit flour to your daily meal plan, it may help control Type 2 diabetes - The Economic Times

And off:

Fresh Jackfruit - Shop Fruit at H-E-B

If you are in the business of selling Jackfruit, or products made from it, you will want research demonstrating health benefits.

Voila!

The study: Efficacy of green jackfruit flour as a medical nutrition therapy replacing rice or wheat in patients with type 2 diabetes mellitus: a randomized, double-blind, placebo-controlled study  Gopal Rao, K. Sunil Naik, A. G. Unnikrishnan & James Joseph.  Nutrition & Diabetes volume 11, Article number: 18 (2021)

Methods: This was a randomized, double-blind, placebo-controlled study of patients with type-2 diabetes who were being treated with oral antihyperglycemic agents.  They were either given jackfruit flour 30 g/day (Group A) or placebo flour (Group B) for 12 weeks.

Results: Patients from Group A had a better reduction in glycosylated hemoglobin, fasting plasma glucose, and postprandial plasma glucose than patients in Group B.

Conclusion: This study demonstrates the efficacy of jackfruit flour in glycemic control as medical nutrition therapy replacing an equal volume of rice or wheat flour in daily meal.

Funding: Diet Fibre 365 Food Products Pvt Ltd, India.

Acknowledgment: “The authors would like to acknowledge Abiogenesis Clinpharm Pvt Ltd, Hyderabad, for medical writing assistance funded by Diet Fibre 365 Food Products Pvt Ltd, Mumbai, India.”

Competing interests: JJ is the inventor of Jackfruit 365™ Green Jackfruit Flour with a pending patent and CEO of God’s Own Food Solutions Pvt Ltd which along with its subsidiary Diet Fibre 365 Food Products Pvt Ltd manufactures and markets the product. AGR, KSN, and UAG have no conflict of interest to declare.

Comment: This is a classic example of the funding effect in nutrition research.  The author owns the Jackfruit flour and the company that markets it, and the funder wrote (OK, helped to write) the paper.  The results were predictable.

Reference: For a summary of research on the “funding effect”—the observation that research sponsored by food companies almost invariably produces results favorable to the sponsor’s interests, but that recipients of industry funding typically do not recognize its influence—see my book, Unsavory Truth: How Food Companies Skew the Science of What We Eat.

Sep 20 2021

Industry-funded study of the week: strawberries

A sharp-eyed reader, Paula Rochelle, sent me this one.  From the title alone, she suspected industry sponsorship.  Good thinking!

The Study: Dietary strawberry improves cognition in a randomised, double-blind, placebo-controlled trial in older adults.

Dietary intervention: For 90 days: “12 g of a lyophilised, standardised blend of SB sourced from equal parts of Albion, San Andreas, Camino Real and Well-Pict 269 varieties, twice daily (24 g/d, equivalent to two cups per serving of fresh SB).”

Results: “This study found that 90 d of dietary intervention with SB resulted in (1) improved word recognition and (2) improved spatial learning and memory in a virtual navigation task among healthy older adults.”

Conclusion: “In conclusion, these findings suggest that the inclusion of SB in the diet may aid in preserving some aspects of hippocampal cognitive function during normal ageing.”

Funding: The study was funded by the U.S. Department of Agriculture and California Strawberry Commission.

Conflicts of interest:  The authors declare that they have no conflicts of interest.

Comment: This study received partial support from USDA as part of its effort to promote fruit-and-vegetable consumption.  The California Strawberry Commission wants people to buy more strawberries.   It summarizes the research it sponsors on its website.  Everyone knows that eating fruits and vegetables is good for health.  Why does the Strawberry Commission go to all this trouble to demonstrate that strawberries are good for health?  My guess: to compete with blueberries for market share.  This, like other such studies, is about marketing.  The authors do not view strawberry industry funding as a source of conflicted interests.  They should.

Reference: For a summary of research on the “funding effect”—the observations that research sponsored by food companies almost invariably produces results favorable to the sponsor’s interests and that recipients of industry funding typically did not intend to be influenced and do not recognize the influence—see my book, Unsavory Truth: How Food Companies Skew the Science of What We Eat.

Aug 30 2021

Industry-funded study of the week: prunes, this time

My NYU colleague Mitchell Moss sent me this notice of new research: Eating just 5 prunes a day reduces risk of heart disease, inflammation.

That was worth tracking down and I soon found a press release from the California Prune Board: New study: Eating prunes daily improves risk factors for heart disease and inflammation

In a statement, the senior author says:

In this randomized, controlled study, researchers found that eating 50 grams of prunes (about 5-6 prunes) each day for just 6 months resulted in improved CVD risk biomarkers – including raising the body’s “good” cholesterol, known as HDL, and lowering the ratio of total cholesterol to HDL. Eating prunes daily also promoted higher antioxidant capacity and lowered levels of the inflammatory cytokines interleukin-6 and tumor necrosis factor-alpha associated with CVD risk. Notably, body mass index and weight of the study participants were maintained during the trial despite adding prunes to the usual diet.

The study:  Dried Plum Consumption Improves Total Cholesterol and Antioxidant Capacity and Reduces Inflammation in Healthy Postmenopausal Women

Dietary intervention: “48 postmenopausal women were randomly assigned to consume 0, 50, or 100 g of dried plum each day.”

Results: “After 6 months of intervention, total cholesterol (TC) in the 100 g/day treatment group (P = .002) and high-density lipoprotein cholesterol in the 50 g/day treatment group (P = .005) improved significantly compared to baseline.”

Conclusion: “…consumption of 50–100 g dried plums may improve CVD risk factors in healthy postmenopausal women by increasing total antioxidant capacity and antioxidant enzyme activity, lowering lipid peroxidation, and lowering IL-6.”

Authors’ statement: “The authors declare that there is no conflict of interest.”

Funding: “This study was funded by the San Diego State University Grant Program, the California Dried Plum Board (No. 57114A; ClinicalTrials.gov, No. NCT02325895), and the Kasch-Boyer Endowed Scholarship in Exercise and Nutritional Sciences in San Diego State University.”

Comment:  Add prunes to the long list of fruit-and-vegetable trade associations trying to convince you that their particular product has unique health benefits.  Prune sellers have a particular difficulty with sales: prunes have long been equated with laxatives.  Hence: the Dried Plum Board.  Also hence: health benefits beyond the digestive tract.

Do prunes have more general health benefits?  Why not?  All fruits and vegetables have health benefits.  Is one better than another?  Maybe in some ways, but the best approach is to eat as wide a variety as possible.

Eat the fruits you like!

Reference: For a summary of research on the “funding effect”—the observation that research sponsored by food companies almost invariably produces results favorable to the sponsor’s interests but that recipients of industry funding typically do not recognize its influence—see my book, Unsavory Truth: How Food Companies Skew the Science of What We Eat.

Jan 11 2021

Sponsored research study of the week: mangos and skin wrinkles (I’m not kidding)

I learned about this one from a press release: “Can eating mangoes reduce women’s facial wrinkles?”

new study from researchers at the University of California, Davis, finds eating Ataulfo mangoes, also known as honey or Champagne mangoes, may have another benefit — reducing facial wrinkles in older women with fairer skin. The study was published in the journal Nutrients.

Postmenopausal women who ate a half cup of Ataulfo mangoes four times a week saw a 23 percent decrease in deep wrinkles after two months and a 20 percent decrease after four months.

Surely, this can’t be serious?  Who paid for this?

The study: Prospective Evaluation of Mango Fruit Intake on Facial Wrinkles and Erythema in Postmenopausal Women: A Randomized Clinical Pilot Study.  Vivien W. Fam, Roberta R. Holt Carl L. Keen, Raja K. Sivamani .  and Robert M. Hackman.  Nutrients 202012(11), 3381; https://doi.org/10.3390/nu12113381

Method: Women were given either 85 g or 250 g of mangos to eat every day for 16 weeks.  Their wrinkles were photographed and measured before and after.

Conclusion: “The intake of 85 g of mangos reduced wrinkles in fair-skinned postmenopausal women, while an intake of 250 g showed the opposite effect.”

Funding: “This study was supported in part by a grant from the National Mango Board (NMB)…which also supplied the fresh mangos for the study. The NMB had no role in the study design, data collection, data analysis, manuscript preparation, or publication decision.”

Conflicts of Interest: The authors declare no conflict of interest.

Comment:  I love mangos (despite being somewhat allergic to them), but come on.  According to the press release, the researchers “said it’s unclear why consuming more mango would increase the severity of wrinkles but speculate that it may be related to a robust amount of sugar in the larger portion of mangoes.”  Another interpretation is that mangos have no effect (which makes more sense).  In any case, this study did not compare mangos to any other fruit.  This is a classic case of an industry-sponsored study coming out with results favorable to the sponsor’s interests and allowing those interests to be announced in a press release.  The authors may think industry sponsorship does not create a conflict of interest, but much evidence strongly suggests that it does (I reviewed that evidence in my book, Unsavory Truth).

Nov 16 2020

Industry-funded studies of the week: blueberries—again!

Thanks to Lisa Young for sending this announcement: New Research Examines Blueberries’ Positive Impact in Men with Type 2 Diabetes. 

I am already on record as saying that I love blueberries, but I wish they weren’t marketed as superfoods.  All fruits, vegetables, nuts, and grains provide nutrients and fiber.  That makes all of them worth eating for their nutrition-and-health value as well as their taste.  Singling out one or another makes no sense to me, but I’m not in the business of selling one rather than another.  Because similar results would be expected from studies of many other fruits, I put this one in the category of marketing research.

Effect of Blueberry Consumption on Cardiometabolic Health Parameters in Men with Type 2 Diabetes: An 8-Week, Double-Blind, Randomized, Placebo-Controlled Trial.  Kim S Stote, Margaret M Wilson, Deborah Hallenbeck, Krista Thomas, Joanne M Rourke, Marva I Sweeney, Katherine T Gottschall-Pass, Aidar R Gosmanov.  Current Developments in Nutrition, Volume 4, Issue 4, April 2020, nzaa030. 

Conclusion: “Consumption of 22 g freeze-dried blueberries for 8 wk may beneficially affect cardiometabolic health parameters in men with type 2 diabetes.”

Funding:  “Supported by the US Highbush Blueberry Council (to KSS, MMW, and ARG) and by resources and the use of facilities at the Stratton VA Medical Center, Albany, NY, USA.  Author disclosures: KSS, MMW, and ARG received intervention products from the US Highbush Blueberry Council. All other authors report no conflicts of interest.  The US Highbush Blueberry Council supplied the funds to conduct the study but was not involved in the design, implementation, analysis, or interpretation of data.

Comment:  The funder does not have to be involved.  Everyone knows funders are not interested in funding research that might produce results unfavorable to their product.  Freeze-dried blueberries sound like medicine.  I’d rather eat the real things.

Aug 27 2020

Odd items I’ve been saving up

For no particular reason other than curiosity, I’ve been hanging on to these items.  This feels like a good time to share them.