Currently browsing posts about: Fruit

The study:  Daily consumption of cranberry improves endothelial function in healthy adults: a double blind randomized controlled trial.  Christian Heiss,  et al.  Food & Function.  2022;7.  DOI https://doi.org/10.1039/D2FO00080F

Objective: To investigate the vascular effects of acute and daily consumption of freeze dried whole cranberry in healthy men and how effects relate to circulating cranberry (poly)phenol metabolites.

Methods: A double-blind, parallel-group, randomized controlled trial was conducted in 45 healthy male adults randomly allocated to 1 month daily consumption of either cranberry (9 g powder solubilized in water equivalent to 100 g of fresh cranberries, 525 mg total (poly)phenols) or control (9 g powder, no (poly)phenols).

Results: Cranberry consumption significantly increased FMD [flow-mediated dilation].

Conclusions: Acute and daily consumption of whole cranberry powder for 1 month improves vascular function in healthy men and this is linked with specific metabolite profiles in plasma.

Funding: This study was funded by the Cranberry Institute and by the Research Committee of the Medical Faculty of Heinrich-Heine University Dusseldorf (grant number 9772574). The authors also acknowledge a Susanne Bunnenberg Heart Foundation grant to Dusseldorf Heart Centre.

Comment: I like cranberries.  Of course I consider them healthy to eat.  All fruits have health benefits.

But cranberry powder?

And cranberries are tart,; they need sugar.  Ocean Spray’s cranberry sauce recipe calls for one cup of sugar added to 12 ounces of cranberries.

Moderation, please!

A reporter sent me this emailed announcement from a publicist for Dole hoping to generate storeis about how bananas can relieve stress.   Your problems are solved!

Hi —

Hope all is well! Following up on the below story. In honor of National Banana Day on April 20 and April’s designation as Stress Awareness Month, Dole Food Company is sharing 10 recipes that celebrate the iconic yellow fruit and the science-backed link between bananas and the alleviation of stress.

Would love your consideration for coverage!

What do bananas do for stress?

 “Bananas contain vitamin B6, which is involved in the creation of feel-good neurotransmitters, and research suggests that they can also reduce inflammation and oxidative stress levels. Another study found that foods like bananas that contain prebiotics may also promote more restful sleep.”

And that’s not all:

Fruit lovers may go bananas for the following recipes as they are not only delicious, but are either vegetarian, vegan and/or gluten-free. The recipes are the latest installment of “Healthier by Dole,” the produce giant’s ongoing monthly healthier recipe series to encourage eating that is good for both the mind and the body.

The press release is here.

Comment: I’m all for eating fruit but are bananas better than any other kind for relieving stress?  None of this is based on studies that compare one fruit to another.  All fruits contain B vitamins and other good things.  Eat the ones you like!

Thanks to Georgene Grover for sending this one, with this comment: “What about this? Ten prunes a day seems excessive!”

The study:  The Role of Prunes in Modulating Inflammatory Pathways to Improve Bone Health in Postmenopausal Women.  Janhavi J Damani, Mary Jane De Souza, Hannah L VanEvery, Nicole CA Strock, and Connie J Rogers. Adv Nutr 2022;00:1–17.

Purpose:  Prunes (dried plums; Prunus domestica L.) have been studied as a potential whole-food dietary intervention to mitigate bone loss in preclinical models of osteoporosis and in osteopenic postmenopausal women.

Method: This is a review of previous studies.  It summarizes findings from preclinical and clinical studies that have assessed the effect of prunes on oxidative stress, inflammatory mediators, and bone outcomes. Most of the studies that reported effects required 100 grams per day of prunes (about 10 per day).

Conclusion: Overall, evidence from in vitro, preclinical studies, and limited clinical studies suggests the potential role of prunes in ameliorating bone loss.

Funding and COI: Supported by the California Prune Board provided funding to MJDS and CJR. Publication funds came from the Hershey Company endowment, Department of Nutritional Sciences, Penn State University. California Dried Plum Board (grant no. 100804). Author disclosures: CJR is member of the Nutrition Advisory Panel for the California Dried Plum Board. The other authors report no conflicts of interest.

Comment: This is a standard industry-funded paper with a predictable outcome.  As far as I can tell, every food trade association is funding research that can help with marketing.  Even prunes.

Prunes are fine, but studies of one food don’t really tell you anything about diets as a whole.  Eat prunes if you like them.  Ten prunes means ten plums.  Seems like a lot, no?

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.

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 Vitro.  Martin Foltz, Alicia Christin Zahradnik, Pieter Van den Abbeele, Jonas Ghyselinck, Massimo 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.

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:

And off:

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.

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.

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.