Currently browsing posts about: Sponsored-research

Thanks to Bradley Flansbaum for sending this one from a journal not on my usual reading list: “In persons with constipation or IBS-C, kiwifruit vs. psyllium increased spontaneous bowel movements.”

I like the way this press release gets right to the point.

An industry-funded randomized trial assessed the effect of daily consumption of kiwifruit versus psyllium on GI function and comfort in 184 adults who were healthy, had functional constipation (FC), or met Rome III diagnostic criteria for constipation-predominant irritable bowel syndrome (IBS-C).

The study: Consumption of 2 Green Kiwifruits Daily Improves Constipation and Abdominal Comfort—Results of an International Multicenter Randomized Controlled Trial.  The American Journal of Gastroenterology ():10.14309/ajg.0000000000002124, January 9, 2023. | DOI: 10.14309/ajg.0000000000002124.

Authors: Gearry, Richard MD, PhD; Fukudo, Shin MD, PhD; Barbara, Giovanni MD; Kuhn-Sherlock, Barbara PhD; Ansell, Juliet PhD; Blatchford, Paul PhD; Eady, Sarah MSc; Wallace, Alison PhD; Butts, Christine PhD; Cremon, Cesare MD; Barbaro, Maria Raffaella PhD; Pagano, Isabella MD; Okawa, Yohei PhD; Muratubaki, Tomohiko PhD; Okamoto, Tomoko PhD; Fuda, Mikiko MS; Endo, Yuka MD; Kano, Michiko MD, PhD; Kanazawa, Motoyori MD, PhD; Nakaya, Naoki PhD; Nakaya, Kumi PhD; Drummond, Lynley BTech (Hons)

Summary of the study

Methods: Participants included healthy controls (n = 63), patients with functional constipation (FC, n = 60), and patients with constipation-predominant irritable bowel syndrome (IBS-C, n = 61) randomly assigned to consume 2 green kiwifruits or psyllium (7.5 g) per day for 4 weeks, followed by a 4-week washout, and then the other treatment for 4 weeks. The primary outcome was the number of complete spontaneous bowel movements (CSBM) per week.

Results: Consumption of green kiwifruit was associated with a clinically relevant increase of ≥ 1.5 CSBM per week (FC; 1.53, P < 0.0001, IBS-C; 1.73, P = 0.0003) and significantly improved measures of GI comfort (GI symptom rating scale total score) in constipated participants (FC, P < 0.0001; IBS-C, P < 0.0001).

Conclusion: This study provides original evidence that the consumption of a fresh whole fruit has demonstrated clinically relevant increases in CSBM and improved measures of GI comfort in constipated populations. Green kiwifruits are a suitable dietary treatment for relief of constipation and associated GI comfort.

Financial support: Zespri International Ltd. was the principal sponsor and reviewed, approved, and funded the study design. The New Zealand study center trial was jointly funded by a grant from the New Zealand government (Contract C11X1312) and the sponsor company, Zespri International Ltd. In Italy and Japan, Zespri International Ltd. was the sole funder for each study center trial. The funder did not contribute to the study design or data analysis.

Potential competing interests: J.A. and P.B. are employed by Zespri International who part-funded the study. R.G. and L.D. sit on the Science Advisory Board, have received travel and research grants from Zespri International. SF and GB have received research travel grants from Zespri International.

Comment:  Can you guess what Zespri International sells?  Go on.  Take a wild guess.  I’ll admit it.  I’d go for kiwi over psyllium every time.  But we are talking here about an average improvement of 1.5 bowel movements a week, which may or may not be clinically meaningful..  I do give the authors credit for claiming a benefit for “fresh whole fruit,” not specifically kiwifruit.  The study didn’t compare kiwi to other fruits (and why would it, given the kiwi fruit sponsor).  But overall, this is yet another study done for marketing far more than scientific purposes.

Thanks to reader Maira Bes-Rastrollo at the University of Navarra in Spain (and whose work I greatly admire) for this one.

The Relationship of Ready-to-eat Cereal Intake and Body Weight in Adults: A Systematic Review of Observational Studies and Controlled Trials.   Lisa M Sanders, Mary R. Dicklin, Yong Zhu, Kevin C. Maki.  Advances in Nutrition https://doi.org/10.1016/j.advnut.2023.05.001

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.

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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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 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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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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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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