Currently browsing posts about: Fruit

Every now and then a study comes out that I just love.

Two apples a day lower serum cholesterol and improve cardiometabolic biomarkers in mildly hypercholesterolemic adults: a randomized, controlled, crossover trial.

At last, scientific proof of what we’ve always been taught.

Well, two apples, but OK.

Also OK, who paid for this?

Supported in part by AGER (Agribusiness and research) grant no. 2010-2119 funding the project “Apple fruit quality in the post-genomic era, from breeding new genotypes to post-harvest: nutrition and health.”

AGER is an Italian foundation devoted to promoting Italian agribusiness, supported, it says, by banking foundations.

I’ll take that at face value and enjoy the research.

The study: Matthews LG, Smyser CD, Cherkerzian S, Alexopoulos D, Kenley J, Tuuli MG, et al. (2019) Maternal pomegranate juice intake and brain structure and function in infants with intrauterine growth restriction: A randomized controlled pilot study. PLoS ONE 14(8): e0219596.

The findings (my emphasis): “There were no group differences in brain injury, metrics or volumes. However, treatment subjects displayed reduced diffusivity within the anterior and posterior limbs of the internal capsule compared with placebo. Resting state functional connectivity demonstrated increased correlation and covariance within several networks in treatment subjects, with alterations most apparent in the visual network in per-protocol analyses. Direct effects on health were not found.

Conclusion: In conclusion, maternal pomegranate juice intake in pregnancies with known IUGR was associated with altered white matter organization and functional connectivity in the infant brain, suggesting differences in brain structure and function following in utero pomegranate juice exposure, warranting continued investigation.

Funding: This work was supported by National Institute of Health Grants R01 HD29190 (D. M. Nelson), K02 NS089852 (C.D. Smyser), U54 HD087011 and P30 HD062171 (T.E. Inder), The Foundation for Barnes-Jewish Hospital (D. M. Nelson) and an unrestricted gift to Washington University School of Medicine from POM Wonderful, Los Angeles, CA. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Comment: This is a classic example of interpretation bias.  Studies of bias associated with industry funding find that it shows up mostly in the framing of the research question or in the interpretation, as this one demonstrates.  The study did not find anything significant but concluded that drinking pomegranate juice during pregnancy is good for the growing fetus.

Bottom line: Fruit juices (of any kind) are good for health as long as volumes are small.  Eating the fruit itself is better–less sugar, more fiber.

I get letters like this from food trade associations all the time.  Here is the latest:.

The U.S. Highbush Blueberry Council has issued a request for research proposals (RFP) for which it offers grants ranging from $75,000 to $300,000 (or larger).

Here’s the get-go bias point (my emphasis):

The goal of our research funding is to provide initial funds, or additional funds, to explore blueberry health benefits.

The Council wants research to demonstrate benefits.  Of course it does.  These will be useful for marketing.

A priority for funding will be given to human clinical studies however the committee is also interested in further investigation of possible health benefits for pet or performance animals including dogs, cats and horses.

If the proposal is unlikely to demonstrate benefit, it won’t be funded.

That’s why I consider industry-funded research to be about marketing, not science.

Effect of Montmorency tart cherry juice on cognitive performance in older adults: a randomized controlled trial, Sheau C. Chai,, et al. Food Funct., 2019,10, 4423-4431.

Method: In this randomized controlled trial, 37 adults between the ages of 65–80 with normal cognitive function were recruited and randomly assigned to consume two cups of Montmorency tart cherry juice for 12 weeks.

Results: The within-group analysis showed that the visual sustained attention (p < 0.0001) and spatial working memory (p = 0.06) improved after the 12-week consumption of tart cherry juice compared with corresponding baseline values. Daily tart cherry juice consumption may improve cognitive abilities.

Conclusion: Our study demonstrated that daily intake of Montmorency tart cherry juice may help improve subjective memory and cognitive abilities in older adults as evidenced by increased contentment with memory, improved visual sustained attention and spatial working memory, and reduced movement time and total errors made on new learning tasks in older adults. T

Acknowledgements: The present study was supported by the Cherry Research Committee of the Cherry Marketing Institute, a non-profit organization. Tart cherry concentrates were provided by the Cherry Marketing Institute. Funders had no role in the study design, data collection, data analysis or interpretation, or writing of the manuscript.

Comment: I love cherries—a joy of summer—and wouldn’t it be wonderful if eating them was all you had to do to prevent cognitive decline.  Are cherries better than any other fruit or vegetable for this purpose?  This study did not examine that question but eating a healthy diet is always a good idea.  As for funders having no role, they don’t have to.  The mere fact that they funded this study skews the research question, as much evidence demonstrates (I reviewed this evidence in Unsavory Truth).

I love blueberries and grow two different kinds on my 12th-floor Manhattan terrace, both delicious if I can get to them before the voracious birds do.

I wish the blueberry industry could just accept delicious and leave it at that, but no such luck.  It is desperate to get research it can use to promote blueberries as a superfruit (I wrote about the history of blueberry-funded research in Unsavory Truth).

Here’s the latest.

The study: Blueberries improve biomarkers of cardiometabolic function in participants with metabolic syndrome—results from a 6-month, double-blind, randomized controlled trial.  Peter J Curtis, et al. Am J Clin Nutr 2019;109:1535–1545.

Method: Participants were fed powdered blueberries equivalent to a half or full cup a day, compared to placebo.

Conclusions: Despite insulin resistance remaining unchanged we show, to our knowledge, the first sustained improvements in vascular function, lipid status, and underlying NO [nitric oxide] bioactivity following 1cup blueberries/d. With effect sizes predictive of 12–15% reductions in CVD risk, blueberries should be included in dietary strategies to reduce individual and population CVD risk.

Funder: Supported by the US Highbush Blueberry Council (USHBC) with oversight from the USDA and the Biotechnology and Biological Sciences Research Council (BBSRC, UK). AC and ERB both act as advisors to the USHBC grant committee. The funders of the study had no role in study design, data collection, data analysis, data interpretation, or writing of the report.

Comment: The press picked this one up:  “Study: Blueberries benefit heart health.”  This study used powdered blueberries.  Trust me, the fresh ones are much better.  You can tell this is an industry-funded study because the published study is open access, which somebody has to pay for—a clue that it is about marketing.  And what about the comment that funders had no influence?  They didn’t have to.  The study did not compare blueberries to any other fruits.  The science here provides some interesting information about how anthocyanins in this fruit might work, but wouldn’t they work the same way in any other fruit?  Are blueberries the only fruit that contains these particular anthocyanins?   This questions suggest that this study is not about the science, it is about demonstrating that there is something special about blueberries.  Dietary advice?  Eat whatever fruits you like.  And vegetables.  And nuts.  They all have something good about them.

I don’t know whether to laugh or cry when I hear things like this.  According to a report from the Associated Press, the FDA plans to follow the Trump administration’s deregulaory agenda by getting rid of the standard of identity rules for frozen cherry pies.

The rules currently require commercial frozen cherry pies to be filled with “mature, pitted, stemmed cherries that are fresh, frozen, and/or canned,” to contain at least 25% cherries by weight, and to have no more than 15% of the cherries with blemishes.

In October, then-FDA Commissioner Scott Gottlieb sent out this tweet.

In a June email, the FDA said it planned to revoke the standard for frozen cherry pies in April. It has kept its word.

My questions:

• Without the standard of identity, are we likely to have more or fewer cherries in frozen cherry pie?  [Want to make a bet?  I’m guessing fewer].
• What lobbying group got the FDA to do this, and why did the FDA agree?
• Did ex-Commissioner Gottlieb really consider this a top priority for FDA? [If so, we are in even worse trouble than even I imagined].

I’m stuck on regulatory priority.  Food safety, anyone?

As for the origins of the cherry pie count, see this excellent piece in the Washington Post by historian Xaq Frohlich.

In my book, Unsavory Truth, I mention that I often receive letters from food trade associations requesting research proposals aimed at proving the benefits of their products.

I point out that there is a big difference between calling for research to prove benefits, and open-ended basic research aimed at discovering what the actual effects might be.

Here is a delicious example from the Cherry Research Committee of the Cherry Marketing Institute:

All proposed research should be hypothesis-driven, and would strive to establish an association or to document a direct relationship between the consumption of tart cherry phytonutrients (when consumed as whole tart cherries or processed tart cherry products) and reduced risk, prevention, or improved treatment of a disease or condition of significant public interest. The study design should also examine a possible
cellular/molecular mechanism of the treatment effects.

And here’s an example of cherry-benefit research in action:

Title: Effects of Tart Cherry Juice on Biomarkers of Inflammation and Oxidative Stress in Older Adults.  Chai SC, Davis K, Zhang Z, Zha L, Kirschner KF.  Nutrients. 2019 Jan 22;11(2). 

Conclusion: “The present study suggests that the ability of tart cherry juice to reduce systolic BP [blood pressure] and LDL cholesterol [the bad kind], in part, may be due to its anti-oxidative and anti-inflammatory properties. Larger and longer follow-up studies are needed to confirm these findings.”

Grant support: Cherry Research Committee of the Cherry Marketing Institute

Comment:  As the press release explains:

Montmorency tart cherry juice helped lower systolic blood pressure and LDL or “bad” cholesterol in older adults by reducing certain biomarkers of inflammation and oxidative stress in older adults, according to a new study published in Nutrients. Larger and longer follow-up studies are needed to confirm these findings.

I posted another cherry-funded study early in December.

I love cherries.  They are delicious, but this is marketing research, not basic science.

…Thanks to Casey Palmer for sending all this.