by Marion Nestle

Currently browsing posts about: Nuts

Feb 17 2020

Industry-funded study of the week: nuts and erectile dysfunction

I swear I’m not making this up.

The study: Effect of Nut Consumption on Erectile and Sexual Function in Healthy Males: A Secondary Outcome:  Analysis of the FERTINUTS Randomized Controlled TrialAlbert Salas-Huetos, Jananee Muralidharan, Serena Galiè, Jordi Salas-Salvadó, and Mònica Bulló.  Nutrients 2019, 11(6), 1372; https://doi.org/10.3390/nu11061372.

The conclusion: “Including nuts in a regular diet significantly improved auto-reported orgasmic function and sexual desire.”

The funder: “This work was partially supported by the International Nut and Dried Fruit Council (INC)…INC is a non-profit entity registered at the Register of Foundations of Catalonia, Spain. Nuts were supplied by Crisolar, Spain.

Comment: I love these results, and have no doubt that the funder did too.  I can only imagine the ads based on this study.  News accounts too (here’s a good one from London’sDaily Mail).

The results were so interesting that a separate group reviewed the data and confirmed that the numbers led to the same results.  This is not surprising.  Most studies of bias in research show that it turns up mainly in the way the research question is framed or in the interpretation of the data, not in the conduct of the science or collection of data.

Hey guys: have problems?  Eat a mixture of raw walnuts, almonds, and hazelnuts and collect your own data!

Feb 11 2020

California’s almond crop: the bee business

Almonds are great foods, and almond trees are beautiful, especially when in bloom (a lovely thought on a bleak winter’s day).

To produce almonds, the blossoms have to be pollinated, a job done by bees.

The bees don’t just appear spontaneously.  Getting them to orchards is a for-profit business enterprise.  

Most varieties of almond trees require cross-pollination – the transfer of pollen from one tree variety to another – to produce any nuts at all….Roughly 1 million acres of almond trees collectively bloom over a three-week period every February, creating spectacular scenic views but also putting enormous pressure on the farmers to pollinate them quickly. Each almond acre requires roughly two honey bee hives, each of which typically houses one colony of about 20,000 bees. With 2 million hives needed, that’s well more than half of the total U.S. hive population.

Unfortunately, trucking beehives around from one orchard to another is hard on the bees.

As The Guardian recently put it, using bees to fertilize almond orchards is “Like sending bees to war.” and “the truth behind your almond milk obsession” is deadly.

A recent survey of commercial beekeepers showed that 50 billion bees – more than seven times the world’s human population – were wiped out in a few months during winter 2018-19. This is more than one-third of commercial US bee colonies, the highest number since the annual survey started in the mid-2000s.

Beekeepers attributed the high mortality rate to pesticide exposure, diseases from parasites and habitat loss. However, environmentalists and organic beekeepers maintain that the real culprit is something more systemic: America’s reliance on industrial agriculture methods, especially those used by the almond industry, which demands a large-scale mechanization of one of nature’s most delicate natural processes.

FoodNavigator USA.com has issued a Special Report on this topic: “Bee friendly?  Pollinating California’s almond crop.”  It gives the almond industry’s view of the bee problem and its various causes.

The truth, as always, is more complicated, claims Dr Josette Lewis, director of agricultural affairs at the Almond Board of California, who likes to preface any conversation on this topic with the observation that almond growers are pretty motivated when it comes to ensuring honey bees are healthy and happy, given that it costs them almost $400/acre (two hives at c. $200 apiece) to hire these furry little pollinators upon which the success of their crop entirely depends. (To put this in perspective, it cost an average of $160/acre—two hives at c. $80 apiece – in 2005).

There is a “Bee-Friendly Farming” initiative among almond growers, but only about 10% are using it.

Regulation, anyone?

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Feb 10 2020

Industry-funded campaign of the week: Walnuts

A headline in FoodNavigator.com got my attention: “Heart-healthy walnuts could be the next big meat alternative as campaigns build on plant-based trend.

Hoping to exponentially increase consumers’ already growing interest in walnuts, the California Walnut Board today is launching a two-prong marketing effort that will promote the nut’s health benefits and versatility.

The prongs are in-store promotions and a global marketing campaign—in nine countries no less—emphasizing how you only need to eat three handfuls a week to get their health benefits.

The article notes that the health benefits are based on published research.  Alas, it fails to mention that the cited study was ” funded by The California Walnut Commission.”

The study:  Walnuts and Vegetable Oils Containing Oleic Acid Differentially Affect the Gut Microbiota and Associations with Cardiovascular Risk Factors: Follow-up of a Randomized, Controlled, Feeding Trial in Adults at Risk for Cardiovascular Disease.  Alyssa M Tindall, Christopher J McLimans, Kristina S Petersen, Penny M Kris-Etherton, Regina Lamendella.  The Journal of Nutrition, nxz289, https://doi.org/10.1093/jn/nxz289.  

Its conclusion: “…gut microbiota may contribute to the health benefits of walnut consumption in adults at cardiovascular risk.”

The California Walnut Commission has been diligent in funding studies reporting benefits from walnut consumption.  Here’s another one:

The study: Effect of a 2-year diet intervention with walnuts on cognitive decline.  The Walnuts And Healthy Aging (WAHA) study: a randomized controlled trial.  Aleix Sala-Vila, Cinta Valls-Pedret, Sujatha Rajaram, Nina Coll-Padrós, Montserrat Cofán, Mercè Serra-Mir, Ana M Pérez-Heras, Irene Roth, Tania M Freitas-Simoes, Mónica Doménech, Carlos Calvo,1,2 Anna López-Illamola, Edward Bitok, Natalie K Buxton, Lynnley Huey, Adam Arechiga, Keiji Oda, Grace J Lee, Dolores Corella, Lídia Vaqué-Alcázar, Roser Sala-Llonch, David Bartrés-Faz, Joan Sabaté, and Emilio Ros.  Am J Clin Nutr 2020;00:1–11.

Conclusions:Walnut supplementation for 2 y had no effect on cognition in healthy elders. However, brain fMRI and post hoc analyses by site suggest that walnuts might delay cognitive decline in subgroups at higher risk.”

Conflicts of interest: AS-V, SR, JS, and ER have received research funding through their institutions from the California Walnut Commission, Folsom, CA, USA. JS and ER were nonpaid members of the California Walnut Commission Scientific Advisory Council. ER was a paid member of the California Walnut Commission Health Research Advisory Group. JS has received honoraria from the CaliforniaWalnut Commission for presentations. AS-V has received support from the CaliforniaWalnut Commission to attend professional meetings. All other authors report no conflicts of interest.

Comment: Some of the authors of this study work at Loma Linda, a university run by vegetarian Seventh-Day Adventists.  As is unusual for industry-sponsored studies, this one found no delay in cognitive decline among older people eating walnuts.  But the study’s conclusions spin the results to suggest that walnuts might, in fact, delay cognitive decline in higher risk subgroups—an interpretation bias.

Walnuts are good foods and eating them instead of candy or other high calorie junk-food snacks makes sense.  Are walnuts better for you than any other nut?  This study does not address that question.  Studies funded by walnut trade associations have one and only one purpose: marketing walnuts.

As a reminder, I discussed issues related to sponsored research—including why the conduct of the science is not the problem with these studies—in my book, Unsavory Truth: How Food Companies Skew the Science of What We Eat.

Sep 23 2019

Industry-funded study of the week: Almonds

Title: Almond Consumption and Risk Factors for Cardiovascular Disease:A Systematic Review and Meta-analysis of Randomized Controlled Trials. Lee-Bravatti MA, et al.  Adv Nutr. 2019;00:1–13

Method: The authors selected studies that had compared lab values of adults who consumed almonds with those who did not.  They found significant reductions in some—but not all—CVD risk factors among the almond eaters.  The almond eaters, for example, had lower total cholesterol levels and lost weight during the trials.

Conclusion: “Almond consumption may reduce the risk of CVD by improving blood lipids and by decreasing body weight and apoB [apolipoprotein B].”

Funding: “Supported by the Almond Board of California…The funder did not have a role in the study selection, quality assessment, data synthesis, or manuscript preparation.”

Author disclosures:  GR was a consultant for Porter Novelli; EJJ received funds from the Almond Board of California for a clinical trial at the time of the study. MAL-B, JW, EEA, and LK, no conflicts of interest.

Comment: I like nuts and am especially partial to marcona almonds, but I wish the almond industry would stop trying to prove that almonds can perform health miracles. I can easily see why substituting almonds for ultraprocessed junk foods would help reduce markers of CVD risk, calories, and weight: people who eat junk food consume more calories and are more likely to be obese.  This study set a standard of 42.5 grams of almonds a day, roughly 1.5 ounces  and 200 calories.  But are almonds superior to other nuts?  The Walnut Commission would argue otherwise, as would the Pecan Growers’ Association.  The Almond Board may say it has nothing to do with the study, but it doesn’t have to.  Its funding is sufficient to exert influence even if investigators don’t realize it, as I discuss in Unsavory Truth.

Jul 22 2019

Industry-funded study of the week: Walnuts

Replacing Saturated Fat With Walnuts or Vegetable Oils Improves Central Blood Pressure and Serum Lipids in Adults at Risk for Cardiovascular Disease: A Randomized Controlled‐Feeding Trial.  Alyssa M. Tindall, et al. Journal of the American Heart Association. 2019;8:May 7, 2019.

Conclusions: “Replacing saturated fatty acids (FAs) with 57 to 99 g/d of walnuts for 6 weeks reduced central diastolic blood pressure compared with a diet similarly low in saturated FAs but with lower α‐linolenic acid content…This study represents a feasible food‐based approach for replacing saturated FAs with unsaturated FAs (including α‐linolenic acid) from walnuts and vegetable oils, demonstrating that relatively small dietary changes can reduce cardiovascular risk.

Funding: This study was funded by the California Walnut Commission…The California Walnut Commission provided funds for the research conducted. The commission’s staff was not involved with any aspects of conducting the study, analyzing the data, or interpreting the results reported in this article.

Comment: Walnuts, like pretty much all other nuts and seeds, contain healthy fats and other nutrients.  When substituted for unhealthier foods, they would be expected to demonstrate improvements.  This study contributes no new information and there is only one reason to do it: marketing (as I discuss in Unsavory Truth).  The California Walnut Commission wants you to eat more walnuts.  Trade associations or producers of pecans, macadamia nuts. pistachios, almonds, peanuts, hazelnuts, and any other nut you can think of have the same goal.  Do they all have to do this kind of research?  Apparently so.

Mixed nuts, anyone?

Jun 17 2019

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

Pistachio consumption modulates DNA oxidation and genes related to telomere maintenance: a crossover randomized clinical trial.
Silvia Canudas, Pablo Hernández-Alonso, Serena Galié, Jananee Muralidharan, Lydia Morell-Azanza, Guillermo Zalba, Jesús García-Gavilán,1Amelia Martí, Jordi Salas-Salvadó, and Mònica Bulló.  Am J Clin Nutr 2019;0:1–8.

Conclusions: “Chronic pistachio consumption reduces oxidative damage to DNA and increases the gene expression of some telomere-associated genes. Lessening oxidative damage to DNA and telomerase expression through diet may represent an intriguing way to promote healthspan in humans, reversing certain deleterious metabolic consequences of prediabetes.”

Funding: “The Western Pistachio Association( USA) and Paramount Farms [which grows pistachios and is owned by POM Wonderful] supported the trial… None of the funding sources played a role in the design, collection, analysis, or interpretation of the data, or in the decision to submit the manuscript for publication.”

Comment: I love pistachios.  Like other seeds and nuts, pistachios provide healthy fats and other nutrient along with their calories.  POM Wonderful is notorious for spending fortunes on research to prove the health benefits of the nuts and fruits it produces.  These are, of course, high on the recommended-for-health list.  Therefore, as I discuss in Unsavory Truth, such studies are about marketing, not science.

Jan 21 2019

Industry-funded request of the week: prove peanuts healthy

Peanuts are delicious when freshly roasted—I always keep some on hand—and they are highly nutritious, despite their calories.

But the peanut industry must not think sales are high enough (oh those sales-inhibiting peanut allergies).

Its trade group, The Peanut Institute, has issued a Call for Research Proposals.

We are currently requesting human peanut nutrition research proposals with an emphasis on the effect of consuming peanuts, peanut butter, and other peanut products on: (1) cognition/brain health, (2) chronic disease risk and outcomes, (3) diet quality, and (4) gut microbiome in various populations. Other research areas that increase the understanding of peanut consumption and human health are encouraged. All novel and noteworthy proposals that advance the health and wellness message of peanuts will be reviewed [my emphasis].

The Peanut Institute is not interested in funding open-ended research exploring the effects of peanuts on health.

Instead, it intends only to consider proposals designed to prove benefits.  This is marketing research, not basic science.

As I demonstrated in Unsavory Truth: How Food Companies Skew the Science of What We Eat, the basic observation is this: industry-funded research almost always favors the sponsor’s product.

I discuss similar requests from other trade groups in that book.  Guess what.  The funders usually get what they ask for.

Dec 17 2018

Industry-funded study of the week: Hazelnuts

My most recent book, Unsavory Truth: How Food Companies Skew the Science of What We Eat, provides many examples of industry-funded studies with results favorable to their sponsor’s marketing interests.  This “funding effect” shows up mostly in the framing of the research question.

Here is this week’s example, one so explicitly designed to sell hazelnuts that you can guess the funder from the title.

The study: Alexander J Michels, Scott W Leonard, Sandra L Uesugi, Gerd Bobe, Balz Frei, and Maret G Traber.  Daily Consumption of Oregon Hazelnuts Affects α-Tocopherol Status in Healthy Older Adults: A Pre-Post Intervention Study. J Nutr 2018;148:1924–1930.

Methods: Subjects consumed ∼57 g hazelnuts/d and were asked to refrain from eating all other nuts, seeds, and many vitamin E– and magnesium-rich food items.

Results: Hazelnut consumption increased concentrations of the urinary α-tocopherol [Vitamin E] metabolite…In addition, hazelnut consumption increased serum concentrations of magnesium.

Conclusions: Consuming hazelnuts improves a biomarker of vitamin E status in older adults…thus, hazelnuts should be considered as part of a healthy dietary pattern.

Funding: Supported by the Oregon State University Foundation (to BF) and the Hazelnut Marketing Board of Oregon (to BF).

My Comment: I love hazelnuts for their crunch and how they taste.  They have nutrients.  If you don’t eat anything else with vitamin E or magnesium, eating them will of course increase your consumption of those nutrients, and you don’t need a clinical trial to prove it.

That’s why I think studies like this are more about marketing than science.  A news account—although it reads like a press release–-quotes co-author Alex Michels:

Not that we think Oregon hazelnuts are much different than other sources…but now the booming crop that we have in this state finally has science behind it. Perhaps other benefits of Oregon hazelnuts are awaiting future study.