Currently browsing posts about: Nuts

The study: Investigating walnut consumption and cognitive trajectories in a representative sample of older US adults.  Nicholas J. Bishop and Krystle E. Zuniga.  Public Health Nutrition , Volume 24 , Issue 7 , May 2021 , pp. 1741 – 1752.

Purpose: To estimate the association between whole walnut intake and cognitive change in a sample of 3632 US adults aged 65 years and older.

Method:  This was a secondary analysis of dietary data and health outcome from the Health and Retirement Study and Health Care and Nutrition Study.

Conclusions: “We identified an association between walnut consumption and cognitive function in older adults, although we did not find that walnut consumption was protective against age-related cognitive decline.”

Financial support: This research was funded by the California Walnut Commission.

Comment: Eating walnuts tracks with cognitive function in this sample, but has no particular effect on it.  As I read them, the conclusions put a positive spin on a null finding, a classic example of “interpretation bias.”  The Walnut Commission paid for the study and this interpretation helps to sell walnuts.  I think walnuts are great but wish the California Walnut Commission would stay out of this kind of marketing research.

The Peanut Institute is working overtime to convince you to eat more peanuts.

Disclaimer: I love peanuts and think they are great to cook with and make an excellent snack—peanut butter too—but I see no need to overhype them, as this press release does.

Research Reveals Daily Dose of Peanuts Delivers Body and Mind Benefits: Americans Encouraged to Pause for Peanuts…Peanuts are a superfood so just a small amount can fend off mid-morning hunger, help eliminate the afternoon slump and deliver much-needed brainpower.

“Superfood,” I must remind you, is a marketing term.  It has no nutritional meaning.  All fruits, vegetables, grains, beans, and, yes, nuts, have nutritional value.  On that basis, all plant foods are “superfoods.”

The press release makes these claims, and provides references for most of them:

• Regular peanut consumption has been associated with a reduced risk of heart disease, diabetes and numerous kinds of cancer.
• An ounce of peanuts packs more protein than any other nut.
• Peanuts stimulate peptide YY, a hormone that decreases appetite.
• Peanuts also have a low glycemic index that helps stabilize blood sugar to prevent the feeling of ‘crashing’ in the afternoon.
•  A single serving of peanuts is packed with 19 vitamins and minerals, including the antioxidant resveratrol, which has been shown to increase blood flow to the brain.
• Peanuts also contain high levels of niacin and are a good source of vitamin E – two nutrients that support brain health and have long been known to protect against Alzheimer’s disease and age-related cognitive decline
• Eating peanuts twice a week can reduce the risk of premature death by 12% and reduce the risk for certain cancers, including colorectal, gastric, pancreatic and lung cancers.
• Regular consumption can also reduce the risk of death due to heart disease by 24%, respiratory disease by 16%, infections by 32% and kidney disease by 48%.

As I read the research on peanuts, it associates eating nuts of all types with good health.   Is there something distinctive about peanuts as compared to other kinds of nuts?

I doubt it—all nuts are worth eating.

A basic prinicple of nutrition is to vary food intake.  You love peanuts (as I do)?  Eat them, but go easy on the salt.

I was fascinated to see this ad in the June 8 & 15 issue of the New Yorker inside the back cover:

I like pistacchios, but never thought of them as a protein source and in any case so what?  Protein is anything but lacking in American diets.

I went right to the website, AmericanPistachios.org: “Breaking News: Pistachios are a complete protein.”  I read more: A study shows that pistachios have all 9 essential amino acids.

Here’s the study:

I assumed that the study was paid for by the pistachio association, but if so, the funding was well laundered.  The disclosure statement says: “This study was funded by a Specialty Crop Grant from the US Department of Agriculture.”  The USDA supports pistachio marketing.

OK.  Here’s why I think this ad is absurd.

• Americans consume roughly twice the amount of protein needed.
• Most food proteins, even those from plants, contain all 9 essential amino acids.
• Pistachios are already known to contain the essential amino acids (see the USDA food composition data base).
• 100 grams of pistachios contain 21 grams of protein BUT also 572 calories.
• Other nuts have all those amino acids too (see composition data for walnuts, for example).

I suppose it’s good to educate New Yorker readers about how plants have protein—they do!—but the emphasis on protein makes no nutritional sense.

The Pistachio trade association must think whatever this ad costs is worth the expense.*  Let’s hear it for marketing!

*What does it cost?  This depends on the size of the market—the circulation in a particular area—which can vary from one borough of New York to the whole country, and must be highly negotiable.

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 Trial.  Albert 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!

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?

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.

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.

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?