Currently browsing posts about: Nuts

I learned about this one from an article in FoodNavigator: Study: Walnut consumption linked to improved life expectancy

New research from the Harvard T.H. Chan School of Public Health funded by the California Walnut Commission has found a possible link between higher walnut consumption and increase in life expectancy among older US adults.

The article quotes the senior author:

What we’ve learned from this study is that even a few handfuls of walnuts per week may help promote longevity, especially among those whose diet quality isn’t great to begin with. It’s a practical tip that can be feasible for a number of people who are looking to improve their health, which is top of mind for many people.

Washington Post columnist Tamar Haspel tweeted about this study: “I have a pretty big beef with nutritional epidemiology, and there’s a new study on walnuts that pushes all my button[s].”

Her beefs:

• Difficulties interpreting information from food frequency questionnaires
• Complications of correcting for confounding variables (18 in this case)
• Implications of causation (“lots of talk about the cardioprotective aspects of walnuts”)
• The study was not pre-registered
• It was funded by the walnut industry

Her view (with which I concur):

• “Studies like the [sic] have helped create the mess that is nutrition advice”
• “We DO NOT have the tools to assess the health impact of specific foods.”
• “Eat a wide variety of whole-ish foods you enjoy in quantities consistent with the weight you want to be.  Eat walnuts if you like them.”

The study: Association of Walnut Consumption with Total and Cause-Specific Mortality and Life Expectancy in U.S. Adults.  Xiaoran Liu, Marta Guasch-Ferré, Deirdre K. Tobias, Yanping Li.

Method: Correlated information on dietary intake of walnuts from two large epidemiological studies  with mortality.

Conclusions: We reported that higher consumption of walnut was associated with a lower risk of all-cause mortality and CVD mortality in two large prospective studies of U.S. elder adults, especially among those with suboptimal dietary quality. We estimated a greater life expectancy at age 60 of 1.3 years in women and 1.26 years in men, among those who consumed walnuts more than 5 servings/week compared to non-consumers.

Conflicts of interest: Li has received research support from California Walnut Commission. The funder has no role in the design and conduct of the study, in the collection, analysis, and interpretation of the data, and in the preparation, review, or in the decision to publish the results. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.

Comment: In addition to Haspel’s comments, I would add that the statement that the funder had no role is difficult to evaluate.  Industry funders generally do not pay for research likely to come out with results unfavorable to their products and much evidence suggests that influence is exerted at an unconscious level.  I provide evidence for this and other observations about industry “funding effects”—observations 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—in my book, Unsavory Truth: How Food Companies Skew the Science of What We Eat.

I must also point out that walnuts are not the only nuts singled out for specific health benefits.  See, for example, “Pecan-Enriched Diets Alter Cholesterol Profiles and Triglycerides in Adults at Risk for Cardiovascular Disease in a Randomized, Controlled Trial” in a recent issue of the Journal of Nutrition.  Its sponsor was the Georgia Pecan Commission.

The bottom line: eat whatever nuts you like.

I know I’ve already posted one of these this week, but this one is too good not to share.

Let’s start with the press coverage: Snack yourself young: Study investigates the effects of daily almond consumption on wrinkles

A study by American research found that eating almonds daily reduces wrinkle severity – along with improving skin pigmentation – in postmenopausal women.

The 2021 study – published in Nutrients and funded by the Almond Board of California – expands upon findings of a 2019 study​​ that found there may be more than one reason to add almonds to a daily skin care routine.​​

And here’s the study in question: Prospective Randomized Controlled Trial on the Effects of Almonds on Facial Wrinkles and Pigmentation.  Authors: Sivamani RK, Rybak I, Carrington AE, Dhaliwal S, et al.  Nutrients. 2021; 13(3):785

This is not their first on this topic.  See: Prospective randomized controlled pilot study on the effects of almond consumption on skin lipids and wrinkles.  Author: Sivamani RK, Foolad N, Vaughn AR, Rybak I, et al   Phytother Res. 2019 Dec;33(12):3212-3217

Nor are these the first studies to link specific foods to wrinkle prevention.  I’ve written previously about a study on mangos and wrinkle prevention, sponsored—of course—by a mango trade association.

I wish companies and trade associations would stop doing studies of one food and some health outcome. Diets that contain reasonable proportions of fruits, vegetables, and whole grains are demonstrably healthy.  Can any one food really make all that much difference?

The sellers of these foods would like you to think they are “superfoods.”  Alas, no such thing exists.  But it’s a great marketing strategy.

As for sponsored research in general?

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.

By this time, a great many research studies have associated eating nuts—of any kind—with good health.  Nuts have fats and, therefore, calories (150-200 per ounce).

The nut industry would like to minimize concerns about fats and calories.  It funds research to demonstrate that nut fats are healthy (which they are) and that you don’t have to worry about the calories (which you do, depending on what else you eat).  Hence:

The study: Almond Bioaccessibility in a Randomized Crossover Trial: Is a Calorie a Calorie?  Nishi SK, et al.  Mayo Clinic Proceedings, 2021;nn(n):1-12, Published April 11, 2021.

Methods: This is a clinical trial in which subjects with hyperlipidemia consumed about 1 or 2 ounces a day of almonds versus muffins with equivalent calories.

Results: “Almond-related energy bioaccessibility was 78.5%±3.1%, with an average energy loss of 21.2%±3.1% (40.6 kcal/d in the full-dose almond phase).”

Conclusion:  “Energy content of almonds may not be as bioaccessible in individuals with hyperlipidemia as predicted by Atwater factors, as suggested by the increased fat excretion with almond intake compared with the control.”

Comment #1: The authors went to a lot of expensive trouble to demonstrate what has been known for a long time: almonds as typically consumed have only about 80% of the calories listed in standard tables.  This is because some of the fat is excreted rather than absorbed.  Chewing is not as efficient as machine grinding in separating fat from fiber.  When nuts are machine ground, their fats are more fully released and their calories similar to values obtained in calorimeters.

So guess who paid for this?

Grant Support: …the Almond Board of California…[and several other sources].

Potential competing interests: Where to begin?  The list takes three full columns of printed page.  Several of the authors report grants or consulting arrangements with entities such as the Almond Board of California, American Peanut Council, International Nut & Dried Fruit Council (INC), International Tree Nut Council Research and Education Foundation, California Walnut Commission, Peanut Institute, and the International Tree Nut Council.  But authors also report funding relationships that seem irrelevant to this study, such as the Dairy Farmers of Canada, Ocean Spray, the Saskatchewan & Alberta Pulse Growers Associations, and Beyer Consumer Care.  Even odder are reports of an honorarium from the USDA for a lecture; travel support from the Canadian Society of Endocrinology and Metabolism to produce mini cases for the Canadian Diabetes Association (CDA); and, most unnecessarily, a book about vegetarian diets published by the daughters of one of the authors.

Comment #2:  I think disclosure statements like these are disrespectful of the disclosure requirement.  In this case, because several of the authors have so many financial relationships with food and drug companies, a listing of the nut-industry connections would have sufficed.  These alone would make it clear that these authors have conflicted interests that might deserve consideration in interpreting the study results.

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?