by Marion Nestle

Currently browsing posts about: Fruits-and-vegetables

Dec 2 2019

Industry-funded scientific argument of the week: do blueberries prevent dementia?

I have posted several studies funded by blueberry trade associations over the years, including my all-time favorite, the one about prevention of erectile dysfunction.  Yes!

Can we please use some common sense here?  I love blueberries, grow and harvest them on my Manhattan terrace, and eat them whenever I can—but not because I think there is the remotest chance that they alone will keep me from dementia.

But scientists are seriously debating whether blueberries do or do not improve cognitive function in the elderly.

Study #1: Hein S, Whyte AR, Wood E, Rodriguez-Mateos A, Williams CM. Systematic review of the effects of blueberry on cognitive performance as we age. Journal of Gerontology: Series A. 2019;74(7):984-95

Conclusion: “Findings from these studies indicate that cognitive benefits may be found for delayed memory and executive function in children and for delayed memory, executive function, and psychomotor function in older healthy and MCI [mild cognitive impairment] adults”.

Funder: “This work was supported by an unrestricted grant from the Wild Blueberry Association of North America.”

The Debate:

Study #2:  The effect of blueberry interventions on cognitive performance and mood: A systematic review of randomized controlled trials.

Conclusion: “Based on the current evidence, blueberries may improve some measures of cognitive performance.”

Funding: The article, still in press, states that the authors declare no competing interests but provides no information about study funding.

The debate: 

My Comment: Of course blueberries are healthy and wouldn’t it be wonderful if all you had to do to prevent dementia was to eat some every day.  Skeptic that I am, I am happy to see widespread agreement that these studies do not constitute conclusive evidence.  Of course eating blueberries (or any other fruit) is healthy; eating fruits and vegetables is healthy.   This kind of research is about getting you to eat more blueberries, rather than any other kind of berry or fruit.

 

Mar 28 2019

Environmental Working Group: Pesticides in Produce

I am often asked about pesticides on fruits and vegetables, how serious a problem they are, and how to avoid them.  I don’t know how harmful they are; the research is too hard to do definitively.  But I generally favor the Precautionary Principle: while the science is pending, avoid them as much as you can.  Here’s how.

The Environmental Working Group has released its annual lists of the most and least pesticide-laden fruits and vegetables.

EWG’S DIRTY DOZEN FOR 2019

  1. Strawberries
  2. Spinach
  3. Kale
  4. Nectarines
  5. Apples
  6. Grapes
  7. Peaches
  8. Cherries
  9. Pears
  10. Tomatoes
  11. Celery
  12. Potatoes

The report emphasizes:

  • More than 90 percent of samples of strawberries, apples, cherries, spinach, nectarines, and kale tested positive for residues of two or more pesticides.
  • Multiple samples of kale showed 18 different pesticides.
  • Kale and spinach samples had, on average, 1.1 to 1.8 times as much pesticide residue by weight than any other crop.

EWG’S CLEAN FIFTEEN FOR 2019

  1. Avocados
  2. Sweet corn
  3. Pineapples
  4. Frozen sweet peas
  5. Onions
  6. Papayas
  7. Eggplants
  8. Asparagus
  9. Kiwis
  10. Cabbages
  11. Cauliflower
  12. Cantaloupes
  13. Broccoli
  14. Mushrooms
  15. Honeydew melons

See the full list of fruits and vegetables.This results may sound cute, but this report comes with impressive supporting material:

Mar 20 2019

Another Romaine lettuce outbreak takes its toll

I occasionally write about disease outbreaks caused by food and am especially interested in those caused by romaine lettuce, because it’s so hard to trace back where it came from and how it got contaminated.

This post is about two outbreaks of toxic E. coli O157:H7 from Romaine lettuce.

Outbreak #1: This one pretty much ended in November 2018.  My post on it is here.  The CDC’s page on it  is here.

It was especially serious:

  • 210 reported illnesses from 36 states
  • 96 hospitalizations
  • 27 cases of hemolytic uremic syndrome (HUS)
  • 5 deaths

Food safety lawyer Bill Marler posted a slide show analyzing this outbreak on his website: “Thanks to FOIA, the CDC and FDA, the 2018 E. coli Romaine Outbreak becoming more Transparent.”  At least that.

Outbreak #2.  In February, the FDA published its “Investigation Summary: Factors Potentially Contributing to the Contamination of Romaine Lettuce Implicated in the Fall 2018 Multi-State Outbreak of E. coli O157:H7.”

The FDA’s web page on this outbreak is here, and the CDC’s is here.

Bill Marler, whose firm represents victims of these outbreaks, posted annotated comments on the announcement.  He titled his post: “The FDA to Leafy Green Growers – “Please voluntarily stop poisoning your customers.”

Despite finding that E. coli outbreaks spanning years likely came from the same are or farm and was most likely caused by the same factors enumerated above, the FDA only sets forth “recommendations” that growers of leafy greens assess their growing operations for compliance with applicable requirements of the FSMA Produce Safety Rule and GAPs, including (see my snide comments in bold).

I will just give one example of his comments:

FDA continues to recommend (suggest, plead, beg, whine) that leafy green growers, buyer/shippers, and retailers be able to trace product back to the specific source in real time and make information about the source, such as harvest date and standardized growing regions, readily available for consumers on either packaging, point of sale signs, or by other means.

Voluntary, alas, isn’t good enough.  The FDA needs authority to require, demand, insist on.  Now.

If you want to see what this is about, take a look at the documents:

  • FDA’s final guidance for leafy green growers is here.
  • FDA guidance documents for leafy green growers are posted here. There are lots of them.
  • FDA guidance documents for retailers selling leafy greens are posted here.

 

 

Feb 25 2019

Industry-funded study of the week: avocados

I love avocados and think they—like all fruits and vegetables—are just fine to eat.

But avocado trade associations want us to eat more avocados.

A reporter sent me correspondence from an executive from a public relations firm that must represent some such trade association.  Over a period of about a month, the PR person sent the reporter four emails.  Here is message #4:

Subject: New avocado research just in time for American Heart Month

Sorry for the nudge – I just wanted to check in one more time to see if you’re working on any heart health related stories in which avocados could be a fit. If so, I thought your readers may find this research helpful. Either way, please let me know and I will stop bugging you 😊

The previous three messages extolled the heart-healthy benefits of eating avocados and offered to connect the reporter to a dietitian (identified by name) “for a phone or email interview to discuss this further and answer any questions.”

None of the messages stated who the PR firm or dietitian were working for.

But take a look at the research article.

The study’s conclusion: “Incorporating fresh Hass avocados in meals can help people achieve dietary recommendations to eat more fruits and vegetables and simple substitution strategies with avocados for carbohydrates can add to the nutrient diversity of the diet and potentially have important cardio-metabolic benefits worthy of investigating further.”

No surprise: “This research was supported by the Hass Avocado Board, Irvine, CA, USA.”  One of the authors “is a member of Avocado Nutrition Science Advisory.”

The reporter’s response to all this, and I quote: “AAAAHGGHGHGH.”

Mine too.

Dec 3 2018

Industry-funded study of the week: Cherries and exercise recovery in women

Since publication of my latest book, Unsavory Truth: How Food Companies Skew the Science of What We EatI’ve been collecting particularly delicious examples.

Here’s one I discovered through a tweet:

I looked up the press release.

Montmorency tart cherries may have the potential to improve exercise recovery in active females, suggests a new study published in the European Journal of Sport Science.

Researchers in the U.K. found that Montmorency tart cherry concentrate, when consumed twice a day for eight days, reduced self-reported muscle soreness and impacted certain aspects of muscle function after exercise, compared to a placebo.

Guess who funded this?Another example of a study with a sponsor predictable from its title, alas.

May 11 2018

Food for thought: top 20 fruits and vegetables

The Packer worries that millennials are not buying as much produce, even bananas, as older folks.

Maybe they will…?

Mar 19 2018

Another note on the Japanese food scene

While I was in Japan last week, a colleague from Washington State asked if his local apples were on sale in Japanese supermarkets.  I looked.  They were not.

If Washington State apples, organic or not, are exported to Japan, they are invisible in supermarkets.

They certainly are invisible to me.  Japanese food labels are in Japanese, as is information about country of origin.

But I asked.  The apples I saw were grown in Japan.

The only imported fruit I could find were bananas—not labeled as to origin but Japan does not grow them—and blueberries from Mexico.

Imported fruit, it seems, is not available for local consumption because it would compete with fruit produced by local farmers.

Less expensive fruit is imported but used for food service; it is not easily available for home purchase.

This helps explain why the Japanese do not eat much fruit.  It is expensive even in local stores.  The prices I saw looked like those in Manhattan.

And this brings me to the uniquely Japanese use of fruit as a luxury gift item.  These melons (not my photo) cost more than $100 each (the exchange rate is about ¥100 to a dollar).  But  saw melons like these in specialty stores costing much more—$150 and up.

As for strawberries, these gift packs cost $20 each but more elegant packages go much higher.

These are part of a complicated culture of obligatory gifts.  To Westerners like me, the prices are shocking.

The fruit is locally grown, at least.

Jan 18 2018

Durians: a market for durian-flavored products?

I was fascinated to read in FoodNavigator-Asia that the Chinese like durians so much that they have created a demand for durian-flavored food products.  Alibaba, the Amazon of China. offers plenty of durian products, but FoodNavigator mentions cookies, cakes, pie fillings, coffee, and much else.

Durians, shown below, are—to put it mildly—controversial.

People either love them or hate the way they smell and taste.

Singapore has banned them on subways.

Their, how shall I put this, unique odor comes from a variety of sulfur compounds.

For people who love them, they are worth eating for their nutritional benefits (like those of any other fruit).

Durian pizza, anyone?