What Ten Dried Plums (Prunes) a Day Can Do for Your Bones - The Florida State University Study - Understanding the Science Behind the Prune's Effect Upon Bone Health

 

 

 

 “Over my career, I have tested numerous fruits, including figs, dates, strawberries and raisins, and none of them come anywhere close to having the effect on bone density that dried plums, or prunes, have.  All fruits and vegetables have a positive effect on nutrition, but in terms of bone health, this particular food is exceptional.

Dried plum(s) significantly increased bone mineral density of the ulna & spine in comparison with dried apples.

In comparison with corresponding baseline values, only dried plum(s) significantly decreased serum levels of bone turnover markers, including bone-specific alkaline phosphatase and tartrate-resistant acid phosphatase-5b. 

The findings of this present study confirm the ability of dried plums(s) in improving bone mineral density in postmenopausal women in part due to suppressing the rate of of bone turnover and bone resorption."

 

-Bahram H. Arjmandi, Florida State’s Margaret A. Sitton Professor and chairman of the Department of Nutrition, Food and Exercise Sciences in the College of Human Sciences.  

Hooshmand, S et al   "Comparative effects of dried plum and dried apple on bone in postmenopausal women,"  British Journal of Nutrition 106(6):923-30, September, 2011.   Epub 2011 May 31.

 

 

First it was calcium.  Then it was weight-bearing exercise.  Then it was vitamin D.  And yes,  it's still all of these (though less calcium lately)--but now there's a new kid on the bone mineral density block.   

Now, consider the dried plum (formerly known as "the prune") for a boost in your bone health!

Yes, there's always that "back-up plan" of drug options--the bisphosphonates & raloxifene, if all else fails. 

But, now there's a serious suggestion by the FDA of a five-year limit on drug therapy--or at least taking a recommended "drug holiday".   Stay tuned for revised drug labeling in November 2011.  Read more here.

According to the FDA, between 5.1 million and 5.7 million patients in the United States have received prescriptions for the drugs for each of the years 2005 through 2009.

Earlier this month (September 2011) an FDA staff report said there was no advantage of taking the popular bone drugs of Boniva, Actonel, and Fosamax for more than five years. 

 

“These results suggest no significant advantage of continuing drug therapy beyond 5 years,” according to agency’s 45-page review of scientific evidence.

As for side effects, the report said, there is no solid evidence the drugs, called bisphosphonates, cause unusual breaks of the femur bone, a jaw injury called osteonecrosis, or esophageal cancer. At the same time, the agency said, those rare but dangerous outcomes cannot be ruled out because it has been so difficult to study them for various reasons.

“The safety of long-term bisphosphonate therapy continues to be unclear as study results are conflicting,” according to the F.D.A. report.    Duff Wilson, "FDA Staff:  5 Years May Be Enough for Bone Drugs,"   New York Times, September 7, 2011.

 

If you received this post via email, click here to get to the web version with all the links & a video.

 

Meet the Dried Plum! 

Looks like perfect timing to consider adding prunes to your diet and take a careful look at Hooshmand's & Arjmandi's new research.

I couldn't wait to look at this study--and I admit that I'm a rank amateur--but, I'm impressed with the results of their well-designed study.  These researchers have been analyzing the effects of dried plums on bone strength for years in their lab--first in animals, and then in humans. 

In 2002 they even ran a short-term 3 month prune study on women, which had positive outcomes.  (click here)  And they've also pored over years of published research by other scientists on the effects of nutrients & prunes on bones.

Best of all--they provide detailed explanations of how it is possible for the lowly prune to physiologically make bones stronger.  Now even I get it!

 

The Florida State & Oklahoma State University Postmenopausal Bone Study Explained - Dried Plums Face-off Against Dried Apples

 

Who was in this study?

 

100 postmenopausal women completed the study over a period of 12 months.  No one was on bone medications, anabolic agents, steroids, or any drugs that can alter bone or calcium metabolism. Women with metabolic bone disease, other chronic diseases, or heavy smokers were excluded.   Anyone who regularly ate prunes or prune juice could not participate.  No one had a BMD t-score at any site below 2.5 sd of the mean.

 

What did the participants have to eat?

 

Fifty-five women were in a treatment group (and completed the study) that was assigned to consume 100 grams of prunes a day--that's about 10 prunes--for 12 months.  "Because of the known laxative properties of dried plums, the participants were asked to gradually incorporate the plums into their diet."  

 

Note:  One HHLL reader took an early test-drive of the prune regimen, but made the mistake of eating 10 prunes all at once--and suffered the consequences.  Her physician recently told her to go off of Fosamax--since she'd been on it for over 5 years.  She was highly motivated to keep her bones strong, and eating prunes seemed like a good plan, so, after her initial "faux pas" she figured out an easy way to consume the 10 prunes--just space them out--eating about one an hour works well for her, and she loves the taste!

 

Forty-five women were in a second treatment group (and completed the study) that was assigned to consume 75 grams of dried apples--which have an equivalent amount of calories, carbohydrates, fat, and fiber--as the dried plums.

Both groups also took 500 mg of calcium, plus 400 IUs of vitamin D.

Compliance was high--at 82%--the same for the apple & dried plum groups.  The women liked the prunes. 

 

How was the study designed?  What did the researchers measure?

 

Physical measurements: At the study's start everyone had medical, nutritional, & physical activity histories taken.   Height & weight was measued at the start, and at 3, 6, and 12 months.

BMD measurements:  Bone density was measured at the start--and at the end of the treatment with dual-energy x-ray absorptiometry--and the whole-body, lumbar spine, hip & forearm BMD's were all measured.

Bone marker measurements:  Blood samples to measure biomarkers of bone turnover were taken from everyone at the start, and at 3, 6, and 12 months.   Here's what the researchers looked at: 

• The markers of bone turnover:  bone-specific alkaline phosphatase (BALP), osteocalcin (OC)
• The markers of bone resorption:  tartarate-resistant acid phosphatase-5b (TRAP5b)
• The marker of inflammation: C-reactive protein (CRP) was taken to determine the potential anti-inflammatory role of dried plums in modulating bone metabolism

 

Who won?  The Apples or the Plums?  And, the envelope, please!!

• Both fruits were palatable, and the "dosage" was easy to adhere to.
• Both groups were still eating the same amount of food at the start of the study, as they were throughout the study, yet, remarkably, no one gained weight, in spite of the additional calories.
• Both dried fruit groups experienced bone-protective effects based on the positive changes from baseline in the ulna, spine, femoral neck, total hip, and whole-body BMD.
• The dried prune group had more significant increases in the BMD of the ulna & spine--compared to the dried apple group.
• The dried plum group had a significant reduction in the markers of bone turnover (a good thing!), compared to the dried apple group.  The reduction in these markers helps to explain how dried plums improve the BMD of post-menopausal women, in part, due to slowing down the rate of bone turnover.
• The dried plum group had a significant decrease in the marker of bone resorption (a good thing!) at 3 months and it remained the same through the end of the study.  The dried apple group didn't change much over the course of the study--but it increased at the 12 month mark (not a good thing!)
• The inflammation marker (CRP) decreased (a good thing!) in the plum group after 3 months--and remained the same until the end of the study.  In the apple group, the CRP was the same after 3 months, and decreased thereafter--ending up insignificantly higher than the plum group. 

 

What Ten Prunes a Day Can Do for Your Bones and the Reasons Why It Works

 

• Bone density increased.  Ten dried plums a day (100 grams) eaten daily for 12 months showed increases over baseline in the bone mineral density of the ulna, spine, femoral neck, total hip, and whole-body.   Both the prune & dried apple groups showed similar bone density improvements in the neck of the femur and the total hip.
• Ulna & spine.  The dried plum group showed significant increases of the ulna (long bone of the forearm) & spine compared to the dried apple group.  According to the authors, "These findings suggest that dried plum is particularly effective in reducing the risk of fracture in the ulna & spine as indicated by the higher BMD in these sites."
• No bone loss.  None of the women in the study lost any bone--whether they were eating dried apples or prunes.
• The earlier animal studies.  Earlier animal studies strongly suggest that dried plums have a potent effect on preventing & reversing bone loss as "evident by the higher bone densities, [higher] mineral contents, [increased] percentage of the trabecular bone area (this is the all-important lattice-like network of struts that supports our bones & women can lose up to 50% of this type of bone-read more here), and the tendency to reduce marrow space in the long bones in rats."
• Bone biomarker improvements.  Bone mineral density biomarkers found in the blood also showed improvement after 12 months.  According to Arjmandi, this is due in part to the ability of dried plums to suppress the rate of bone resorption, or the breakdown of bone, which tends to exceed the rate of new bone growth as people age.
• No weight gain.  Although the women consumed about 200 calories worth of prunes a day, neither their weight nor BMI increased--perhaps due to the increased fiber content of the prunes--about 6-7.1 grams of fiber.
• The vitamin C, K, boron, & phytochemical connection to bone health.   Prunes are high in the antioxidant compounds of neochlorogenic and chlorogenic acids (click here) that scavenge potentially damaging free radicals. Previous studies have shown this action helps to prevent bone loss. Click here & here.  Prunes have higher amounts of boron than most fruits--and "boron modulates bone and calcium metabolism, and plays an important role in preserving BMD."  Click here.  And prunes have high amounts of vitamin K which influences bone health by improving calcium balance & promoting normal bone mineralization.
• Dried plums may improve bone mass by slowing down the rate of bone turnover.  The authors speculate that dried plums may improve bone health by suppressing  the rate of bone resorption more so than the rate of bone formation.  However, this can only be shown through bone biopsies.
• Dried plums reduce inflammation--perhaps another reason why they improve bone.  The dried plums in this study significantly reduced the C-Reactive Protein (CRP) levels (a measure of inflammation) after 3 months--and this improved level was maintained, thereafter.  A high CRP is linked to a number of chronic diseases, including osteoporosis.  Click here.

Full Disclosure & Author Acknowledgements:  This study was supported by the National Research Initiative of the USDA Cooperative State Research, Education & Extension Services, grant #2005-35200-17053.  The California Dried Plum Board provided the dried plums, & Bayer Healthcare supplied the calcium & vitamin D supplements.  There are no conflicts of interest.

 

Nutritional Data for a Ten-Prune Serving

Nutrition Facts Prunes
Serving Size: 10 prunes
Amount Per Serving
Calories	200
Total Fat	0.3g
Saturated Fat	0.1g
Trans Fat	0g
Cholesterol	0mg
Sodium	2mg
Carbohydrate	53.7g
Dietary Fiber	6g
Sugars	32g
Protein	1.8g
Vitamin A 13% Vitamin C 1% Calcium    4% Iron 4%

Potassium:  732 mg

Boron:  3 mg

Magnesium:  41 mg

Vitamin K:  59.5 mdg

 

Dr. Bahram H. Arjmandi and a Study Participant Discuss the Study (1:46 minutes)

Please click here if you don't see the video.

 

 

Want Even More Evidence of the Benefits of Dried Plums?  

 

First off--just take a look at Dr. Arjmandi's extensive bibliography!

These highlights come for Pamela Durkin, a registered nutritional consultant and freelance journalist living in Victoria, Australia.  Source: Alive Magazine  #342, April 2011   A HHLL sent it to me.

• Prunes are a natural laxative because they're high in insoluble fiber, which helps them to absorb water.  They also contain "a compound called dihydroxyphenyl isatin, which stimulates the intestine, causing it to contract."   Good reason NOT TO EAT 10 prunes at one time!!!
• Prunes also contain soluble fiber which helps to lower cholesterol.
• It's loaded with potassium which helps to lower blood pressure.
• It contain phenolic compounds (neochlorogenic and chlorogenic acids) that help to inhibit the oxidation of LDL cholesterol.
• It's high in boron which helps to regulate mineral metabolism, optimize estrogen levels, & increase calcium absorption.
• Boron helps to convert vitamin D to its active form, which helps the osteoblasts utilize calcium for bone formation.
• Prunes are loaded with disease-fighting carotenoids like beta-carotene, lutein, & zeaxanthin, as well as anthocyanins, proanthocyanins, and phenols.  No surprise that they have a higher ORAC (measure of antioxidant activity) than blueberries---clocking in at 8,059 for a 100 gram serving--which is exactly the 10 prunes that Dr. Arjmandi is recommending.  The blueberry measures in at 4,669.

Learn more from Pamela Durkin by following the link to her article.

 

It's not often we see such a provocative study about a functional food.  I've never considered eating prunes before reading this study--but I'm definitely going to give them a try!  Full disclosure:  I haven't started yet.

HHLL reader "Teacher Fan" gives them a big thumbs up.   Just take her advice--space them out over the day.  She now keeps a bag in her purse to munch on throughout the school day.

 

For more on the ongoing controversies about bone health, osteopenia, and prescription bone meds, see below:

What's the Best Way to Treat Osteopenia? Diet, Vitamin D, Calcium, Drugs Like Bisphosphonates, or Weight Training? Check Your Fracture Risk with the W.H.O. FRAX Tool to Help You Decide

 

NPR's Award-winning broadcast:  How A Bone Disease Grew To Fit The Prescription, (a must read!) by Alix Spiegel 

 

Reconsidering Calcium Supplements - What the Experts Say about Bone Health, Calcium Requirements, Dairy, and Strength Training

 

And, HOT OFF THE PRESS, from HHLL reader, Tom.  Wall Street Journal, September 20, 2011, "Yes, You Are Getting Shorter,"  by Melinda Beck   One more good reason to add dried plums to the menu!

 

 OK, HHLL readers, please weigh in with your opinions!  Does this sound too good to be true---or worth a try?

 

Comments

[Betsy]

I've been on this prune treatment for about a year, thanks to Dr. Susan Brown's (Better Bones site) early reporting of Arjmandi's work. But I have a couple of questions about the study and thought I might as well ask them here. Since the prunes "suppress the rate of bone resorption", how is this action different from that of bisphosphonates? Won't this mean that prune-eaters will just have more old brittle bone?

This last is only partly tongue-in-cheek: why no speculation and looking askance at the study because the prune assn supplied prunes for it (like supplying funding, right?)? Couldn't we say this is similar to the dairy board funding a study that found dairy was a good thing to include in your diet?

[The Healthy Librarian]

Betsy,

Gee, good questions, that I'm not qualified to answer.
I think that Dr. A. takes a shot at answering your question-see below. Bottom line--you'd have to do bone biopsies to see what's going on in the inside of the bone.

My "amateur" answer to your excellent question about whether or not the anti-resorptive effects of prunes might cause "brittle bones"--would be that it's a natural food--and likely has a more modulated effect than a drug--and in no way prohibits the natural bone formation. Plus, it has added benefits that the drugs don't: antioxidant properties, boron, vitamin K, etc.

Here's exactly what the article says--sure to put you all to sleep--that may address your question about the "brittle bone" issue:

In an animal study: "More importantly. dried plum reversed the loss of travecular architectural properties such as trabecular number, connectivity density & trabecular separation, which to our knowledge is unique to dried plums in comparison with soya or its isoflavones, flaxseed, apples, blueberries & strawberries..

According to Lane et al, once trabecular bone is lost, it would be difficult to restore it.

The efficacy of dried plum in the reversal of bone loss in rat models of established osteoporosis exceeds many of the agents with bone-forming ability.."

But, in humans, this is still an unknown--because it would require a bone biopsy to determine.

Re taking the plums from the Dried Prune Board--that's for individuals to decide on whether that's a conflict of interest---it wasn't big $$ for salaries, labs, or equipment or DEXA scans. It was just prunes.

[Carynalison]

Well, I don't really need more excuses to load up on prunes! :-) And glad to find out about contraction issue, will try to spread them out throughout the day.

I have a sort of unrelated question just in case you know ... I live in CA but my mom lives in Cleveland. My sibs and I want to hook her up with a plant-strong personal chef for a week or so to help kickstart her plantstrong diet -- is there such a person in Cleveland? It seems like a great business to be in -- a few weeks of kickstart the diet, super-charge and clear the pantry, stock the fridge ...

Love your blog! We took the plunge last February and are loving it. You have made a great difference to our little family.

[The Healthy Librarian]

Carynalison,

There used to be: Amy Cramer--but she recently moved to Boulder, CO. Does anyone have a suggestion for a personal plant-strong chef in NE Ohio? There has to be someone in the area! I'll ask around.

[Jo M]

Dannon yogurt used to have a "prune whip" flavor. You can make the same thing by soaking prunes in water for a few hours, then pureeing them in the blender, and mixing into soy yogurt, perhaps with a dash of spice.

Soaked and pureed prunes can also be used like applesauce in place of oil in baked goods. But consider flavor compatibility - good for gingerbread or buckwheat pancakes, probably not so good for cornbread.

[Ruth]

Thanks for a great article. I'm forwarding it to me 3 sisters, daughter and daughter-in-law. As a dental hygenist, I'm very aware of some of the bad side affects of these drugs (loss of the jaw bones) and have warned my family to do everything to avoid needing these drugs. Plus, for some of us it's a two-fer as prunes can solve an issue we tend to get when we travel.

[Carole B]

First, thanks for this blog! It's amazing and so gracious of you to share with the world.

Does it matter if the prunes are sulfured or not? How about cooking them? The sulfured ones are so soft and juicy; I buy those for eating out of the bag. The unsulfured ones are stewed in my house because they are so hard and dry. Does it matter which you eat or the method of preparation? (I'll assume the traditional Passover soaked-in-kosher-wine is not the way we're going to go here! ;-) )

[Carol]

Do you suppose that prune juice would also be helpful? I LOVE me my prune juice, including heated up during the winter months ...

[Fat Fudge]

Thank you for printing this! My Mom is currently taking Boniva and wants to stop because of the pains in her legs and knees. Unfortunately, her Doctor believes that she should continue with it. I don't know if my Mom will want to try prunes, though. She already says that she has too much of a gas problem! I am going to try it not only because I have osteopenia, but I love prunes.

[Willow]

Oh yay! I just finished dehydrating several pounds of plums, so I have my year's supply ready for consumption.

[Bonnie]

It sounds both too good to be true and too easy not to try. The science is convincing and I will be adding prunes to my diet as a healthy snack based on this article. I really appreciate the information.

[The Healthy Librarian]

Bonnie,

So well said: Too good to be true--too easy not to try!

Carole B.: No mention of sulphured or unsulphered in the article.

[The Healthy Librarian]

Carol: Study was done with whole fruit, not the juice. Stick with prunes.

[Pamela Wildermuth]

Hello to you again,
I am on Holidays with our Daughter and Family in Atlanta GA. I am enjoying going to Whole Foods and Trader Joes finding a lot of the foods that you have written about over the last 15 months that I have been following your emails. It is 15 months that I have been eating plant-based, with a few 'hiccups' along the way, and my last Blood tests showed numbers were down so very pleasing. I would have liked to have been able to have got an appointment to see Dr Esselstyn, but just didn't work out. I will get his DVD and Forks over Knives DVD and book [ have to go into Apple to see if they will play on my Mac] as they are not compatable with our system in Australia.
Keep up the fantastic effort of sending out your emails, they have been a great help and support to me and am sure a lot of people everywhere.
Thanks,
Pamela Wildermuth, Australia

[The Healthy Librarian]

A warm welcome to the US, Pamela! Hope you're enjoying your visit to Atlanta & spending time with your family--and FINALLY, getting to stock up on everything at Trader Joe's & Whole Foods. So glad that Dr. E has that DVD now available of his day-long session. No need for that extra side trip.

Great news about all your health successes--and thank you so so very much for all your kind words, and support! Flattery will get your everywhere. Hope your Mac will play the DVD's!

[Kate H]

Great news since I love prunes and have bone loss. However, doesn't Dr. Esselstyn recommend that we limit our fruit intake to 3 a day? Just want to know what you think. I think I will eat my prunes.

[Carol]

Thanks for another provocative posting....

A few questions occur to me: One, why prunes and not fresh plums? I like those much better! And two, if we did eat 10 plums a day, we'd be way over the 3 fruit limit....so aren't we still over, even though the water has been removed? And three, 32 grams of extra sugar seems like something we're trying to avoid......It's all so complicated! Should we just lift more weights instead? ; )

Also a P.S. - Not intended to rush you, but will we still be seeing part 2 of the 15-mo experiment one of these days, or has it slipped by me? I'm looking forward to hearing your thoughts on essential tools, etc.

Thanks again for all the great work you do on our behalf.

[Mitzi]

Definitely worth a shot. My grandmother lost several inches of height to osteoporosis, and I already eat raisins every morning in my oatmeal, so subbing prunes and eating them at snack times would be fine. I would expect a more moderate effect than with drugs, so brittle bones would be less of a concern. With whole foods, you get a package your body is designed/adapted to process. With drugs, not so much.

[Betty Amer]

I'm intrigued by the fact that the participants didn't gain weight. Did the prunes displace other foods, or were they really in addition to usual intake?

[The Healthy Librarian]

Kate: Yes,Dr. E. does advise limits on fruit, especially on dried fruits for folks who have high triglycerides.

That said--the 10 prunes in this study are spaced out over a day--tiny amounts of sugar--like 2.4 grams of sugar per prune. The amount of sugar in 10 prunes (100 grams) is 32 grams--about what's in 2 apples.

So, yes, there's a conflict here--but, I know I probably snack on more than 3 servings of fruit a day, as it is.

If you were to give it a try--keep on eye on your triglycerides to see if they're affected.

[Leslie]

Yay! Good post - I've been missing these types of posts. Also, I LOVE Dried Plums/Prunes. I got into eating them when living in the middle east. Thanks for the good news.
DIL Leslie

[The Healthy Librarian]

Kate H: You're right about Esselstyn's 3 fruit recommendation. The sugar in 10 prunes is equivalent to 2 apples--wonder if its different if it's spaced out into tiny sugar hits throughout the day--if the effect upon triglycerides is marginal. Anyone know?

Betty: Hi Betty,

I was intrigued, too, about the calories. I would have thought the women would just eat less. But at baseline (they were reported in kJ units, so I converted them) the daily intake was 1644 calories, and at 12 months it was 1846 calories--basically the calories in 10 prunes. So it looked liked the prunes did not displace other calories at all. That's why the authors were surprised that the weight stayed the same over the year. They speculate that it was the fiber in the prunes. Any thoughts?

[Betsy]

RE: sugars and triglycerides. Doesn't it make a difference that the sugars in prunes are accompanied by all that fiber?

And just wanted to add that I've been weighing my daily prune allotment and 100 grams = 3.5 oz. A pound of prunes doesn't last long at that rate of consumption.

(Thanks for your response to my earlier questions about the study!)

[hannahmarie]

Thanks for this post! I have some prunes sitting in my cupboard that I haven't been doing a good job of eating but this gives me motivation to dig back in!

[Lindy]

Osteoporosis runs in my family. I went out immediately after reading this and bought a packet of organic prunes. "Why not?", I thought. Delicious with oat porridge, and so much nicer than taking a pill.

[CB]

It could be that any consistent amount of prunes would be advantageous. I think I'd tire of ten a day, but ten a week is feasible for me.

[Janet]

What do you think of this blog post on prunes....?

http://thehealingkitchen.blogspot.com/2011/09/plums-and-prunes.html

[The Healthy Librarian]

Janet,

Good post--and yes, it's true--there are many varieties of plums & it's easy to see the differences between them in the grocery store. Prunes do come from those tiny Italian "prune" plums, that are usually available in the late summer or fall. You can eat a bunch of them at a time--and they're my husband's favorite.