No Longer Poo-pooing Prunes!

March 31, 2012 6 min read

No Longer Poo-pooing Prunes!

No Longer Poo-pooing Prunes!

I was skeptical of the animal studies regarding increased bone density and prunes. The evidence regarding the bone benefits of prunes is mounting so, I am not longer poo-pooing prunes – I know I am supposed to say dried plums and at times in this article I manage to write the newer term, but honestly, they will always be prunes to me.

Dried plums are one of the world’s healthiest foods. It appears that they are packed with bone-building phenolic compounds, boron and potassium, all of which play important roles in bone health. Following is a human study that looked at bone markers and bone density exams.

Comparative effects of dried plum and dried apple on bone in postmenopausal women

Journal of Nutrition September 2011 - Hooshmand SChai SCSaadat RLPayton MEBrummel-Smith KArjmandi BH.

Breakdown of the study in a nutshell

  • 236 women were recruited who were 1-10 years postmenopausal. 160 women qualified and they were randomly assigned to: 100 grams/day dried plum (about 12) or dried apple.
  • Participants were not on hormone replacement or any other medication known to influence bone metabolism
  • Participants received 500 mg calcium plus 400 IU vitamin D daily
  • Bone mineral density (BMD) of lumbar spine, forearm, hip and whole body was assessed at baseline and at the end of the study using dual-energy X-ray absorptiometry.
  • Blood samples were collected at baseline, 3, 6 and 12 months to assess bone bio-markers.
  • Physical activity recall and 1-week FFQ were obtained at baseline, 3, 6 and 12 months to examine physical activity and dietary confounders as potential covariates

Findings

  • Dried plum significantly increased BMD of the ulna (forearm bone) and spine in comparison with dried apple.
  • Only dried plum significantly decreased serum levels of bone turnover markers including bone-specific alkaline phosphatase and tartrate-resistant acid phosphatase-5b.

Conclusion of authors

  • The findings of the present study confirmed the ability of dried plum in improving BMD in postmenopausal women in part due to suppressing the rate of bone turnover.

Opinion of authors

Among the nutritional factors, dried plum or prunes (Prunus domestica L.) is the most effective fruit in both preventing and reversing bone loss.

Dr. Lani’s comments:

While this is still a small study, it is another study showing that prunes may very well impact bone in a positive way in some individuals. I contacted the lead researcher, Dr. Hooshmand to discuss a few key points. One, dried plums cause many people gastrointestinal distress and loose stools. How well did participants maintain compliance? She said she started participants slowly until they reached 12 per day. The apple group was fine and did not need lead-in time. The other question I had about the study was what was the increase in bone density and was it statistically significant? I viewed the study data and from their posted findings, I do think there was a true increase in bone density in the distal ulna of about 4% on average and the lumbar spine about 2-3% on average. No change in the hip, which is expected. The first place bone density will show change is in the inner bone (cancellous bone) and the spine and distal ulna contains a high amount of cancellous bone. Bone markers (lab testing) also showed positive bone building findings in the prune group but not the apple group.

This study, along with many animal studies observing the effects of dried plums on bone, seems to be adding credibility to the conclusion that the shriveled up fruit benefits bone health.

What about sugar content? The following is from Diabeticcooking.com:

Some people with diabetes probably think they can’t have fruit, especially dried fruit like prunes, because of naturally occurring fruit sugars. However, prunes (also called dried plums) have a lot more going for them than their well-known laxative effect. Let’s take a fresh look at this underrated fruit, which humans have been eating since the days of the Roman Empire.

One serving of prunes, 1/4 cup, has just 100 calories, 26 grams of carbohydrate, and 3 grams of fiber. Prunes are fat-free, cholesterol-free, and low in sodium, and they have a low glycemic index, which means they are less likely to cause spikes in blood glucose when eaten alone. They also contain antioxidants, which research suggests may help prevent a number of chronic diseases.

Most people with diabetes should be able to fit fruit into their individualized eating plan. To enjoy fruit safely, make sure that your portion sizes are accurate. And if fruit raises your blood sugar during snack time, then opt for different foods at those times and work fruit into your eating plan at different times, or in combination with other foods. Prunes can be found in the dried fruits section of supermarkets. Choose soft fruits that have blue-black skins free from imperfection. They can be stored for up to six months in a cool, dry place if kept in an airtight container.

The obvious way to eat prunes is out of hand, but we have some other ideas. Chop them up and add them to your favorite green salad for a burst of sweet flavor, or stir them into a bowl of steaming Irish steel-cut oatmeal. Also consider using prune purée as a substitute for some or all of the fat in baked goods—this dramatically reduces fat and cholesterol.

Prune challenge – Please report back how prunes work or don’t work for you

Should you take prunes for your bones? They are a super food for your overall health and bone health too. The studies used 100 grams, which is equivalent to 10-12 medium sized prunes. For some, this dose of prunes can cause digestive problems, including loose stools. For those who suffer constipation it may work out very well, eliminating constipation. Start with 2-4 a day for a while and work your way up to 12 and report back on this blog what you discover. I was so excited after reading this study that I ate 6 prunes – bloat city! I am now happily eating 2 prunes twice daily and my plan is to add another prune every other day until I reach 12.

Will Dried Plums Reverse Osteoporosis? A Cautionary Note

Oh, if it were only that easy! The causes of osteoporosis is staggering including hormone imbalance, gastrointestinal problems resulting in poor digestion of nutrients, past history of an eating disorder, vitamin D deficiency and medications known to result in bone loss such as proton pump inhibitors (Nexium and Prilosec), SSRIs to name a few. A woman’s risk for accelerated bone loss increases significantly just before menopause and for three to ten years after menopause. If you have been diagnosed with osteoporosis or osteopenia make sure that your doctor has evaluated your case properly. How do you know whether or not your case has been diagnosed correctly? It is difficult for the layperson to know, however your doctor should specialize in osteoporosis and take a complete history, order lab work and keenly evaluate your diet and discuss the importance of digestive healthy.

Prune (Dried plum) update

My own prune experiment plus the response from many of my readers has resulted in some new thoughts and guidelines about bone healthy prunes. Prunes are mildly to moderately acid forming. Since many people run acidic which can also leach bone, it is important to balance prunes with alkaline foods. Here are some tips and thoughts about prunes (dried plums).

  • Put 12 or more prunes in a small Mason jar and cover them with boiling water. Let them cool to room temperature (30-60 minutes) and refrigerate. This will make the prunes soft and they will be easier to digest.
  • My article on prunes (hot link) noted a study that demonstrated an increase in bone density using 100 grams/day or about 12 medium sized prunes. A lot of people will not be able to tolerate so many prunes. For me 4-6 each day feels right as part of my bone healthy diet.
  • Prunes are OK for diabetics in small amounts as the fiber slows down the sugar from dumping into the system all at once. If you have a blood sugar problem try one or two and test your blood sugar to see if prunes are right for you.
  • Prunes are certain varieties of plums that have been allowed to fully ripen on the tree until they develop their maximum amount of sweetness. Then, once they are harvested, they are dried for up to 24 hours to remove most of the water.
  • When you buy whole prunes in the store, make sure they are moist which means they are fresh. If you buy in bulk, select prunes that are moist and flexible. Their skin should be a kind of bluish black with no blemishes.
  • Storing prunes – Store in airtight containers in a cool, dry place. In the refrigerator they'll last about nine months and can be frozen for about a year.

Prunes are indeed a bone healthy food as are many other foods.