My recent blog on the bone-building action of prunes drew a lot of attention and generated several interesting follow-up questions. Let me answer your questions as best I can.
Q. Wouldn’t eating 9-10 prunes a day cause diarrhea and/or gas?
A. As we well know, prunes have a laxative effect. The studies using 9-10 prunes a day, however, found that if people introduce the prunes slowly, taking a few to start and adding more over time, they do not experience excessively loose stools. Also, at the Center for Better Bones we find that soaking or lightly cooking the prunes also helps improve their digestibility, as does eating them warmed a bit, if necessary. Another tip is to spread your prunes out over at least 2 meals. Incidentally, prunes make a tasty dessert or sweet addition to hot cereal.
Q. Will eating all these prunes each day cause me to gain weight?
A. As it appears, consuming prunes did not cause weight gain and, in fact, prune researcher, Dr. Bahram Arjmandi specifically addresses this question, suggesting that prunes are so satisfying that they can actually aid in weight control. Also, recent work at the San Diego State University found snacking on prunes twice a day curbed the appetite while improving blood lipids, which actually aids weight management.
Q. I try to keep my blood sugar under control. Wouldn’t eating these prunes harm my blood sugar?
A. As Dr. Arjmandi reports, “Because prunes are low on the glycemic scale, they should not be a problem for people with diabetes.”
Q. Does drinking prune juice have the same effect as eating prunes?
A. All of the research I have found uses whole prunes, so I have to say that we simply do not know if prune juice would have the same bone-building impact.
Q. You list prunes as being an “acid-forming food.” So how can they help bones?
A. We have to remember that foods have many qualities, and not all acid-forming foods are bad for bones. In fact, protein is acid forming and yet adequate protein is essential for optimum bone health. Although prunes are slightly acid-forming, they contain phenolic and flavonoid plant compounds, which increase bone growth factors, so overall their impact on bone is very positive.
In April 2008 the U.S. National Osteoporosis Foundation published its new criteria for osteoporosis treatment, “Clinician’s Guide to Prevention and Treatment of Osteoporosis.” This handbook sets forth their official suggestions for treatment, which basically boil down to two sets of criteria for determining if a person should be given osteoporosis drugs. One criterion is based on bone density alone; the other concerns the assessment of fracture risk based on multiple risk factors other than bone density.
The guidelines were designed to help doctors determine who to treat and were well intended, but I can’t help but ask, “What do they mean?” What do these new NOF guidelines mean for women (the majority of osteoporosis patients), and just how many women would be treated with osteoporosis drugs if these guidelines were followed by doctors around the country?
Interestingly enough these same questions were asked by researchers from the noted U.S. Study of Osteoporotic Fractures. The answer they came up with is quite astounding. Applying these new criteria to women in the large, representative Study of Osteoporotic Fractures these researchers calculate that at least 72% of white women aged 65 and older, and 93% of women aged 75 and over, would be told to take osteoporosis drugs.
To me this is startling and rather frightening. First, as reported by the U.S. Surgeon General, only 17% of white women aged 50 older will experience a hip fracture in their life; 15% a vertebral fracture, and 16% a forearm fracture. Second, the side effects of these drugs are well noted and substantial — and they would be recommend to the vast majority of older Caucasian women. Third, I am perplexed at such a strong focus on drug therapy these days when science is now documenting the many life-supporting ways we can both prevent osteoporotic fracture and at the same time build better overall health. For example, many researchers, myself included, estimate that nearly half of all osteoporotic fractures could be prevented with adequate vitamin D supplementation with even greater results possible if all the key 20 bone-building nutrients were consumed in adequate amounts.
If you are interested in avoiding the risks of osteoporosis drug therapy, know that there are science-based, natural alternatives, and I am happy to share these with you. You can start by assessing your fracture risk through our simple fracture risk and bone health profile.
Wishing you all Better Bones and a Better Body.
Donaldson, MG et al. Estimates of the proportion of older white women who would be recommended for pharmacological treatment by the new U. S. National Osteoporosis Foundation Guidelines. J Bone Mineral Res 2009; 24 (4): 675-674.
U.S. Surgeon General. Bone Health and Osteoporosis: A Report of the Surgeon General. U.S. Dept of Health and Human Services, Rockville, MD, 2004.
My friend and fellow osteoporosis researcher Dr. Bahram Arjmandi says yes, the humble prune can reverse bone loss, and his research data is looking strong. For more than a decade Dr. Arjmandi of Florida State University in Tallahassee has tested a wide variety of “functional foods” for their potential impact on bone health. He has studied soy, blueberries, strawberries, raisins, dates, and finally prunes. No other natural substance, he reports, comes near to having the bone-building effect of prunes. Further, when I saw him at the ASBMR international bone meeting last fall, he reported he had never seen any natural substance produce such consistent beneficial bone-building results.
Dr. Arjmandi’s several successful animal and human studies document that special phenolic compounds in dried plums up-regulate growth factors linked to bone formation (such as IGF-1) and counter the activity of factors that inhibit bone formation (such as TNF-alpha). It probably also helps that prunes are one of the foods highest in antioxidants and also contain generous amounts of various key bone nutrients including potassium, boron, and copper. While Dr. Arjmandi has found other natural substances capable of halting bone loss, prunes were the only food found to actually restore lost bone.
This summer Dr. Arjmandi and colleagues will complete a landmark, controlled human clinical trial on prunes and bone health. For this study, 120 post-menopausal women have been taking either 100 grams of prunes (9-10 a day) or an equivalent portion of dried apples for one year. While it will be a few more months before all the research data is in, thus far 30 women in the prune group have had at least a 6% increase in hip bone, and one woman had an exceptional 11% increase consuming prunes over the year. Preliminary data from a segment of research subjects found that all prune-eaters showed at least some improvement in bone mass by six months into the study. [update on this study can be found here]
For several years I have heard Dr. Arjmandi speak of his prune research and read many of his research articles. It makes sense: if you could limit factors that hinder bone formation, such as inflammation and oxidative stress, and at the same time up-regulate new bone formation growth factors, and provide key bone nutrients, you could well accomplish the unthinkable and stimulate new bone formation with a simple, wholesome food substance.
At the Center for Better Bones, a group of us (including myself) are doing our own “prune experiment.” If you are inclined to join us, take Dr. Arjmandi’s advice and start slowly with a few prunes a day, working up to the full 9-10 over time. I have found soaked or stewed prunes are easier to digest, and Dr. Arjmandi has found that prunes do not lead to either weight gain or increased blood sugar levels. Also they should help build new bone in men as well as women.
Arjmandi, BH et al. 2002. Dried plums improve indices of bone formation in postmenopausal women. Journal of Women’s Health & Gender-Based Medicine, 11:61-68.
Hooshmand, S and Arjmandi, BH. 2009. Viewpoint: Dried plum, an emerging functional food that may effectively improve bone health. Ageing Res Rev, Apr 8:122-7.