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.