Flashback Friday: Prunes for Osteoporosis

We are in an epidemic of osteoporosis. Ten million Americans have it, and one in three older women will get it. We urgently need public health strategies to maintain bone health, and prevent osteoporosis. Might fruits and vegetables be the unexpected natural answer to the question of osteoporosis prevention?

Evidence from a variety of studies strongly points to a positive link between fruit and vegetable consumption, and indexes of bone health, such as bone mineral density. And, the size of the effect in the older women is impressive: doubling the fruit intake is associated with a 5% higher spine mineralization. And, the same relationship with young women, too. And, eating lots of fruit in childhood may protect bones throughout life—something that was not found for milk intake, as I’ve explored before.

Bone health isn’t just about calcium; there are several key nutrients in vegetables, fruits, and beans associated with better bone mineral density. But, does that translate into lower hip fracture risk? The Singapore Chinese Health Study found that a diet rich in plant-based foods, namely vegetables, fruits, and beans, such as soy, may indeed reduce the risk of hip fracture—but why?

The underlying mechanism in postmenopausal osteoporosis is an imbalance between bone cessation and bone formation, and oxidative stress may play a role in this balance. There are two types of bone cells: the bone-forming osteoblasts, and the bone-dismantling osteoclasts. Osteoblasts are continually laying down new bone, while osteoclasts chisel away old bone—and they use free radicals as the molecular chisel to chip away our bone.

Too many free radicals in our system, though, may lead to excessive bone breakdown. Antioxidant defenses appear markedly decreased in osteoporotic women. Elderly osteoporotic women were found to have consistently lower levels of all natural antioxidants tested. Because excessive free radicals may contribute to bone loss, it’s important to elucidate the potential role antioxidant-rich fruits play in mitigating the bone loss that leads to the development of osteoporosis. The thought is that fruits upregulate the bone building cells, and downregulate the bone-eating cells, tipping the balance towards greater bone mass.

So, let’s put a fruit to the test. Which one are we going to pick? Dried plums were chosen, because they have among the highest antioxidant ranking among commonly consumed fruits and vegetables—and because the researchers scored a grant from the California Dried Plum Board.

When you think of prunes, you think of bowels, not bones. But over a decade ago, researchers at Oklahoma State tried giving a dozen prunes a day to a group of postmenopausal women, using a dozen dried apple rings as a control. After three months, only the subjects who consumed the prunes had significant elevations in an enzyme marker of bone formation, although prunes didn’t seem to affect markers of bone breakdown. So, prunes may help more with building bones than preventing bone loss. Though, the reverse was found with almonds; so, maybe a little prune-almond trail mix is in order.

With this bump in bone formation indices, one might expect, with this improvement, that if they did a longer study, one would actually see an impact on bone mineral density. And nine years later, just such a study was done. Twelve months on dried plums versus apples, and both dried fruit regimens appeared to have bone-protective effects—though the prunes seemed to work better in the arm bone and spine.

So, the dried plum marketing board wants everyone to know that dried plums are “the most effective fruit in both preventing and reversing bone loss.” But only two fruits have ever been tested—plums and apples.

But if this does pan out for other plants, a “fruit and vegetables” approach may provide a very sensible (and natural) alternative therapy for osteoporosis treatment, one that is likely to have numerous additional health-related benefits. All we have to do is convince people to actually do it.

To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Katie Schloer.

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• C L Shen, V von Bergen, M C Chyu, M R Jenkins, H Mo, C H Chen, I S Kwun. Fruits and dietary phytochemicals in bone protection. Nutr Res. 2012 Dec;32(12):897-910.
• Z Dai, L M Butler, R M van Dam, L W Ang, J M Yuan, W P Koh. Adherence to a vegetable-fruit-soy dietary pattern or the Alternative Healthy Eating Index is associated with lower hip fracture risk among Singapore Chinese. J Nutr. 2014 Apr;144(4):511-8.
• A N Sontakke, R S Tare. A duality in the roles of reactive oxygen species with respect to bone metabolism. Clin Chim Acta. 2002 Apr;318(1-2):145-8.
• C Cervellati, G Bonaccorsi, E Cremonini, A Romani, E Fila, M C Castaldini, S Ferrazzini, M Giganti, L Massari. Oxidative stress and bone resorption interplay as a possible trigger for postmenopausal osteoporosis. Biomed Res Int. 2014;2014:569563.
• S A New, S P Robins, M K Campbell, J C Martin, M J Garton, C Bolton-Smith, D A Grubb, S J Lee, D M Reid. Dietary influences on bone mass and bone metabolism: further evidence of a positive link between fruit and vegetable consumption and bone health? Am J Clin Nutr. 2000 Jan;71(1):142-51.
• S A Lanham-New. Fruit and vegetables: the unexpected natural answer to the question of osteoporosis prevention? Am J Clin Nutr. 2006 Jun;83(6):1254-5.
• C J Prynne, G D Mishra, M A O'Connell, G Muniz, M A Laskey, L Yan, A Prentice, F Ginty. Fruit and vegetable intakes and bone mineral status: a cross sectional study in 5 age and sex cohorts. Am J Clin Nutr. 2006 Jun;83(6):1420-8.
• D Maggio, M Barabani, M Pierandrei, M C Polidori, M Catani, P Mecocci, U Senin, R Pacifici, A Cherubini. Marked decrease in plasma antioxidants in aged osteoporotic women: results of a cross-sectional study. J Clin Endocrinol Metab. 2003 Apr;88(4):1523-7.
• O Altindag, O Erel, N Soran, H Celik, S Selek. Total oxidative/anti-oxidative status and relation to bone mineral density in osteoporosis. Rheumatol Int. 2008 Feb;28(4):317-21.
• M Stacewicz-Sapuntzakis, P E Bowen, E A Hussain, B I Damayanti-Wood, N R Farnsworth. Chemical composition and potential health effects of prunes: a functional food? Crit Rev Food Sci Nutr. 2001 May;41(4):251-86.
• B H Arjmandi, D A Khalil, E A Lucas, A Georgis, B J Stoecker, C Hardin, M E Payton, R A Wild. Dried plums improve indices of bone formation in postmenopausal women. J Womens Health Gend Based Med. 2002 Jan-Feb;11(1):61-8.
• S Hooshmand, B H Arjmandi. Viewpoint: dried plum, an emerging functional food that may effectively improve bone health. Ageing Res Rev. 2009 Apr;8(2):122-7.
• S Hooshmand, S C Chai, R L Saadat, M E Payton, K Brummel-Smith, B H Arjmandi. Comparative effects of dried plum and dried apple on bone in postmenopausal women. Br J Nutr. 2011 Sep;106(6):923-30.
• M Stacewicz-Sapuntzakis. Dried plums and their products: composition and health effects--an updated review. Crit Rev Food Sci Nutr. 2013;53(12):1277-302.
• S Hooshmand. J R Brisco, B H Arjmandi. The effect of dried plum on serum levels of receptor activator of NF-κB ligand, osteoprotegerin and sclerostin in osteopenic postmenopausal women: a randomised controlled trial. Br J Nutr. 2014 Jul 14;112(1):55-60.

Image thanks to bykst via Pixabay.