This month’s interesting study revolves around prunes and bone density – that’s right, prunes. Those tiny dried pieces of fruit that we associate with old people and constipation. Prunes are well-known for being an excellent source of fiber and can help keep things "moving along" your digestive tract. I vividly remember a childhood vacation to my grandparents’ house where I was having bathroom ‘issues’. Grandma pulled me aside and handed me a glass of prune juice with a look on her face that said, “bottoms up”. Who knew she was potentially helping to strengthen my bones? Go Grandma!
New evidence suggests dried plums are more than a one-trick pony, boosting not only digestion but bone strength as well. The Prune Study  – a 12-month randomized control trial in postmenopausal women concluded that a 50-g daily dose of prunes can prevent the loss of total hip BMD (bone mineral density) in women after 6 months, which persisted for 12 months. Prunes aren’t particularly high in calcium, so I wondered how they were helping? The researchers, who tracked 235 older women for a year, speculated that the daily handful of prunes lowered inflammatory chemicals that contribute to bone breakdown. Curious, I dug further, and there were plenty of other studies linking prune consumption to bone density.  Findings from preclinical and clinical studies that have assessed the effect of prunes on oxidative stress, inflammatory mediators, and bone outcomes all highlighted the evidence supporting a role of prunes in modulating inflammation. Long story short, less inflammation equates to stronger bones. Dried plums (prunes) in whole form are an efficacious functional food therapy for preventing bone loss in postmenopausal women – and I’d guess in younger men and women as well.  Having had a less than ideal BMD score about 10 years ago, this is an issue close to my heart. Many of the female endurance athletes I’ve worked with, especially those with LEA and Red-S, suffer with low bone mineral density. Aside from strength training, Vitamin D supplementation, daily collagen intake and prescription medications many athletes discount whole food options for increasing or preventing loss of BMD.
Here are some other foods, rich in calcium, Vitamin D, and anti-inflammatory properties that can help support bone mineral density: milk, yogurt, cheese, dark leafy greens, broccoli and fortified foods like cereal. Almonds, plant milks and white canned beans all have around 200mg of calcium per serving. Two figs contain about 65 mg of calcium, canned salmon has 180mg, and a 4oz serving of tofu has a whopping 430mg of calcium. FYI – daily RDA for calcium is 1000-1300mg.
Back to the prunes, the tricky part becomes balancing their carb/sugar content with your training and body composition goals. 50g of prunes (as suggested by the studies) equals 120 calories, 32g carbs, and 19g sugar. They are right on the line of being a ‘red’ snack and could easily be added to pre/during training fuel as long as you don’t experience any GI issues. You could add some sliced prunes to oatmeal, smoothies, and yogurt. You could stash some in a pocket for a long-run snack or use prunes to make a sweet sauce for meats like pork.
And not that anyone asked, but here is my suggestion for the plum people – rebrand prunes to dried plums, change the messaging by getting some athletes to do ad’s like the ‘Got Milk’ ones only saying ‘Got Plums’, and start passing out packages of plums in endurance race swag-bags. The messaging could be “Take care of your bones… while also keeping yourself regular”. It really is a win-win!
KEY TAKE AWAY
So, what’s the takeaway? The power of food is unmatched and often under-utilised. There’s a reason Scott and I are constantly pushing greens and veggies at every meal. Whole foods have an almost unlimited potential to nourish and heal our bodies. You can supplement all day long but don’t neglect the everyday basic staples. Studies like this remind me that just when I think I know it all… I don’t.
 De Souza MJ, Strock NCA, Williams NI, Lee H, Koltun KJ, Rogers C, Ferruzzi MG, Nakatsu CH, Weaver C. Prunes preserve hip bone mineral density in a 12-month randomized controlled trial in postmenopausal women: the Prune Study. Am J Clin Nutr. 2022 Oct 6;116(4):897-910. doi: 10.1093/ajcn/nqac189. PMID: 35798020.
Damani JJ, De Souza MJ, VanEvery HL, Strock NCA, Rogers CJ. The Role of Prunes in Modulating Inflammatory Pathways to Improve Bone Health in Postmenopausal Women. Adv Nutr. 2022 Oct 2;13(5):1476-1492. doi: 10.1093/advances/nmab162. PMID: 34978320; PMCID: PMC9526830.
Arjmandi BH, Johnson SA, Pourafshar S, Navaei N, George KS, Hooshmand S, Chai SC, Akhavan NS. Bone-Protective Effects of Dried Plum in Postmenopausal Women: Efficacy and Possible Mechanisms. Nutrients. 2017 May 14;9(5):496. doi: 10.3390/nu9050496. PMID: 28505102; PMCID: PMC5452226.