16th February 2024
New study adds to the research connecting prunes and healthier bones
As women age, their bones can lose density and strength, but studies are showing how eating prunes every day may help make a difference.
A newly published study in Osteoporosis International shows that postmenopausal women who ate prunes daily for a year preserved certain measures of bone structure and estimated bone strength as compared to women who didn’t eat prunes[1]. The study adds to an accelerating body of published research that demonstrates eating prunes daily can help mitigate bone loss in older age.
“Prunes have a combination of minerals, vitamin K, phenolic compounds, fibre and anti-inflammatory properties that is unique among foods and in fact, unique among fruit,” said lead study author Mary Jane De Souza, Ph.D., a Distinguished Professor in the Department of Kinesiology at Pennsylvania State University. “We’ve been studying prunes because their combination of nutrients seems to work together for a positive effect on bones. While medication and hormone therapies can help women maintain their bone density and strength as they get older, these often require lifelong management and come with some risks – so learning about impactful dietary changes can be a great help.”
These findings are part of The Prune Study, a large, single-centre, parallel-arm, 12-month randomised controlled trial completed with 183 postmenopausal women who ranged in age from 55 to 75, who were nonsmokers and not severely obese[2].
Easy ways to eat prunes more often
Authors of The Prune Study have noted “high compliance and retention” over 12 months in women who ate 50 grams prunes a day — in other words, the women who participated tended to enjoy eating the prunes daily and tended to remember to eat them each day, which isn’t always the case in nutrition studies when the dietary changes are too hard or don’t taste good.
“Eating prunes is an easy thing to do – they’re sweet and satisfying,” said Leslie Bonci, MPH, RD, CSSD, LDN, a registered dietitian. “They fly under the radar for many people, but if you’re looking to add a healthy habit to your day, a serving of prunes is under 100 calories and easy to include at breakfast or paired with an easy protein source as a snack.”
Bonci offers these tips for including prunes in everyday eating:
- Breakfast is an ideal time for many people to establish a healthy routine. Try whole or sliced prunes on top of low-fat yogurt, wholemeal toast or porridge.
- For a balanced snack that will help provide energy over a few hours, pair prunes with a source of protein and healthy fat like nuts or cheese.
- If you have an afternoon sweet tooth, snack on prunes instead of a higher carb treat like a biscuit. Studies show that people who ate prunes in place of these other foods not only got more nutrients, they also felt satisfied and fuller for longer and ate less at their next meals[3].
- Prunes add sweet flavour and luxurious texture to dinner recipes, too. Try slicing or dicing them (use a wet knife to help with the stickiness) and stirring them into caramelised onions as a deeply flavoured, sweet and savoury topping for roast chicken, green beans or winter squash.
More information about the newly published study
This most recent publication from The Prune Study included 183 post-menopausal women who completed the one-year investigation and were separated into three test groups: a no prune diet, a 50 gram daily prune diet, or a 100 gram daily prune diet. Beyond the daily prune consumption requirements, participants did not follow any specific diet, but all (including the no prune diet group) consumed a daily requirement of 1,200 mg of calcium and 800 IU vitamin D through diet plus supplements.
To assess bone health and bone changes, a peripheral quantitative computed tomography (pQCT) scan was given to participants every six months. This test, unlike the better-known DEXA scan that measures bone density, can differentiate between different types of bones (e.g. trabecular bone and cortical bone) and provide a 3-dimensional assessment of specific bone health measurements including bone volume, bone structure and estimated bone strength.
Findings showed that compared to diets without prunes, when participants ate at least 50 grams of prunes daily over the one-year period, estimated bone strength was significantly maintained in the shin bone (tibia), where there is a combination of both trabecular and cortical bone present.
“Through these types of studies, it’s becoming clearer that different types of bones, and where they are found in the body, may impact our ability to maintain bone integrity, which is key to long term bone health,” said Dr. De Souza. “While the hip and spine are typical areas to diagnose for osteoporosis/osteopenia, the three-dimensional pQCT scans offer an additional informative picture of bone. The approach taken in this study helps to get ahead of a bone disease diagnosis, and better pinpoint and manage specific changes to bone structure, density, and estimated strength.”
Prunes’ health benefits beyond bone health
Ends
[1] Koltun KJ, Strock NCA, Weaver C., Hang L, Williams NI, Rogers CJ, Damani J, Ferruzzi MG, Nakatsu CH & De Souza MJ. Prunes preserve cortical density and estimated strength of the tibia in a 12-month randomized controlled trial in postmenopausal women: The Prune Study. Osteoporos Int (2024).
[2] De Souza MJ, Strock NCA, Rogers CJ, Williams NI, Ferruzzi MG, Nakatsu CH, Simpson AMR, Weaver C. Rationale and study design of Randomized Controlled Trial of Dietary Supplementation with prune (dried plums) on bone density, geometry, and estimated bone strength in postmenopausal women: The Prune study. Contemp Clin Trials Commun. 2022 May 28;28:100941. doi: 10.1016/j.conctc.2022.100941. PMID: 35669487; PMCID: PMC9163423.
[3] Harrold JA, Sadler M, Hughes GM, Boyland EJ, Williams NJ, McGill R, et al. Experimental studies and randomised controlled trial investigating the impact of traditional dried fruits consumed as snacks on food intake, experience of appetite and bodyweight. Nutrition Bulletin. 2021 Oct;46, 451– 467