Your grandparents were right. Eating prunes daily is good for your digestive and bone health. In 2 recent studies, researchers found that eating prunes preserved bone density in postmenopausal patients and may prevent osteoporosis.

Regular consumption of prunes was associated with a significant reduction in proinflammatory cytokines, markers of inflammation that can contribute to bone loss in postmenopausal women, according to the first study presented by researchers from The Pennsylvania State University at the American Physiological Society (APS) annual meeting at Experimental Biology 2022 in Philadelphia.1 Findings from the second study by this research group suggest that daily prune consumption preserved bone mineral density (BMD) at the hip and protected against increased fracture risk in postmenopausal women, as reported at the World Congress on Osteoporosis, Osteoarthritis and Musculoskeletal Diseases held virtually on March 24 to 26, 2022.2

Previous research has shown that polyphenol extracts—plant compounds that act as antioxidants and reduce inflammation—in prunes promote lower levels of oxidative stress and inflammation in osteoclasts. In the first randomized controlled trial, researchers explored the effects of 2 doses of a nutritional intervention using prunes on markers of inflammation and bone health after menopause.


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Postmenopausal women (n=106; aged 55 to 75 years) were randomly assigned to eat 50 grams or 100 grams of prunes daily (approximately 6 and 12 prunes, respectively) or no prunes for 12 months. All participants also received 1200 mg calcium and 800 IU vitamin D3 daily. No significant differences in baseline characteristics were found among the 3 study groups.

Prunes Reduce Proinflammatory Cytokine Levels

Blood samples taken before and after the trial showed significant reductions in proinflammatory cytokine levels in both groups that consumed prunes. Participants given 100 grams of prunes daily showed significant reductions from baseline in interleukin (IL)-1β (P =.013), IL-6 (P =.007), and IL-8 (P =.049) secretion. Participants who received 50 grams of prunes daily showed a significant reduction from baseline in tumor necrosis factor (TNF)-α (P <.001) secretion from lipopolysaccharide-stimulated peripheral blood mononuclear cells compared with those in the control group.

Prune consumption did not alter serum C-reactive protein (CRP) level or number of circulating monocytes.

Effects of Prunes on Bone Density in Women With Osteoporosis

In the second randomized controlled trial, 235 women with a bone mineral density T-score of -3.0 at any site were randomly assigned to consume 50 grams of prunes daily, 100 grams of prunes daily, or no prunes for 12 months. The dropout rate was markedly higher (41%) in the group that consumed 100 grams of prunes than in the 50-g group and control group (10% and 15%, respectively).

Total hip bone mineral density decreased significantly in the control group at 6- and 12-month follow-up compared to baseline (both P <0.05). In contrast, the 50-g prune group showed preserved bone mineral density at both time points. The FRAX hip fracture risk score was maintained in the pooled groups who consumed prunes but worsened in the control group at 6 months.  

“It is exciting that the data from our large randomized controlled trial in postmenopausal women showed that consuming 5 to 6 prunes a day demonstrated the benefit of protecting from bone loss at the hip,” said principal investigator Mary Jane De Souza, PhD, FACSM, distinguished professor, The Pennsylvania State University.3 “Our data supports the use of prunes to protect the hip from bone loss postmenopause. Indeed, this data may be especially valuable for postmenopausal women who cannot take pharmacological therapy to combat bone loss and need an alternative strategy.”

Both of the studies were supported by the California Prune Board. Two of the researchers are members of the Nutrition Advisory Panel for the California Prune Board.

Sources

1. Damani J, Strock N, De Souza MJ, Rogers C. A randomized controlled trial of dietary supplementation with prunes (dried plums) on inflammatory markers in postmenopausal women. Presented at: American Physiological Society (APS) annual meeting at Experimental Biology 2022; April 2-5, 2022; Philadelphia, PA: poster E346

2. De Souza, MJ, Strock NC, Willians NI, et al. Prunes preserve hip bone mineral density and FRAX risk in a 12-month randomized controlled trial in postmenopausal women: the prune study [Abstract presentation]. Presented at: World Congress on Osteoporosis, Osteoarthritis and Musculoskeletal Diseases; March 24-26, 2022: OC17. https://virtual.wco-iof-esceo.org/.

3. Prunes prevent bone loss at hip and protect against fracture risk. News release. Eurekalert; March 28, 2022. Accessed March 29, 2022. https://www.eurekalert.org/news-releases/947810

This article originally appeared on Clinical Advisor