Bone-Protective Effects of Dried Plum in Postmenopausal Women: Efficacy and Possible Mechanisms

Abstract

Osteoporosis is an age-related chronic disease characterized by a loss of bone mass and quality, and is associated with an increased risk of fragility fractures. Postmenopausal women are at the greatest risk of developing osteoporosis due to the cessation in ovarian hormone production, which causes accelerated bone loss. As the demographic shifts to a more aged population, a growing number of postmenopausal women will be afflicted with osteoporosis. Certain lifestyle factors, including nutrition and exercise, are known to reduce the risk of developing osteoporosis and therefore play an important role in bone health. In terms of nutrition, accumulating evidence suggests that dried plum (Prunus domestica L.) is potentially an efficacious intervention for preventing and reversing bone mass and structural loss in an ovariectomized rat model of osteoporosis, as well as in osteopenic postmenopausal women. Here, we provide evidence supporting the efficacy of dried plum in preventing and reversing bone loss associated with ovarian hormone deficiency in rodent models and in humans. We end with the results of a recent follow-up study demonstrating that postmenopausal women who previously consumed 100 g dried plum per day during our one-year clinical trial conducted five years earlier retained bone mineral density to a greater extent than those receiving a comparative control. Additionally, we highlight the possible mechanisms of action by which bioactive compounds in dried plum exert bone-protective effects. Overall, the findings of our studies and others strongly suggest that dried plum in its whole form is a promising and efficacious functional food therapy for preventing bone loss in postmenopausal women, with the potential for long-lasting bone-protective effects.

Keywords: (poly)phenols; bioactive compounds; functional foods; menopause; nutrition; osteopenia; osteoporosis; polyphenols; prune.

Figure 1

(A) Effects of ovariectomy and dried plum on bone density of right femur; (B) Effects of ovariectomy and dried plum on bone density of 4th lumbar spine. Bars represent mean ± standard error of the mean. Bars that do not share the same letters are significantly (p < 0.05) different from each other. BMD, bone mineral density; HD, high dose (25%) dried plum; LD, low dose (5%) dried plum; Ovx, ovariectomized; Sham, sham-operated.

Figure 2

(A) Effects of ovariectomy, dried plum, and estrogen on bone density of right femur; (B) Effects ovariectomy, dried plum, and estrogen on bone density of 4th lumbar spine. Bars represent mean ± standard error of the mean. Bars that do not share the same letters are significantly (p < 0.05) different from each other. BMD, bone mineral density; E₂, 17β-estradiol, LD, low dose (5%) dried plum; high dose (25%) dried plum; MD, medium dose (15%) dried plum; Ovx, ovariectomized; Sham, sham-operated.

Figure 3

Representative images of proximal tibia demonstrating the effect of ovariectomy, dried plum, and estrogen on trabecular bone structure. E₂, 17β-estradiol; LD, high dose (25%) dried plum; low dose (5%) dried plum; MD, medium dose (15%) dried plum, Ovx, ovariectomized; Sham, sham-operated.

Figure 4

Change from baseline (ratio) in bone mineral density (BMD) from baseline to one-year following daily consumption of 100 g dried plum or 75 g dried apple. Bars represent mean ± standard error of the mean. * Denotes significant (p < 0.05) difference between groups.

Figure 5

Bone mineral density (BMD) of the (A) ulna and (B) lumbar spine five years following one-year intervention study with daily consumption of 100 g dried plum or 75 g dried apple. Bars represent mean ± standard error of the mean. * Values were significantly (p < 0.05) different between groups.