Nacre may combat cortical bone loss and improve bone strength to reduce risk of fragility fractures.
Dietary nacre supplements could be used for older adults with osteoporosis, according to the results of a mouse study recently published by investigators in Experimental Gerontology. This mollusk-derived compound was shown to improve cortical bone strength, reduce bone porosity, and reduce bone loss, and it may have a significant therapeutic role for reducing injury and morbidities related to osteoporosis.1
“Fracture due to bone fragility imposes a significant health care burden on society,” wrote study authors in the article. “Preventive strategies focused on cortical bone loss… [that are] provided at earlier stages should reduce the risk of fractures.”
Both men and women are at risk of fragility and fragility fractures associated with aging. Many new therapeutics are aimed at reducing risk of bone loss and injury, and new research suggests nacre—a calcium carbonate-based material embedded in organic compounds that is derived from the exoskeleton of mollusks—could join the circulation.
In preclinical studies, nacre benefitted patients with osteoporosis; however, these prior studies zeroed in on it being used for bone loss caused by estrogen deficiency in younger animals.
In this study, investigators evaluated the pathophysiology of osteoporosis (which primarily affects older adults) and looked at dietary nacre for bone loss caused by aging. It is unique from prior studies, seeing that it evaluates the supplement for bone loss related to aging and does not highlight sex-hormone deficiency.
“[While] both aging and sex steroid deficiency cause osteoporosis… their impact on the skeleton are mechanistically distinct and concurrently occur in the livings,” authors wrote in the article.
During this study, investigators randomized female mice into groups to receive 1) a nacre supplement for 90 days, 2) a standard diet with no supplement, or 3) a daily calcium carbonate (CaCO3) supplement.
The team observed that nacre supplementation was associated with less expression of genes,which are associated with osteoclast activity; osteoclasts are cells which degrade bone and worsen bone loss in patients with osteoporosis.1,2
During the study, mice in the nacre arm also developed better cortical bone strength (in the cortex) than mice on a standard or CaCO3 diet (p < 0.05). Moreover, nacre reduced cortical bone loss. These observed benefits could make it especially impactful for older women with osteoporosis because they are susceptible to fragility fracture caused by bone loss.
“Aging contributes to the slow phase of bone loss in women that continues indefinitely,” wrote study authors in the article. “During this phase, the cortical bone loss is dominant, and induces risk of fragility fractures.”
Nacre supplementation might also reduce cortical porosity, which occurs with old age, and may mitigate any age-related reduction in bone cells. Although it did not improve trabecular bone loss (which also deteriorates because of aging) nacre did not contribute to worsening condition.
The study includes limitations, such as its smaller sample size. Additionally, researchers still cannot explain why nacre might affect the cortical bone. Further, researchers did not moderate food intake, so they cannot fully explain body weight and composition changes.
Study authors wrote, “Collectively, these data suggest that dietary nacre should be a potential candidate for reducing aging-associated cortical bone loss in the elderly.”
1. Nguyen DK, Vanden-Bossche A, Laroche N, et al. Dietary supplementation with nacre reduces cortical bone loss in aged female mice. Exper Gero. 2023(184);doi:10.1016/j.exger.2023.112337.
2. Boyce BF, Yao Z, Xing L. Osteoclasts have multiple roles in bone in addition to bone resorption. Crit Rev Eukaryot Gene Expr. 2009;19(3):171-80. doi:10.1615/critreveukargeneexpr.v19.i3.10