Eggshell-Fortified Meals: A New Hope for Bone Health in Postmenopausal Women

Calcium intake in Asian countries such as China, India, Japan, and Korea has been reported to be significantly low, ranging from 300 to 600mg per day. This deficiency is linked to a higher risk of fractures in older women. With the menopausal transition causing a drop in estrogen levels, the intake of essential nutrients like calcium and vitamin D becomes even more crucial.

While milk and dairy products are traditional sources of dietary calcium, the high incidence of lactose malabsorption in Asians necessitates alternative calcium sources. This need has led to innovative approaches like the use of eggshells, which are composed primarily of calcium carbonate and can provide about 39% calcium.

In an effort to address this nutritional gap, Korean researchers conducted a study to determine the effect of eggshell and vitamin D-fortified Home Meal Replacements (HMRs) on bone mineral density (BMD) in postmenopausal women.

The Study

Funded by the Ottogi Ham Taiho Foundation, the study was a randomized, double-blind, controlled intervention involving participants aged 50 to 64. The study divided participants into two groups over a six-month period, with one group consuming three ready-to-heat HMRs weekly that were fortified with eggshell powder and vitamin D, and the other group consuming non-fortified HMRs.

The fortified HMRs included curry, black bean sauce, and sweet pumpkin porridge, with tomatoes added to the curry only for the treatment group. The aim was to evaluate whether these fortified meals could improve calcium and vitamin D intake and subsequently reduce the decline in femoral neck BMD.

Key Findings

At the start of the study, calcium and vitamin D intake were inadequate in both groups. However, during the intervention, participants in the treatment group consumed an additional 261mg of calcium and 10.3μg of vitamin D per day from the HMRs, meeting the recommended intake levels.

After six months, the treatment group exhibited a significantly smaller decrease in femoral neck BMD compared to the control group. No significant differences were observed in other bone markers between the two groups.

Implications and Future Directions

The study demonstrated that consuming eggshell powder- and vitamin D-fortified HMRs three times a week for six months to a year effectively prevents rapid declines in femoral neck BMD in postmenopausal women. This suggests that a daily diet containing adequate amounts of natural calcium and vitamin D can help prevent bone loss and fractures, particularly in populations with low dairy consumption.

Opportunities for Functional HMRs

The incidence of osteoporosis among postmenopausal women is notably high, with 38.4% in Korea and 30.3% in China. As demand for functional, customized HMRs rises in line with health and wellness trends, these products could be a practical solution to increase the intake of bone-support nutrients.

Participants in the study tolerated the HMRs well, with no adverse events reported. The study also highlighted the potential of eggshells as an inexpensive calcium source for those who have difficulty consuming dairy products. Additionally, the fortification with carotenoids, such as lutein and beta-carotene, provided added health benefits, including antioxidant and anti-inflammatory properties.

However, the study's limitations include a small sample size and the lack of quantitative exercise measurements among participants. Future research should explore larger-scale interventions and the complementary effects of foods like tomatoes on bone health.

Conclusion

This pioneering study on fortified HMRs offers a promising dietary strategy for sustainable calcium intake and bone health maintenance in postmenopausal women. By integrating natural sources of calcium and vitamin D into regular diets, particularly for populations vulnerable to nutrient deficiencies, such innovative approaches could significantly impact public health.