The effect of milk consumption on bone and fracture incidence, an update

The effect of season and agro-ecology on physicochemical properties of cow's raw milk in Central and North-Western Zone of Tigray, Ethiopia

Milk at a normal state has unique physical, chemical, and biological characteristics that are used as quality indicators. The quality of milk is influenced by many factors and the components of milk are very sensitive indicators for milk production practices. Season and agro-ecologies have influences on physicochemical properties of cow milk. Therefore, this research aimed to investigate the effect of season and agro-ecology on the physicochemical properties of cow's raw milk in Central and North-Western Zone of Tigray. The study was conducted in Aksum, Shire-Indaselassie, and Sheraro administrative towns. A two-stage sampling method was used to select both the study area and respondents. All towns in the Central and North-Western zones of Tigray were categorized into three agro-ecologies, and sample towns were purposively selected from each category based on accessibility and milk production potential. Sample respondents were then randomly selected from each agro-ecology. Agro-ecology categorization was based on altitude, temperature, and feeding practices, while seasons were classified according to rainfall and temperature. A total of 210 samples, comprising 35 samples from dairy farms and 35 samples from cafeterias within each agro-ecology, were analyzed to assess the physicochemical properties of cow milk across two different seasons. Physicochemical analysis including determination of fat, crude protein, solids not fat, density, lactose, salt, water added and freezing point was conducted in the laboratory of Mekelle University using Lacto scan, Bulgaria. The overall mean values of milk fat, solids-not-fat (SNF), protein, and lactose were 3.72 ± 0.12 %, 6.72 ± 0.17 %, 2.6 ± 0.08 %, and 3.72 ± 0.09 %, respectively. Specific gravity, salt content, water added, and freezing point exhibited mean values of 1.026 ± 0.001 g/ml, 0.53 ± 0.01 %, 19.33 ± 1.8 %, and -0.42 ± 0.01oC, respectively. Significant differences (p < 0.05) were observed in protein, solids-not-fat, lactose, and salt content among agro-ecologies, seasons, and sources of milk. Correlation analysis revealed positive correlations between specific gravity and solids-not-fat, protein, lactose, and total salt, while negative correlations were observed with water added and freezing point (p ≤ 0.01). In conclusion, the physical and chemical properties of cow's raw milk are influenced by agro-ecology, season, and the source of milk. Notably, milk adulteration, particularly with the addition of water, was more prevalent among cafeteria owners. Given the absence of established milk quality standards in Ethiopian conditions, it is imperative for the government to introduce quality standard measures, rules, and regulations to effectively control milk quality.

Association between Dairy Product Intake and Risk of Fracture among Adults: A Cohort Study from China Health and Nutrition Survey

Background: The current literature reports inconsistent associations between dairy product intake and fracture. This study assessed the association between dairy product intake and the risk of fracture among Chinese adults and examined the mediation effects of height and body mass index (BMI) on the association. Methods: Data in 1997−2015 from the China Health and Nutrition Survey were used. Dietary data were collected by a 24-hour dietary recall, and occurrences of fracture were obtained by self-report of participants. Cumulative average intake of daily dairy products was calculated by the sum of the dairy product intake and divided by the total waves of participating in the surveys before fracture. Cox proportion hazard regressions were performed to explore the associations between dairy product intake and the risk of fracture. Mediation analysis models were established to examine the mediation effects of height and BMI on the associations. Results: A total of 14,711 participants were included. Dairy product intake of 0.1−100 g/day was associated with a decreased risk of fracture, while no association was observed among participants with dairy product intake of >100 g/day. The indirect effects of dairy product intake on the fracture mediated by height and BMI were much smaller than the direct effects. Conclusions: Dairy product intake with 0.1−100 g/day is associated with a lower risk of fracture, and the association is mainly a direct result of nutrients in dairy products and much less a result of the mediation effects of height or BMI. Dairy product intake of 0.1−100 g/day might be a cost-effective measure for Chinese adults to decrease fracture incidence.

Kefir Peptides Prevent Estrogen Deficiency-Induced Bone Loss and Modulate the Structure of the Gut Microbiota in Ovariectomized Mice

Osteoporosis is a major skeletal disease associated with estrogen deficiency in postmenopausal women. Kefir-fermented peptides (KPs) are bioactive peptides with health-promoting benefits that are produced from the degradation of dairy milk proteins by the probiotic microflora in kefir grains. This study aimed to evaluate the effects of KPs on osteoporosis prevention and the modulation of the composition of the gut microbiota in ovariectomized (OVX) mice. OVX mice receiving an 8-week oral gavage of 100 mg of KPs and 100 mg of KPs + 10 mg Ca exhibited lower trabecular separation (Tb. Sp), and higher bone mineral density (BMD), trabecular number (Tb. N) and bone volume (BV/TV), than OVX groups receiving Ca alone and untreated mice, and these effects were also reflected in bones with better mechanical properties of strength and fracture toughness. The gut microbiota of the cecal contents was examined by 16S rDNA amplicon sequencing. α-Diversity analysis indicated that the gut microbiota of OVX mice was enriched more than that of sham mice, but the diversity was not changed significantly. Treatment with KPs caused increased microbiota richness and diversity in OVX mice compared with those in sham mice. The microbiota composition changed markedly in OVX mice compared with that in sham mice. Following the oral administration of KPs for 8 weeks, the abundances of Alloprevotella, Anaerostipes, Parasutterella, Romboutsia, Ruminococcus_1 and Streptococcus genera were restored to levels close to those in the sham group. However, the correlation of these bacterial populations with bone metabolism needs further investigation. Taken together, KPs prevent menopausal osteoporosis and mildly modulate the structure of the gut microbiota in OVX mice.

Milk Consumption for the Prevention of Fragility Fractures

Results indicating that a high milk intake is associated with both higher and lower risks of fragility fractures, or that indicate no association, can all be presented in the same meta-analysis, depending on how it is performed. In this narrative review, we discuss the available studies examining milk intake in relation to fragility fractures, highlight potential problems with meta-analyses of such studies, and discuss potential mechanisms and biases underlying the different results. We conclude that studies examining milk and dairy intakes in relation to fragility fracture risk need to study the different milk products separately. Meta-analyses should consider the doses in the individual studies. Additional studies in populations with a large range of intake of fermented milk are warranted.

The Belgian Bone Club 2020 guidelines for the management of osteoporosis in postmenopausal women

PURPOSE

To provide updated evidence-based guidelines for the management of osteoporosis in postmenopausal women in Belgium.

METHODS

The Belgian Bone Club (BBC) gathered a guideline developer group. Nine "Population, Intervention, Comparator, Outcome" (PICO) questions covering screening, diagnosis, non-pharmacological and pharmacological treatments, and monitoring were formulated. A systematic search of MEDLINE, the Cochrane Database of Systematic Reviews, and Scopus was performed to find network meta-analyses, meta-analyses, systematic reviews, guidelines, and recommendations from scientific societies published in the last 10 years. Manual searches were also performed. Summaries of evidence were provided, and recommendations were further validated by the BBC board members and other national scientific societies' experts.

RESULTS

Of the 3840 references in the search, 333 full texts were assessed for eligibility, and 129 met the inclusion criteria. Osteoporosis screening using clinical risk factors should be considered. Patients with a recent (<2 years) major osteoporotic fracture were considered at very high and imminent risk of future fracture. The combination of bone mineral density measured by dual-energy X-ray absorptiometry and 10-year fracture risk was used to categorize patients as low or high risk. Patient education, the combination of weight-bearing and resistance training, and optimal calcium intake and vitamin D status were recommended. Antiresorptive and anabolic osteoporosis treatment should be considered for patients at high and very high fracture risk, respectively. Follow-up should focus on compliance, and patient-tailored monitoring should be considered.

CONCLUSION

BBC guidelines and 25 guideline recommendations bridge the gap between research and clinical practice for the screening, diagnosis, and management of osteoporosis.