Osteoporosis is a chronic and preventable metabolic disease characterized by reduced bone mass and deterioration of bone structure, increasing the risk of fractures, disability, and mortality in older adults. Global studies show that about 20% of people over 50 have osteoporosis, and around 40% have low bone mass.
The Role of Nutrition and Dairy
Scientific nutrition, including adequate dairy consumption, plays a key role in prevention. Milk and dairy products provide calcium, phosphorus, high-quality proteins, vitamins, oligosaccharides, and exosomes—all of which support bone growth and health. Research has shown that dairy consumption can improve mineral absorption, enhance bone metabolism, and reduce inflammation and oxidative stress. However, some studies report mixed results, as most previous research focused on individual nutrients like calcium or vitamin D, rather than the synergistic effects of the complex nutrients in milk.
Pathogenesis of Osteoporosis
Osteoporosis develops when the balance between bone resorption (breakdown by osteoclasts) and bone formation (by osteoblasts) is disrupted. This imbalance arises from complex interactions among hormonal, genetic, inflammatory, epigenetic, and environmental factors. Menopause, aging, chronic inflammation, and overactive parathyroid function are among the most recognized causes. However, a full understanding of how genes, cells, signaling pathways, and environmental factors interact is still limited.
Milk Components in Bone Health
Milk contains vitamins, proteins, fats, lactose, and minerals that work together to improve calcium and phosphorus absorption, stimulate osteoblast activity, and suppress osteoclasts. The effects of milk components on bone health should be considered in combination rather than in isolation.
Key Components and Effects
Threshold Effects:
- Milk provides calcium and phosphorus in a balanced ratio (≈1.3:1). Consuming 700–1300 mg/day of calcium supports better absorption and reduces fracture risk.
- Vitamin D is essential for calcium absorption and bone density. Primary sources include fortified milk and sunlight. Benefits plateau at about 1000 IU/day.
Synergistic Effects:
- Milk proteins and fats enhance calcium absorption, stimulate osteoblasts, and reduce osteoclast activity. For example, whey proteins prevent calcium precipitation in the gut and increase absorption by 5–10%.
- Lactose and probiotics support gut microbiota, improving calcium and vitamin D absorption and overall bone health.
Gut–Bone Axis
The gut microbiome plays a crucial role in bone health. Aging can disrupt beneficial gut bacteria, reducing bone density. Milk components such as probiotics, prebiotics, and exosomes help regulate this gut–bone axis, supporting bone density and strength.
Conclusion
Bone health depends not only on calcium intake but also on the combined effects of various nutrients and bioactive compounds in milk. Their synergistic action helps reduce the risk of osteoporosis. Milk consumption—especially enriched, low-fat, lactose-free, or probiotic-fortified options—can enhance mineral absorption, support bone growth in children and adolescents, and maintain bone density in older adults.
In addition to dairy, other factors such as overall diet, physical activity, and intake of other nutrients also influence bone health. Therefore, a comprehensive nutritional strategy is essential for optimal bone health.
References:
Wang, Kaili et al. “New insights into dairy management and the prevention and treatment of osteoporosis: The shift from single nutrient to dairy matrix effects-A review.” Comprehensive reviews in food science and food safety vol. 23,4 (2024): e13374. DOI: 10.1111/1541-4337.13374
