Osteoporosis
A bone disease characterised by reduced density and deterioration of bone structure, increasing the risk of fractures, particularly common after the menopause.
Bone is not a fixed structure: it is a living tissue in constant renewal (remodelling). Some cells break down old bone (osteoclasts) while others build new bone (osteoblasts). Osteoporosis occurs when breakdown outpaces building.
Bone capital builds up until about age 30 (peak bone mass), then declines. In women, the drop in oestrogen at the menopause sharply accelerates the loss (oestrogen slows bone breakdown).
An original angle (beyond calcium): the message “drink milk for your bones” is reductive. Bone health depends on an orchestra of nutrients
- Calcium: the raw material (but an excess without cofactors goes to the arteries, not the bones)
- Vitamin D: calcium absorption
- Vitamin K2: directs calcium to the bones and away from the arteries (an often forgotten nutrient!)
- Magnesium: bone structure and activation of vitamin D
- Protein: about 50% of bone volume is protein (collagen)
A paradox: countries with high milk consumption (the Nordic countries) paradoxically have high fracture rates, a sign that calcium alone is not enough and that other factors (low vitamin D, genetics, activity) count.
The most powerful and underestimated lever is weight-bearing physical activity (walking, resistance training, jumping). Bone strengthens under mechanical stress: “use it or lose it”. Exercise often beats calcium supplements for preventing fractures.