Now here's a conundrum.
Daughter no 1 (Martha's mum) has just told me that she's been told by medical professionals that too much dairy (calcium) consumption causes osteoporosis. This seems counter-intuitive. So far as I understand it, the science is like this: throughout one's life, osteoblasst produce bone whereas osteoclasts break bone down. One's bone mineral density is therefore in a constant state of flux.
However, in major dairy consuming countries (US, UK) there is, apparently, more osteoporosis and greater incidence of hip fractures in the elderly than in countries with much lower dairy intake. Some of this can be attributed to obesity and largely sedentary lifestyles causing more falls, and worse consequences of those falls.
The other consideration is that osteoblasts and osteoclasts have limited lives, and like all cells, their production slows down dramatically as you get older. A high calcium intake in early life will therefore lead to a high BMD but an earlier loss of osteoblasts will result in a much larger drop-off of bone density in old age. In countries with much lower dairy consumption, the theory is that their osteoblasts don't die so fast so when they reach an advanced age their bone mass is still being replaced.
Oestrogen and testosterone production both have an effect, the former more so, which is why 80% of osteoporosis sufferers are women. Also, oestrogen reduces in women at a younger age than testosterone in men, so whereas in women the onset of osteoporosis tends to be at the menopause (late 40s / early 50s) in men it's about 10 years later. I'm 57next month.
I suppose the most reliable remedy is to increase my sexual activity.
