Osteoporotic bone micrograph

Thinning bones

Age, diet and exercise can contribute to thinning bones

Age and diet

Bone strength is maintained if bone is replaced at the same rate as old bone is removed. When the laying down of new bone cells slackens, the bones become thinner. In our late teens, the mass and density of our bones reaches its peak, then slowly declines with age. Older people, therefore, have thinner bones; combined with a decrease in muscle mass, this leaves elderly people prone to injuries from falls.

Some 75,000 broken hips are treated in the UK per year – mostly in older women. The depletion of bone is known as osteoporosis and is more common in women, probably because of hormonal changes linked to the menopause.

There is evidence that some fizzy drinks can speed up bone thinning. In one study, regular cola drinking was linked to lower bone density in women, for example, although the reasons for this are somewhat unclear. It could be because cola features in diets that are otherwise low in calcium or because such drinks contain phosphoric acid, which is known to bind to calcium and magnesium in the gut, reducing absorption of the minerals.


Weight-bearing exercise is protective against osteoporosis, and exercise in later life can also improve muscle strength and balance, reducing falls and osteoporosis-related injuries.

However, strenuous exercise can disturb the balance between bone removal and renewal, damaging bones even in the absence of osteoporosis. Athletes, if not careful, can put themselves at serious risk of stress fractures, leaving hairline breaks in bones put under load.

Lead image:

German Tenorio/Flickr CC BY


About this resource

This resource was first published in ‘Exercise, Energy and Movement’ in January 2012 and reviewed and updated in August 2016.

Cell biology, Physiology, Health, infection and disease
Exercise, Energy and Movement
Education levels:
14–16, 16–19, Continuing professional development