You probably hadn’t realised it, but you don’t just lose height with the passing of the years – it changes on a daily basis. You can test this for yourself by measuring how tall you are in the morning and again at night. You should lose about 1 cm over the course of the day; because during the day, the force of gravity pulls your body down, compressing your spine and other body parts. There are 23 jelly-like intervertebral discs that act as shock absorbers between the hard vertebral bones. Throughout the day, the compressed discs squeeze out fluid and get slightly smaller. When you lie down at night, these discs can reabsorb the fluid like a sponge and expand, restoring you to full height come the morning. Astronauts in space can experience the reverse of this effect: due to the lack of gravity they can grow up to 7cm as their spines stretch out.
As our bodies age we can experience permanent height loss. On average, we permanently lose about 1cm every decade after the age of forty. This occurs because as we get older our bodies’ ability to repair decreases; the intervertebral discs stiffen and flatten and are less able retain the fluid that keeps them soft and jelly-like. Muscles also lose mass and weaken, especially in the abdomen and back, which can exacerbate a stooped posture. Even the arches of the feet flatten slightly reducing your height by a few more precious millimetres.
We might not be able to control all these things that happen to us as we age but there are some habits we can change to prevent losing inches as the years go by. A lack of exercise, smoking, drinking too much alcohol or caffeine excessively and poor nutrition can all lead to a loss of height. Such unhealthy habits can increase the rate of bone density loss that occurs naturally as we age. For some people this can lead to osteoporosis, a condition that weakens bones causing them to become more fragile and break more easily.
Elderly people who are permanently shortened and hunched forward have often suffered compression and wedge fractures of the vertebrae due to osteoporosis – the result of a spine no longer strong enough to support the weight of the body. Research has shown that a good diet throughout your life reduces your risk of osteoporosis: eating foods high in calcium and vitamin D such as dairy, fruits and vegetables can help keep your bones strong. Of course, if you get really desperate, you could always try living in space if you fancy growing a few inches as you get older. Just don’t expect it to last when you come home.
Answer by Nathan Beal
Photo credit: Paris, Old men crosses slowly by Julie Kertesz, on Flickr
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