RESEARCH AT HARVARD OVERTURNS TRADITIONAL THINKING

According to recent research, being very overweight could put you at risk of brittle bones.

Up until now scientists had thought that carrying a few extra pounds helped to protect bones and prevent fractures.

The researchers believe that instead of protecting bones, the extra fat triggers the formation of cells called osteoclasts which gradually wear them down. They also suspect that if large amounts of fat are stored within the bone it inhibits the production of new bone tissue.

Scientists had assumed that being obese protected bones as fat cells release the hormone oestrogen. This is known to encourage bones to absorb the mineral calcium from the diet, which makes them stronger.

But in the past few years a growing number of studies have dispelled this theory by showing that very overweight adults tend to have thinner bones and a lower bone density.

This latest study by academics at Harvard University in Boston has suggested a cause by claiming that high levels of fat in the bones gradually wear them down.

The research-lead on this study at Harvard Medical School, associate professor Miriam Bredella, said:

… Obesity was once thought to be protective against bone loss. We have found that this is not true. Bone marrow fat makes bones weak. If you have a spine that’s filled with fat, it’s not going to be as strong.

Her study – first published in the journal Radiology – looked at the bones and fat deposits of 106 obese men and women. The researchers used a type of scan called proton magnetic resonance spectroscopy to measure fat in the bone marrow, muscles and liver.

They found that adults with the most fat in their liver and muscles also had the highest levels of fat in their bone marrow, which increases the risk of osteoporosis.

More than three million people in Britain suffer from the disease for which there is no cure.

And in further developments, children as young as eight are showing signs of high blood pressure due to obesity.

Campaigners say these children are putting themselves at high risk of strokes, heart attacks and liver disease in adulthood and should watch their weight and salt intake.

Harvard academics looked at blood pressure readings, weights and diets of 8,300 children aged eight to 17 surveyed between 1999 and 2008. They compared their average results with those of a group of 3,200 similar-aged children who were studied from 1988 to 1994.

Girls in the most recent group were 53 per cent more likely to have higher than normal blood pressure. Some 12.6 per cent had higher than normal readings compared to 8.2 per cent of those surveyed earlier.

The proportion of boys with higher blood pressure rose from 15.8 per cent to 19.2 per cent, an increase of 21 per cent.

British scientists expect the US results would prove to be similar here as so many children are now obese.

A statement issued by the British Heart Foundation, said:

… It’s a real concern to see raised levels at such a young age. Unhealthy habits formed in childhood can be hard to shake off.