Can a daily bar of chocolate cause brittle-bone disease?


Last updated at 17:13 25 January 2008

Women already feel guilty about eating chocolate in case it makes them fat.

Now comes more bad news - regular consumption could lead to weaker bones and osteoporosis.

This could mean a greater chance of fractures.

Women who ate chocolate every day were found to have less dense bones than those who ate it less than once a week, in a study by scientists at the University of Western Australia.

Head researcher Dr Jonathan Hodgson said: "Cocoa and chocolate have been promoted as having a range of beneficial cardiovascular properties.

"But the effect of chocolate intake on other organ systems has not been studied."

He added: "These findings could have important implications for prevention of osteoporotic fracture."

For the study, scientists monitored the amount of chocolate eaten over several weeks by 1,001 women aged 70 to 85.

Dr Hodgson and his colleagues from the University of Western Australia then measured the bone density and strength of each woman using X-rays.

The researchers found the women who ate chocolate less than once a week had significantly stronger bones than those who consumed the treat on a daily basis.

Low bone density was found in the hips, neck, tibia and heel bones of the women surveyed.

The researchers believe the findings may be because chocolate contains oxalate, which can reduce calcium absorption, and sugar, which is linked to calcium excretion.

Calcium is vital for maintaining healthy bones.

The study is published this month in the American Journal of Clinical Nutrition.

It comes less than a month after British medical journal The Lancet warned against viewing chocolate as a health food.

The Lancet article said consumers are generally unaware that manufacturers often remove the healthy element - the flavanols - because of their bitter taste.

As a result, it said, dark chocolate might contain no flavanols while at the same time being rich in fat and sugar, which are both potentially harmful to heart and arteries.

"Consumers are kept in the dark about flavanol content of chocolate because manufacturers rarely label their products with this information," it said.

The article followed research published the month before in the journal Circulation, which showed that flavanol-rich chocolate had a beneficial effect on circulation.

In a study by the Cardiovascular Centre in Zurich, it was found that flavanol-rich chocolate caused blood vessels to open up and improved heart function in 11 heart-transplant patients.