Research suggests older women who eat chocolate
daily could have lower bone density.
Photo by iStockphoto.

Could a cup of tea and a piece of dark chocolate be a recipe for good health? With the amount of information available on the pros and cons of both, most people could be forgiven for being confused.
 
Both are said to be rich in beneficial plant compounds called flavonoids and while good press for the antioxidants in dark chocolate have raised the hopes of chocoholics everywhere, recent studies have shown that most of the health-giving compounds, even in dark chocolate, are removed by manufacturers because of their bitter taste.
Now population-based studies led by Jonathan Hodgson at the University of Western Australia are shedding some light on what he says is a very complex area.

While Dr Hodgson and his team discovered that elderly women who drank tea had higher bone density and less bone loss than women who didn’t, another investigation found that eating chocolate on a daily basis appears to do the opposite.

Both studies were part of a larger long-term study of calcium supplements and bone health that is being led by Dr Richard Prince at Sir Charles Gairdner Hospital.

For the chocolate consumption investigation, recently published in the American Journal of Clinical Nutrition, the team examined the chocolate eating habits of 1,001 women between the ages of 70 and 85.

Using X-ray evidence, they concluded that the women who ate chocolate less than once a week for five years had better bone density than those who ate it every day.

So are we to conclude that the beneficial effects of tea could cancel out the apparent detrimental effects of chocolate?

Dr Hodgson refuses to be drawn, saying far more research is needed.

“I think we will probably still be investigating these questions in 100 years’ time,” he says.

“This was just a population study and we can really only say that higher chocolate consumption was associated with lower bone density. There are three ways to take these results: we can say this is happening via a mechanism that we can only speculate on; or that this is just a chance finding; or that it’s associated with other factors such as lifestyle.”

Some researchers have suggested that the results could be due to chocolate containing a substance called oxalate, which can reduce calcium absorption, and sugar, which enhances calcium excretion.

“It’s a very complex thing to narrow down,” Dr Hodgson says. “Even with something like tea, which is relatively simple because it is just one plant, there are hundreds of different compounds. It may have activity from dozens of different flavonoids.

“If studies in the US and Europe find a similar relationship between chocolate and bone density, then we can say there seems to be something here… Media reports tend to take one extreme or the other – chocolate is fantastic or chocolate is terrible. I suspect that it is somewhere in the middle.”

Meanwhile, Dr Hodgson is again investigating tea, this time via a population study into the long-term impacts of drinking tea on heart health.

“Population studies conducted during the past decade have shown that drinking tea is associated with a lower risk of heart disease,” he says.

“In the short term it has been shown to improve blood vessel dilation, but we want to confirm that it works over the longer term. Do the benefits continue over many months and are there any additional cardiovascular benefits when drinking tea over the longer term?”