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26 August 2010

Dark chocolate bits may protect women against heart failure

Eating a small amount of high-quality dark chocolate one to three times a month may help stave off heart failure in women, a new Harvard study suggests.
But if you ingest too much "good" chocolate, that protective effect goes away, according to the researchers who report their finding in the Aug. 17 issue of Circulation: Heart Failure.

"Up until now, (researchers) were focused on other outcomes, such as the effects on blood pressure and other things," he explained.

And those studies did find that moderate amounts of chocolate do seem to lower blood pressure.

"The beneficial effects on blood pressure are likely an important part of the mechanisms of what we're observing," said Mittleman, who is director of the Cardiovascular Epidemiology Research Unit at Beth Israel Deaconess Medical Center at Harvard Medical School in Boston.

The study authors studied the chocolate-eating habits of 31,823 Swedish women, aged 48 to 83, reported over a period of nine years.

Women who ate one to three servings of chocolate (20 to 30 grams) a month had a 32% reduced risk of heart failure, compared to women who did not eat the sweet regularly. More chocolate than that (one to two servings a week), and the benefit disappeared, while much more than that (three to six servings a week), and the risk actually increased by 23%.

"Chocolate is still very calorie-dense, and there's fat and sugar that comes along with it, so moderation is a very important part of the story," Mittleman said.

Chocolate in Sweden is held to different quality standards than in the United States, but there are still characteristics one should look for when choosing chocolate, Mittleman said.

The chocolate measured in this study was mostly high-quality dark chocolate without a lot of added sugar, though it was commercially available, he said.

And the higher the cocoa content, the better. The cocoa content of the chocolate consumed by the women in this study was about 30% whereas, in the United States, dark chocolate is only required to contain 15% cocoa solids.

And 20 to 30 grams would be about half-to-two-thirds of an average American candy bar, Mittleman said.

The heart benefit of dark chocolate could be the result of any number of factors, including more flavanoids, or antioxidants, that can smooth heart function.

Mittleman said there's no reason that the benefits of chocolate wouldn't extend to men as well, but this still needs to be confirmed.

Linda Van Horn, immediate past chair of the American Heart Association's Nutrition Committee and professor in the Department of Preventive Medicine at Northwestern University's Feinberg School of Medicine in Chicago, said people shouldn't misinterpret the study findings as a carte blanche to satisfy their sweet tooth.

"This is not an 'eat all you want' take-home message, rather it's that eating a little dark chocolate can be healthful, as long as other adverse behaviors do not occur, such as weight gain or excessive intake of non-nutrient dense 'empty' calories," she said in a news release issued by the American Heart Association.

Interestingly, an Australian study released last week found that patients would actually prefer taking a pill than chocolate when it comes to controlling blood pressure.

Green leafy veg 'may cut diabetes risk'

A diet rich in green leafy vegetables may reduce the risk of developing diabetes, UK research says.

In an analysis of six studies into fruit and vegetable intake, only food including spinach and cabbage was found to have a significant positive effect.

A portion and a half a day was found to cut type 2 diabetes risk by 14%, the British Medical Journal (BMJ) reports.

But experts urged people to continue to aim for five portions of fruit and vegetables a day.

Continue reading the main story

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This study suggests that green leafy vegetables seem to be particularly important in terms of preventing diabetes”
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Professor Melanie Davies

University of Leicester
The researchers from Leicester University reviewed data from the studies of 220,000 adults in total.

They found that eating more fruit and vegetables in general was not strongly linked with a smaller chance of developing type 2 diabetes but "there was a general trend in that direction".

Yet when it came to green leafy vegetables, which the researchers said also includes broccoli and cauliflower, the risk reduction was significant.

The team calculated that a daily dose of 106g reduced the risk of diabetes by 14% - a UK "portion" is classed as 80g.

It is not clear why green leafy vegetables may have a protective effect but one reason may be they are high in antioxidants, such as vitamin C and another theory is that they contain high levels of magnesium.

Study leader Professor Melanie Davies, professor of diabetic medicine at the University of Leicester, said the message to eat five portions of fruit and vegetables a day remains an important one.

But she added: "People like very specific health messages.

"We know that intake of fruit and vegetables is important, but this study suggests that green leafy vegetables seem to be particularly important in terms of preventing diabetes."

The team are now planning a study in people at high risk of developing the condition to see if increasing their intake of vegetables like spinach and kale can help to reduce their chances of being diagnosed with diabetes.

Fruit and veg

In 2008/09, the National Diet Nutrition Survey showed that, although fruit and vegetable intake has risen over the past decade, only a third of men and women eat the recommended five-a-day.

In an accompanying editorial in the BMJ, Professor Jim Mann from the University of Otago in New Zealand, stressed that the message of increasing overall fruit and vegetable intake must not be lost "in a plethora of magic bullets," even though green leafy vegetables clearly can be included as one of the daily portions.

Dr Iain Frame, director of research at Diabetes UK said: "We already know that the health benefits of eating vegetables are far-reaching but this is the first time that there has been a suggested link specifically between green leafy vegetables and a reduced risk of developing type 2 diabetes."

But he warned the evidence was limited and it was too early to isolate green leafy vegetables and present them alone as a method to cut the chances of developing the condition.

"We would be concerned if focusing on certain foods detracted from the advice to eat five portions of fruits and vegetables a day, which has benefits in terms of reducing heart disease, stroke, some cancers and obesity as well as type 2 diabetes."

Diabetes UK is currently funding research into whether fermentable carbohydrates found in foods such as asparagus, garlic, chicory and Jerusalem artichokes could help weight loss and prevent Type 2 diabetes.