Dark chocolate may help reduce blood

Natural yoghurt beats bad breath
Dark chocolate -- but not white chocolate - may help reduce blood pressure and boost the body's ability to metabolize sugar from food, according to the results of a small study.
Investigators from the University of L'Aquila in Italy found that after eating only 100 grams, or 3.5 ounces, of dark chocolate every day for 15 days, 15 healthy people had lower blood pressures and were more sensitive to insulin, an important factor in metabolizing sugar.
In contrast, eating roughly the same amount of white chocolate for the same period of time did not affect either blood pressure or insulin sensitivity.
This is not the first study to demonstrate potential health benefits of dark chocolate, which contains high levels of a kind of antioxidant called flavonoids. Research shows that flavonoids that can help maintain a healthy heart and good circulation and reduce blood clotting, which can lead to heart attacks and stroke.
Dr. Claudio Ferri and co-investigators explained that flavonoids help the body by neutralizing potentially cell-damaging substances known as oxygen-free radicals, which are a normal byproduct of metabolism.
However, despite dark chocolate's apparent benefits, Ferri urges caution when interpreting the results. Dark chocolate contains antioxidants, but also a lot of fat and calories, Ferri said, and people who want to add some chocolate to their diet need to subtract an equivalent amount of calories by cutting back on other foods, to avoid weight gain.
He added that each 100 grams of dark chocolate contains roughly 500 calories.
Other research validates that when it comes to chocolate, type does matter. One study found that eating milk chocolate did little to raise antioxidant levels in the blood, perhaps because milk interferes with the absorption of antioxidants from chocolate.
Another study showed that elderly people with high blood pressure experienced a drop in pressure after eating dark chocolate bars, but not white chocolate, which contains no flavonoids.
Ferri and colleagues asked 7 men and 8 women, all healthy, to eat 100 grams of dark chocolate or 90 grams of white chocolate every day for 15 days. The subjects consumed no chocolate for the next 7 days and then switched to the other chocolate type for 15 days.
"The identification of healthy foods and the understanding of how food components influence normal physiology will help to improve the health of the population," Dr. Cesar G. Fraga of the University of California, Davis, notes in an editorial.

一項小規模研究的結果表明，黑巧克力可能有助於降低血壓、促進人體對食物中的糖分的代謝能力，而白巧克力則沒有這些功能。
義大利拉奎拉大學的調查者們發現，在連續15天每日食用100克或3.5盎司黑巧克力之後，15名健康的受試者的血壓有所降低，而且對胰島素更為敏感--胰島素是促進體內糖分代謝的重要成分。
相比之下，同樣在15天中食用大致相同數量的白巧克力對血壓和胰島素的敏感性並沒有影響。
這已經不是有關黑巧克力可能有益健康的第一項研究。黑巧克力富含一種叫作類黃酮的抗氧化劑，研究表明類黃酮有助於保持心臟的健康和血液迴圈的暢通，並減少可能導致心臟病和中風的血栓。
克勞迪奧·費裏教授與他的合作者們解釋說，類黃酮能抑制對細胞有破壞能力的氧自由基(新陳代謝的副產品)的產生，從而有利於人體健康。
然而，儘管黑巧克力具有以上種種顯而易見的好處，費裏教授在解釋研究結果時還是勸告人們提高警惕，他說，黑巧克力含有抗氧化劑，但也含有大量脂肪和卡路里，因此希望在飲食中添加巧克力的人們需要從其他食物中“扣除”等量的卡路里，以免體重增加。
他補充說，每100克黑巧克力包含大約500卡路里。
其他的研究也證實了不同種類的巧克力確實功效不同。一項研究表明食用牛奶巧克力並不能增加血液中的抗氧化劑，這也許是因為牛奶阻礙了巧克力中的抗氧化劑的吸收。
另一項研究結果表明，患有高血壓的老人在吃了黑巧克力棒後血壓下降，但是不含類黃酮的白巧克力則沒有這個功效。
費裏教授和他的同事們找了七名健康的男性和八名健康的女性，讓他們連續15天每天食用100克黑巧克力或90克白巧克力。受試者們在隨後的七天內沒有吃任何巧克力，然後在接下來的15天內轉而吃另一種巧克力(白巧克力或黑巧克力)。
“對健康食物的定義以及對食物成分如何影響正常生理功能的理解，將有助於改善人口的健康狀況。”加里佛尼亞大學大衛斯分校的愷撒·G·弗拉革博士在一篇評論中寫道。