常喝綠茶可預防心臟病

A few cups of green tea each day may help prevent heart disease, Greek researchers said on Wednesday.

A study published in the European Journal of Cardiovascular Prevention and Rehabilitation showed further evidence of the potential health benefits from a brew already linked to a reduced risk of a range of cancers and other conditions.

The study showed that green tea improves blood flow and the ability of arteries to relax, said Charalambos Vlachopoulos, a cardiologist at the Athens Medical School in Greece who worked on the study.

Other studies have shown that black tea also has benefits for cardiovascular health.

The Greek team said they believed green tea might be even better because it had higher quantities of beneficial compounds called flavonoids —some of which are lost in the oxidation process that black tea undergoes.

Flavonoids are also found in cocoa, tomatoes and grapes.

“A couple of cups a day would probably be a good dose for people,” Vlachopoulos said. “This is the first study to show these effects for green tea.”

The researchers gave 14 healthy volunteers either green tea, diluted caffeine or hot water and then measured the function of endothelial cells lining the circulatory system.

These cells help relax arteries and ease blood flow.

“What is important is these effects are evident fairly rapidly, within 30 minutes,” Vlachopoulos said. The measurements taken 30, 90 and 120 minutes following consumption showed an almost immediate benefit among people who had drunk green tea, he said.

While the researchers looked only at a short-term impact, Vlachopolous said the teams studies suggest the protection is long lasting.

“Green tea is consumed less in the Western world than black tea, but it could be more beneficial because of the way it seems to improve (circulatory) function,” he said.

希臘研究人員于本周三稱，每天喝幾杯綠茶有助于預防心臟病。

在《歐洲心血管病預防與恢復期刊》上發表的一項研究顯示，有更多的證據已證明綠茶具有潛在的保健功效，能夠降低患癌癥及其他疾病的風險。

從事該研究的希臘雅典醫學院心臟病學家卡拉蘭波斯?維拉科珀羅斯說，研究發現綠茶能夠促進血液流動，并能增強動脈疏通能力。

此前已有研究表明紅茶對心血管健康也有好處。

希臘的這一研究小組稱，他們認為綠茶的心血管保健功效可能會更強，因為綠茶中所含的一種名叫“類黃酮”的有益物質較多，而這種物質在紅茶氧化過程中會部分流失。

可可、西紅柿和葡萄中也含有類黃酮。

維拉科珀羅斯說：“每天喝幾杯綠茶可能最益于健康。這是第一個表明綠茶具有心血管保健功效的研究。”

研究人員讓14名身體健康的志愿者分別飲用綠茶、稀釋的咖啡和熱水，然后對他們的循環系統內皮細胞的機能進行檢測。

內皮細胞有助于疏通動脈，促進血液循環。

維拉科珀羅斯說：“關鍵是效果很快就顯現出來了，30分鐘內就見效。”

他說，對喝了綠茶的研究對象在飲茶30分鐘、90分鐘及120分鐘后的檢測結果顯示，綠茶的功效可謂“立竿見影”。

盡管研究人員只探究了綠茶的短期功效，但維拉科珀羅斯稱，他們的研究表明，這種保護功效是長期的。

他說：“在西方國家，人們喝紅茶多于綠茶。但由于綠茶具有促進血液循環的功能，所以喝綠茶可能更有益于健康。”