Drinking green tea can help prevent deadly abdominal aortic aneurysms, a condition in which the body's main artery becomes stretched and bloated. If it eventually ruptures, it is fatal in at least 50 percent of cases.

Researchers at Japan's Kyoto University found that drinking green could prevent the condition. They believe that the beneficial compounds in green tea are polyphenols, a type of antioxidant that fights free radicals and reduces inflammation. The polyphenols also appear to make arteries stronger and more flexible.

"The type of polyphenol found in green tea has recently been shown to regenerate elastin, an essential protein that gives the artery its stretchy, yet sturdy, texture," explains lead author Shuji Setozaki. "Considering that abdominal arterial aneurysms are caused by inflammation and the degradation of elastin components in the arterial wall, we thought drinking green tea may show promise for treatment."

In the study, the team treated rats with enzymes that induce abdominal aortic aneurysm, and found that the condition developed less in rats that drank green tea polyphenol. They also saw less inflammation and more elastin production, which protected the artery from rupture.

"Abdominal aortic aneurysms often go unnoticed because there are no symptoms until they burst," says Kenji Minakata, an author of the study. "If a patient is lucky and bloating is found before rupture, it needs to be treated surgically, such as by transplanting an artificial blood vessel or inserting a stent graft. At the moment there are no pharmacological treatments."

Numerous recent studies have pointed to a long list of health benefits from drinking green tea, including the prevention of cancer, cardiovascular disease, inflammation, and oxidation.

"We believe daily intake of green tea should be considered as a new preventive strategy for abdominal aortic aneurysms," said co-author Hidetoshi Masumoto. "The focus of future studies will be to investigate optimal doses."

Other rich dietary sources of polyphenols include cocoa powder, black elderberries, flaxseed, blueberries, and olives.

More than 3 million cases of abdominal aortic aneurysms occur each year in the United States. They often grow slowly with no symptoms, and occur most often in men over the age of 60. Other factors include high blood pressure and smoking.