Back in February, researchers at Washington State University in Spokane found that green tea could potentially help combat the joint pain, inflammation and tissue damage caused by rheumatoid arthritis (RA). Now new research conducted by a team at Kyoto University shows green tea could prevent a deadly condition in the body's main artery.
Lots, it turns out — even when you take away all the unproven claims that internet snake-oil peddlers will have you believe. Green tea has been shown to improve blood flow and lower cholesterol. It seems to help regulate blood sugar in people who have diabetes. And, when combined with exercise and a healthy, balanced diet, green tea may also help prevent a range of heart-related issues, from high blood pressure to congestive heart failure.
Given green tea's anti-inflammatory properties and its potential benefit for patients with heart-related conditions, it's logical to see why the Kyoto University team took a closer look at its effect on abdominal aortic aneurysm — a condition in which the main artery becomes overstretched and bloated.
The aorta is the body's main supplier of blood, explains the Mayo Clinic. It's about as thick as a garden hose and runs from your heart through the center of your chest and abdomen. Aneurysms occur when the walls of an artery weaken and cause an excessive localized enlargement of the artery.
In the case of abdominal aortic aneurysm, the lower part of the aorta becomes enlarged. Without treatment, they can rupture and lead to death 50% of the time, points out Kenji Minakata, an author of the Kyoto University study.
"Abdominal aortic aneurysms often go unnoticed because there are no symptoms until they burst," adds Minakata. "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."
The researchers found that abdominal aortic aneurysm developed less frequently in rats that were given polyphenol, a major component of green tea.
"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, protecting the artery from rupture.
"Japanese people have the longest lifespans in the world, and studies show that 80% of the population drink green tea on a daily basis," says co-author Hidetoshi Masumoto. "We believe daily intake of green tea should be considered as a new preventative strategy for abdominal aortic aneurysm."
The focus of future studies will be to investigate optimal doses. In the meantime, don't overdo it, but consider adding a cup of green tea a day to your diet.