Secret ingredient in black tea may prevent stroke

A cup of black tea with a piece of dark chocolate each day may help stave off heart disease in older people, a new study has revealed.

Coronary heart disease is the leading cause of death for people aged between 75 and 84 and second for groups over 65 and 85.

An Edith Cowan University's research team followed nearly 900 older women who drank a few cups of black tea each day to observe their risk of arterial calcification.

Arterial calcification is a process where calcium is deposited in major arteries instead of the bones and is associated with higher risks of heart attacks, stroke and dementia.

Women who drank between two to six cups per day were 42 per cent less likely to have a calcium buildup in their arteries, the team found.

"Vascular calcification is a major predictor of heart disease," study lead Ben Parmenter said.

"We've shown that protection against heart disease could be achievable through most people's diets." 

The secret ingredients in black tea that lowered heart disease risk were chemicals called flavonoids.

They're found in diet staples we consume each day, such as green and black tea, nuts, berries, dark chocolate and apples.

Flavonoids are not like vitamins or minerals – we don't need to consume them, but if we do, they appear to provide health benefits, Parmenter said.

"This is the first study that shows a high intake of flavonoids can protect against vascular calcification," he said.

Vascular calcification is considered an early marker of arteriosclerosis, where the buildup of fats and cholesterol causes the major arteries to narrow and block blood flow.

The main contributing factors that can lead to arteriosclerosis are high blood pressure, high cholesterol, an unhealthy diet, lack of exercise and older age.

"We're talking about a very specific disease process," Parmenter said.

"It doesn't have anything to do with your calcium intake.

"Calcium is just being deposited in the wrong place."

The research found that a high intake of flavonoids was also associated with lowered blood pressure and reduced risk of dementia.

Once the body absorbs flavonoids, they signal pathways that provide anti-oxidant and anti-inflammatory mechanisms. 

Parmenter said these pathways might help reduce the progression of calcium buildup in the arteries.

"For people who don't drink tea, there are plenty of other flavonoid-rich foods and beverages," he said.

"Higher non-tea flavonoid intake also helps to protect against calcification of the arteries and reduce your risk of heart disease."

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