Huifen Wang, a public health specialist at Minnesota University, presented the research at an American Heart Association meeting about high blood pressure.

Rick Miller, a member of the British Dietetic Association, said calcium had “a plethora of effects on the body, including a hypo-tensive effect, meaning it helps to lower blood pressure.”

He explained, “Calcium is needed in muscle tissue, including blood vessel walls, and if there isn’t enough, they are not going to operate properly. In effect the calcium helps keep vessels supple.”

Calcium from dairy products like yogurt and milk was particularly good for this, he said, but taking too much calcium in pill form could have the opposite effect, he cautioned.

Studies indicate it can then be deposited on artery walls, leading to hardening of the arteries.

Miller said were also suggestions that the "friendly" bacteria in yogurt could help lower blood pressure, although these were not conclusive.

Professor Gareth Beevers, a trustee of the Blood Pressure Association, said other studies had shown yogurt to have a "small effect" on lowering blood pressure, but he said it should not be considered a way of counteracting it in people who already had hypertension.

"I would regard it as part of a healthy lifestyle, even if personally I can't stand the stuff," he said.