Coffee may help prevent breast cancer in some women, a study suggests.

Two or three cups a day can cut the risk by a third or delay onset by 10 years.

Experts at Lund and Malmo universities in Sweden found it hinders the process by which female sex hormones can cause cancer.

Caffeine in a cuppa is also known to hamper the growth of cancer cells.

But researcher Helena Jernstrom said: "This information needs to be corroborated before we can issue recommendations."