The old English proverb "an apple a day keeps the doctor away" is still a useful public health advice, according to Oxford University researchers.

According to a study published in the British Medicine Journal, researchers said prescribing an apple a day to all adults aged 50 and over in Britain would prevent around 8,500 deaths from heart attacks and strokes every year.

The figure is similar to that of a similar study in which researchers prescribed statins, the modern cholesterol-lowering heart drugs, to non-users and estimated that the drug could reduce 9,400 deaths.

"It just shows how effective small changes in diet can be, and that both drugs and healthier living can make a real difference in preventing heart disease and stroke," lead researcher Adam Briggs said.

The researchers also stressed that, no-one currently taking statins because they are at high risk of heart disease should stop, although they really should eat more fruits.