Scientists examined the eating habits of 257,500 people from Europe, Japan and the United States, who took part in eight separate studies.

They found that those who ate more than five portions of fruit and vegetables -- the amount recommended by the UK government -- were 26 percent less likely to have a stroke than those who ate fewer than three portions.

Eating three to five portions resulted in an 11 percent reduction.

Common Cause of Disability

Stroke is the third-biggest cause of death and the most common cause of disability in most developed countries.

Previous research has shown that increased consumption of fruit and vegetables is related to a reduced risk of stroke, but the extent of the association has been uncertain until now.

The research, reported by The Lancet medical journal yesterday, was carried out by a team led by Dr. Feng He, of London University, who said that the findings showed the tangible benefits that could be achieved if people changed their eating habits.

"Our analysis demonstrates that a higher intake of fruit and vegetables is associated with a lower risk of stroke," he said. "The average intake in most developed countries is about three servings per day and current recommendations encourage five or more servings per day.

"Our results provide strong support for these recommendations. If these goals were achieved, stroke morbidity and mortality would be greatly reduced.

"Such diet modifications would also reduce other cardiovascular disease and some cancers."

Blood-Pressure Lowering Effect

In Scotland, the mortality rate from strokes fell recently from 79.1 per 100,000 people in 2003 to 74.2 in 2004, amid signs the public is starting to get the message about eating more fruit and vegetables.

Strokes are caused by a clot that prevents blood flow to the brain, resulting in damage to cells there -- or death.

Coronary heart disease remains the biggest killer, responsible for the deaths of about twice as many people.

The report said the protective powers of fruit and vegetables against stroke had a strong biological basis. "[They] are rich sources of potassium, folate, fiber and antioxidants [such as] vitamin C, betacarotene and flavinoids," it said.

"Since raised blood pressure is the major cause of stroke, the blood-pressure lowering effect of potassium could be one of the major mechanisms contributing to a reduced risk of stroke with an increased fruit and vegetable intake."

Combat Junk Food Diets

Dr. He admitted that the study did have some limitations, because people who eat a better diet also tend to smoke less, consume less salt and saturated fat and take more exercise.

Dr. Lynn Steffen, of Minnesota University's school of public health in the US, said age-old wisdom that children should "eat their greens" had been proved right. "Your parents were smart when they told you to eat all of your vegetables and encouraged you to eat your fruit," she said in an accompanying article for the Lancet. "But they probably did not know that eating more fruit and vegetables would lower the risk of stroke."

She said more should be done to encourage children not to exist on a diet of junk-food.

"Low intake of fruit and vegetables is a major modifiable risk factor contributing to the burden of ill-health. Because food habits develop in childhood, we must protect young people from developing chronic disease early in life.

"Therefore, partnerships must be formed between public-health agencies, state and local industry and the media to promote healthy food choices."