By Patricia Reaney
London - Eating more than the recommended five portions of fruit and vegetables a day can further reduce the odds of suffering a stroke, researchers said on Friday.
An analysis of eight studies that looked into the impact of fruit and vegetables on stroke showed that the more healthy foods people consumed, the less likely they were to have a stroke, which is a leading cause of disability and death.
"For the first time we have shown a quantitative relationship between fruit and vegetable consumption and stroke," said Professor Graham MacGregor of St George's medical school at the University of London.
"It has been known that fruit and vegetables seem to reduce stroke but it wasn't known how much they did it by," he added in an interview.
In the analysis of research involving more than 257 500 people from Japan, Europe and the United States, the scientists found that people who ate more than five servings of fruit and vegetables a day had a 26 percent reduction in stroke compared to individuals who consumed less than three servings daily.
"It is a very important finding because it really shows that the quantity of fruit and vegetables you should be eating is more than five a day," MacGregor said.
The average fruit and vegetable consumption a day in most developed countries is three to five servings. A serving of vegetables is 77g and 80g for fruit, according to MacGregor and his team.
Strokes are caused by a blockage in an artery leading to the brain or bleeding in or around the brain. About 17 million people die each year of cardiovascular diseases, particularly heart attacks and strokes. High blood pressure, diabetes, smoking, raised cholesterol, obesity and lack of exercise are risk factors.
Fruit and vegetables are full of nutrients such as vitamin C, beta carotene and potassium as well as plant proteins and dietary fiber.
The researchers suspect that potassium is an important factor in preventing stroke.
"We've know that if you give people addition potassium it lowers blood pressure," said MacGregor, who reported the research in The Lancet medical journal.
"By increasing to five servings a day from three you would increase your potassium intake by about 50 percent," he added.
MacGregor said fruit and vegetables also are less calorie-dense, have very little fat and contain anti-oxidants which may also be beneficial.