Britons should eat seven portions of fresh fruit and vegetables a day, according to new research into healthy eating, published on Tuesday. The researchers found that seven or more portions a day can reduce a person's overall risk of death by 42 percent compared to people who manage just one portion. People who eat between five and seven a day have a 36 percent reduced risk of death and those who eat three to five have a 29 percent decreased risk.

It fell to 14 percent for those who eat one to three portions. The study, published in the Journal of Epidemiology and Community Health, showed that fresh vegetables had the strongest effect, followed by salad and then fruit.

The state-run National Health Service currently recommends each person eats five 80-gramme (three-ounce) helpings of fruit and vegetables daily. But researchers at University College London (UCL) found that eating seven portions or more could reduce the risk of dying from cancer by 25 percent and of heart disease by 31 percent compared to people who consume less than one portion of fruit or vegetables a day.

"We all know that eating fruit and vegetables is healthy, but the size of the effect is staggering," said lead author Oyinlola Oyebode of UCL's Department of Epidemiology and Public Health. "The clear message here is that the more fruit and vegetables you eat, the less likely you are to die at any age.

However, the researchers found that eating frozen and canned fruit increased the risk of death by 17 percent compared to those who ate less than a portion a day.