A diet rich in fibre can cut the risk of early death by up to a third, a study published in The Lancet suggests.

The analysis, which tracked dietary habits for nearly 40 years found that those who ate plenty of foods like fruit and vegetables, wholemeal bread and pasta, and high fibre breakfast cereals, had far lower rates of major diseases.

Overall, those eating such foods saw their risk of early death reduced by up to 30 per cent, the study found. High intake appeared to reduce incidence of heart disease, cancer, stroke, type two diabetes by up to 24 per cent.

And it was associated with lower body weight and cholesterol levels, which experts said was likely to contribute to the improvements in longevity.

Health officials advise eating around 30 grams of fibre daily, which can be achieved by eating five fruit and vegetables, a high fibre cereal, two slices of wholemeal bread, a baked potato and a portion of wholewheat pasta.

The analysis examined 185 observational studies, covering 135 million person years, and 58 clinical trials involving almost 5,000 adults.