Snacking on half a handful of nuts every day could reduce the chances of dying from diabetes, cancer and heart disease.

Researchers in the Netherlands discovered the health benefits for people who ate around 10g of nuts or peanuts per day.

But it was bad news for lovers of peanut butter - as scientists said salt and trans fatty acids contained in the spread could inhibit the protective effects of peanuts.

Epidemiologist Professor Piet van den Brandt, who led the study at Maastricht University, said the findings were "remarkable".

"A higher intake was not associated with further reduction in mortality risk," he added.

"This was also supported by a meta-analysis of previously published studies together with the Netherlands Cohort Study, in which cancer and respiratory mortality showed this same dose-response pattern."

Researchers said peanuts and tree nuts both contain various vitamins, fibre, antioxidants and compounds that could possibly contribute to the lower death rates.

The reduction in mortality was strongest for respiratory disease, neurodegenerative disease, and diabetes, followed by cancer and cardiovascular diseases in both men and women.

The research was carried out in conjunction with the Netherlands Cohort Study, which started in 1986.

The nut-eating habits of more than 120,000 Dutch men and women between the ages of 55 and 69 were recorded.

It was discovered that regular nut-eaters tended to be younger, more highly educated, to drink more alcohol, eat more fruit and vegetables, more likely to take supplements and to be less hypertensive.

Women who ate nuts were also often leaner, had never smoked and were less likely to report diabetes.

The study is published in the International Journal of Epidemiology.