Apples and onions have been shown to be beneficial in preventing pancreatic cancer, according to new research.
The study into flavanols quercetin, kaempferol and myricetin revealed that people who eat foods rich in them have a lower risk of developing the disease.
Smokers particularly were found to benefit from increased amounts of the flavanols in their diet and quercetin was shown to be particularly effective.
Researchers from Germany and the universities of Hawaii Southern California published their findings in an October issue of the American Journal of Epidemiology.
The Multiethnic Cohort Study is the first of its kind and involved monitoring 183,518 participants over an eight-year period.
It noted: "Unlike many of the dietary components, flavonols are concentrated in specific foods rather than in broader food groups, for example, in apples rather than in all fruit."
In addition it recorded that women had the highest intake of total flavonols and 70 per cent of the flavonol intake came from quercetin, linked to apple and onion consumption.
Cancer Research UK said that cancer risk can be reduced by a healthy diet that includes fresh fruit and vegetables.