The fruit study, published on thebmj.com, examined the association between fruit and vegetable intake and risk of premature deaths.
Researchers from China and the US analysed 16 studies involving more than 830,000 participants - 56,000 of whom died during the follow-up period.
Higher consumption of fruit and vegetables was significantly associated with a lower risk of death from all causes, particularly from cardiovascular disease.
They found the average risk of death from all causes was reduced by about 5% for each additional daily serving of fruit and vegetables.
But once a person had consumed five portions, there was no additional benefit noted for extra portions.