PubMed2005
In Denmark it is recommended to eat 600 g of fruit and vegetables daily. This recommendation has to a large extent been derived from the demonstrated inverse association with the risk of certain major cancer diseases, while the focus with respect to prevention of ischemic heart disease (IHD) has been directed primarily towards a reduced intake of ''hard'' fats. This systematic review includes prospective studies which have examined the association between the intake of fruit and vegetables, as well as specific fruits and vegetables (e.g., nuts and pulses, which are considered to be fruits and vegetables in the Danish recommendations), and the risk of developing IHD. Only one controlled intervention study has been performed. This study came out with a negative result because the advice to increase intake was unsuccessful. In the eight published cohort studies, the overall finding was that the risk of developing IHD was reduced, in the scientifically well-conducted studies, by about 20%. Studies have generally found a dose-response effect, from low intakes to high intakes, up to about 800 g daily. Large cohort studies have shown convincing evidence that increased intake of nuts reduces the risk of IHD. With respect to other groups of fruits and vegetables, there is good but not sufficient scientific evidence that particularly pulses, but also the group of carotenoid-rich fruit and vegetables (such as tomatoes, leafy green vegetables, carrots, broccoli, Brussels sprouts and many berries and fruits), reduces risk. In contrast, it is not possible to single out specific substances in fruit and vegetables as being beneficial. Based on the studies, it seems reasonable to recommend an increased intake of a mix of fruits and vegetables to reduce the risk of IHD. The maximum beneficial amount seems to be about 800 g per day.