Two apples and five carrots a day keep the doctor away: Strategies to increase fruit and vegetable consumption

(See paper by Booth and colleagues, pages 115–120) It would seem that one of the few, if not only, noncontroversial issues in nutrition, is that fruit and vegetables are good for health, and generally the more, the better (with the possible exception of fruit juice and potatoes). Worldwide, dietary guidelines of one sort or another include a message on fruit and vegetables. Such advice may range from a qualitative food-based dietary guideline approach, as commonly seen in developing countries (e.g. Eat plenty of fruits and vegetables every day; South Africa), to a more quantitative approach that defines portion sizes and types, as the case for the American dietary guidelines (‘Two cups of fruit and 21⁄2 cups of vegetables per day are recommended for a 2000-calorie intake’ and ‘. . . select from all five vegetable subgroups (dark green, orange, legumes, starchy vegetables, and other vegetables) several times a week’). The Global Burden of Diseases Project estimated that up to 2.6 million lives per year could potentially be saved if fruit and vegetable consumption was sufficiently increased. International agencies have identified the level of evidence to be convincing for a reduced risk between fruit and non-starchy vegetable intake and cardiovascular disease and probable for a reduced risk for some cancers, diabetes and obesity, as well as for the prevention of several micronutrient deficiencies. The DASH diet demonstrated, unequivocally, that a diet rich in fruit and vegetables significantly reduces systolic and diastolic blood pressure, in both normotensive and hypertensive individuals. The follow-up DASH Sodium study investigated the additional benefits of salt restriction over and above the merits of the DASH diet. The paper of Booth and colleagues (page X) has demonstrated that the WELL diet, which is based on their previous OZDASH diet, resulted in a mean intake of 8.7 serves of fruit and vegetables per day at three months. What makes the findings of Booth et al.’s study even more impressive is that the study group comprised men who were healthy, and had normal blood pressure. In the parent paper to that of Booth et al. more detailed information is provided on the components of the intervention. Participants were assisted by a trained dietitian to set goals for diet ( three goals) and exercise ( one goal) at each visit. The main difference between the control (low fat) diet and the WELL diet was that the WELL diet group was provided with specified targets for fruit, vegetable and dairy intake, and received individual feedback about adherence to these targets. The Booth paper raises four key questions relating to interventions aimed at increasing fruit and vegetable consumption: ‘What targets should we be aiming for?’, ‘What is the most effective type of intervention to change fruit and vegetable behaviour?’, ‘Are changes in fruit and vegetable consumption sustainable in the long term?’ and ‘Can a one-size-fits-all approach be adopted?’.