WHO recommends consumption of at least five portions of fruit and vegetables per day (1) . Evidence suggests high intake of fruit and vegetables is associated with decreased risk of CVD and certain cancers (2,3) . It is postulated that increasing fruit and vegetable consumption has direct health benefits; however, increased consumption may also indirectly improve health by changing the overall balance of the diet, as extra fruit and vegetables may be substituted for less healthy foods. It is, therefore, unclear whether the health benefits of fruit and vegetables are directly related to the intrinsic properties of these foods or to their impact on overall diet profile. The aim of the present systematic review and meta-analysis was to determine the effect of increased consumption of fruit and vegetables on overall diet.Six databases were searched from earliest record until April 2010. Search criteria included fruit and vegetable, randomised controlled trials, adult trials and those published in the English language. A total of 6413 publications were returned on initial search and titles and abstracts reviewed, 173 publications were then retrieved for closer analysis. Of these, twelve papers were included in the final systematic review and seven papers contained sufficient data to form the meta-analysis.For the purposes of the systematic review, seven of twelve studies reporting on energy in kilojoules and all six studies reporting on protein, showed no significant change when fruit and vegetable consumption was increased. Five of ten studies reporting on total fat, and three of four studies reporting on saturated fat showed significant decreases in intakes, with the remainder reporting no significant change. The two studies measuring monounsaturated fat intake both showed significant decreases. On the other hand, five of seven studies reporting on carbohydrate intake and six of eight studies reporting on fibre intake showed significant increases, while it was also found that the majority of micronutrients (including the carotenoids, lutein, lycopene and vitamins C and E) showed significant increases when fruit and vegetable intake was increased.For the meta-analysis, having pooled results from seven studies, there was no evidence of a difference in energy in kilojoules between the intervention (i.e. fruit and vegetable group) and control group (mean difference = 37.6 kJ [95 % CI -80, 97]; P = 0.85). In five studies, on average there was a significant decrease in fat, reported as % energy, in the intervention group compared with the control group (mean difference = -4 % [95 % CI, -5, -3]; P £ 0.00001); while in three studies, though not significant, there was also a reduction in fat reported in grams in the intervention group compared with the control (mean difference = -9 g [95 % CI -20, 2]; P = 0.10). Overall, in six studies, on average, fibre in grams was higher in the intervention group compared with the control group (mean difference = 5.36 g [95% CI 4, 7]; P £ 0.00001). There was little evidence of heterogene...
Fruit and vegetable (FV) intake is associated with reduced risk of a number of non-communicable diseases. Research tends to focus on antioxidants, flavonoids and polyphenols contained in FV as the main beneficial components to health; however, increasing FV may also alter overall diet profile. Extra FV may be substituted for foods thought to be less healthy, therefore altering the overall macronutrient and/or micronutrient content in the diet. This analysis merged dietary data from four intervention studies in participants with varying health conditions and examined the effect of increased FV consumption on diet profile. Dietary intake was assessed by either diet diaries or diet histories used in four FV randomised intervention studies. All food and drink intake recorded was analysed using WISP version 3.0, and FV portions were manually counted using household measures. Regression analysis revealed significant increases in intakes of energy (172 kJ (+41 kcal)), carbohydrate (+3·9 g/4184 kJ (1000 kcal)), total sugars (+6·0 g/4184 kJ (1000 kcal)) and fibre (+0·8 g/4184 kJ (1000 kcal)) and significant decreases in intakes of total fat (-1·4 g/4184 kJ (1000 kcal)), SFA (-0·6 g/4184 kJ (1000 kcal)), MUFA (-0·6 g/4184 kJ (1000 kcal)), PUFA (-0·1 g/4184 kJ (1000 kcal)) and starch (-2·1 g/4184 kJ (1000 kcal)) per one portion increase in FV. Significant percentage increases were also observed in vitamin C (+24 %) and -carotene (+20 %) intake, per one portion increase in FV. In conclusion, pooled analysis of four FV intervention studies, that used similar approaches to achieving dietary change, in participants with varying health conditions, demonstrated an increase in energy, total carbohydrate, sugars and fibre intake, and a decrease in fat intake alongside an expected increase in micronutrient intake.
Research predominantly focuses on high levels of antioxidants, flavonoids and polyphenols contained in fruit and vegetables (FVs) as the beneficial components to health; however, increasing FV may also alter overall diet profile. Furthermore FV variety may have an effect on disease risk (1) , yet it is not known whether increasing FV quantity also necessarily leads to an increase in variety. Therefore the aims of this research were, firstly to determine the effect of increasing FV intake on overall diet profile and, secondly, to examine how participants asked to increase FV intake achieved this.Data was collected as part of an 8-week randomised controlled trial of diabetic patients, where FV intake increased to ‡ 6 portions/ day or participants followed a low FV diet ( £ 1 portion/day), after a 4 week run-in period. Subjects collected 7-day food diaries, which were analysed using WISP-DESv3.0. Daily portion counts were manually counted using household measures established by the Department of Health (2) . Between group analysis of changes in macronutrient intakes (see table below), revealed significant differences in the majority of nutrients, but not energy intake, when FV intake increased. Between group analysis of changes in micronutrient intakes revealed significant differences in intakes of vitamins C and E, carotene, magnesium, potassium, and folate. The lack of difference in change in energy intake between the groups suggests there was substitution of FVs for other potentially less healthy foods. Peas, baked beans and carrots were the most common vegetable choices, whilst bananas, apples and tomatoes were the most common fruit choices. The number of different FV choices made at week 8, in the 1 and 6 portion groups respectively, were fruit: 24, 35, and vegetables: 26, 44. Therefore, individuals chose a greater variety of FVs as opposed to just larger quantities of the same FV when asked to increase intakes. Breakfast was the most popular time for fruit intake, and lunch and dinner for vegetable intake.In conclusion, when diabetic participants increased FV intake, an improvement was observed in overall diet profile, with an increase in the variety of FV consumed, no significant difference in energy, decreases in saturated and monounsaturated fats and increases in carbohydrates, total sugars, dietary fibre and a number of micronutrients.
An increased intake of fruit and vegetables has been associated with decreased risk of cardiovascular disease (CVD). However, it is currently unclear as to whether particular fruits and vegetables convey more benefit than others, and if the form in which a particular fruit or vegetable is delivered, for example, depending on polyphenol content or the degree of processing, affects potential health benefits. The aim of this study was to conduct a pilot randomised placebo-controlled trial (RCT) with the ultimate aim of assessing if different apple products differentially affect CVD risk factors. The RCT was conducted in those at elevated risk of CVD. Participants were randomised to receive high polyphenol apples, low polyphenol apples, capsules containing apple extract, dried apple pieces or placebo capsules to take for four weeks. A range of risk factors and biomarkers associated with CVD were measured before and after the intervention period. A total of 55 participants were randomised and completed the study. Change in hip circumference was significantly different across the groups after 4 weeks (P=0.02) Change in fibre intake was also statistically significant between groups, with those consuming high polyphenol apples having a higher intake than those on the apple extract (P=0.01). There was a significant within-group change in fasting oxidised LDL in the apple extract group (P=0.008). A significant difference in change in volume-corrected epicatechin was observed (P=0.03), with those on apple extract having higher levels than those on placebo capsule (P=0.002) or low polyphenol apples (P=0.01) Overall, interventions were generally acceptable to participants. Apple products appeared to have a positive effect on some risk factors for CVD in this pilot study, which indicated a definitive RCT is feasible. Further adequately powered studies need to be conducted to definitively test these findings.
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