The value of facial attractiveness for encouraging fruit and vegetable consumption: analyses from a randomized controlled trial.

BACKGROUND: An effect of increased fruit and vegetable (FV) consumption on facial attractiveness has been proposed and recommended as a strategy to promote FV intakes, but no studies to date demonstrate a causal link between FV consumption and perceived attractiveness. This study investigated perceptions of attractiveness before and after the supervised consumption of 2, 5 or 8 FV portions/day for 4 weeks in 30 low FV consumers. Potential mechanisms for change via skin colour and perceived skin healthiness were also investigated. METHODS: Faces were photographed at the start and end of the 4 week intervention in controlled conditions. Seventy-three independent individuals subsequently rated all 60 photographs in a randomized order, for facial attractiveness, facial skin yellowness, redness, healthiness, clarity, and symmetry. RESULTS: Using clustered multiple regression, FV consumption over the previous 4 weeks had no direct effect on attractiveness, but, for female faces, some evidence was found for an indirect impact, via linear and non-linear changes in skin yellowness. Effect sizes, however, were small. No association between FV consumption and skin healthiness was found, but skin healthiness was associated with facial attractiveness. CONCLUSIONS: Controlled and objectively measured increases in FV consumption for 4 weeks resulted indirectly in increased attractiveness in females via increases in skin yellowness, but effects are small and gradually taper as FV consumption increases. Based on the effect sizes from this study, we are hesitant to recommend the use of facial attractiveness to encourage increased FV consumption. TRIAL REGISTRATION: Clinical trial Registration Number NCT01591057 ( www.clinicaltrials.gov ). Registered: 27th April, 2012.

Combining vitamin C and carotenoid biomarkers better predicts fruit and vegetable intake than individual biomarkers in dietary intervention studies.

PURPOSE: The aim of this study was to determine whether combining potential biomarkers of fruit and vegetables is better at predicting FV intake within FV intervention studies than single biomarkers. DESIGN: Data from a tightly controlled randomised FV intervention study (BIOFAV; all food provided and two meals/day on weekdays consumed under supervision) were used. A total of 30 participants were randomised to either 2, 5 or 8 portions FV/day for 4 weeks, and blood samples were collected at baseline and 4 weeks for plasma vitamin C and serum carotenoid analysis. The combined biomarker approach was also tested in three further FV intervention studies conducted by the same research team, with less strict dietary control (FV provided and no supervised meals). RESULTS: The combined model containing all carotenoids and vitamin C was a better fit than either the vitamin C only (P < 0.001) model or the lutein only (P = 0.006) model in the BIOFAV study. The C-statistic was slightly lower in the lutein only model (0.85) and in the model based upon factor analysis (0.88), and much lower in the vitamin C model (0.68) compared with the full model (0.95). Results for the other studies were similar, although the differences between the models were less marked. CONCLUSIONS: Although there was some variation between studies, which may relate to the level of dietary control or participant characteristics, a combined biomarker approach to assess overall FV consumption may more accurately predict FV intake within intervention studies than the use of a single biomarker. The generalisability of these findings to other populations and study designs remains to be tested. Clinical trial Registration Number NCT01591057 ( www.clinicaltrials.gov ).

Increasing Fruit and Vegetable Intake Has No Dose-Response Effect on Conventional Cardiovascular Risk Factors in Overweight Adults at High Risk of Developing Cardiovascular Disease.

BACKGROUND: Improving diet and lifestyle is important for prevention of cardiovascular disease (CVD). Observational evidence suggests that increasing fruit and vegetable (FV) consumption may lower CVD risk, largely through modulation of established risk factors, but intervention data are required to fully elucidate the mechanisms by which FVs exert benefits on vascular health. OBJECTIVE: The aim of this study was to examine the dose-response effect of FV intake on cardiovascular risk factors in adults at high CVD risk. METHODS: This was a randomized controlled parallel group study involving overweight adults (BMI: >27 and ≤35 kg/m(2)) with a habitually low FV intake (≤160 g/d) and a high total risk of developing CVD (estimated ≥20% over 10 y). After a 4-wk run-in period where FV intake was limited to <2 portions/d (<160 g/d), 92 eligible participants were randomly assigned to 1 of 3 groups: to consume either 2, 4, or 7 portions (equivalent to 160 g, 320 g, or 560 g, respectively) of FVs daily for 12 consecutive weeks. Fasting venous blood samples were collected at baseline (week 4) and post-intervention (week 16) for analysis of lipid fractions and high-sensitivity C-reactive protein (hsCRP) concentrations. Compliance with the FV intervention was determined with use of self-reported FV intake and biomarkers of micronutrient status. Ambulatory blood pressure and body composition were also measured pre- and post-intervention. RESULTS: A total of 89 participants completed the study and body composition remained stable throughout the intervention period. Despite good compliance with the intervention, no significant difference was found between the FV groups for change in measures of ambulatory blood pressure, plasma lipids, or hsCRP concentrations. CONCLUSIONS: There was no evidence of a dose-response effect of FV intake on conventional CVD risk factors measured in overweight adults at high CVD risk. This trial was registered at clinicaltrials.gov as NCT00874341.

Postprandial plasma betaine and other methyl donor-related responses after consumption of minimally processed wheat bran or wheat aleurone, or wheat aleurone incorporated into bread.

The bran and particularly the aleurone fraction of wheat are high in betaine and other physiological methyl donors, which may exert beneficial physiological effects. We conducted two randomised, controlled, cross-over postprandial studies to assess and compare plasma betaine and other methyl donor-related responses following the consumption of minimally processed bran and aleurone fractions (study A) and aleurone bread (study B). For both studies, standard pharmacokinetic parameters were derived for betaine, choline, folate, dimethylglycine (DMG), total homocysteine and methionine from plasma samples taken at 0, 0·5, 1, 2 and 3 h. In study A (n 14), plasma betaine concentrations were significantly and substantially elevated from 0·5 to 3 h following the consumption of both bran and aleurone compared with the control; however, aleurone gave significantly higher responses than bran. Small, but significant, increases were also observed in DMG measures; however, no significant responses were observed in other analytes. In study B (n 13), plasma betaine concentrations were significantly and substantially higher following consumption of the aleurone bread compared with the control bread; small, but significant, increases were also observed in DMG and folate measures in response to consumption of the aleurone bread; however, no significant responses were observed in other analytes. Peak plasma betaine concentrations, which were 1·7-1·8 times the baseline levels, were attained earlier following the consumption of minimally processed aleurone compared with the aleurone bread (time taken to reach peak concentration 1·2 v. 2·1 h). These results showed that the consumption of minimally processed wheat bran, and particularly the aleurone fraction, yielded substantial postprandial increases in plasma betaine concentrations. Furthermore, these effects appear to be maintained when aleurone was incorporated into bread.

Dose-response effect of fruit and vegetables on insulin resistance in people at high risk of cardiovascular disease: a randomized controlled trial.

OBJECTIVE: The purpose of this randomized controlled trial was to investigate the dose-response effect of fruit and vegetable (F&V) intake on insulin resistance (IR) in people who are overweight and at high risk of cardiovascular disease (CVD). RESEARCH DESIGN AND METHODS: A total of 105 participants (mean age 56 years) followed a 4-week washout diet (one to two portions of F&Vs per day). Ninety-two participants completed the washout and were randomized to receive one to two, four, or seven portions of F&Vs per day for 12 weeks. IR was assessed at the start and end of this 12-week period by the two-step euglycemic-hyperinsulinemic clamp. Compliance was monitored using a combination of 4-day food diaries and plasma biomarkers of F&V intake. RESULTS: A total of 89 participants completed the study. Participants attained self-reported F&V intakes of 1.8, 3.8, and 7.0 portions per day (P < 0.001) per group. There was a significant linear increase in serum lutein status across the groups, indicating good compliance (P < 0.001), and body weight was maintained (P = 0.77). No significant difference was found between groups in terms of a change in measures of whole-body, peripheral, or hepatic IR or adiponectin multimers. CONCLUSIONS: Increased consumption of F&Vs, as advocated in public-health advice, has no effect on IR in overweight individuals who are at high risk of CVD when body weight is maintained. Recent evidence from systematic reviews indicates that particular classes or types of F&Vs may have particular antidiabetic properties; hence, it is possible that benefits may only be observed in response to a more specific fruit or vegetable intervention.

Evaluation of the effect of wheat aleurone-rich foods on markers of antioxidant status, inflammation and endothelial function in apparently healthy men and women.

Observational data show an inverse association between the consumption of whole-grain foods, and inflammation and related diseases. Although the underlying mechanisms are unclear, whole grains, and in particular the aleurone layer, contain a wide range of components with putative antioxidant and anti-inflammatory effects. We evaluated the effects of a diet high in wheat aleurone on plasma antioxidants status, markers of inflammation and endothelial function. In this parallel, participant-blinded intervention, seventy-nine healthy, older, overweight participants (45-65 years, BMI>25 kg/m²) incorporated either aleurone-rich cereal products (27 g aleurone/d), or control products balanced for fibre and macronutrients, into their habitual diets for 4 weeks. Fasting blood samples were taken at baseline and on day 29. Results showed that, compared to control, consumption of aleurone-rich products provided substantial amounts of micronutrients and phytochemicals which may function as antioxidants. Additionally, incorporating these products into a habitual diet resulted in significantly lower plasma concentrations of the inflammatory marker, C-reactive protein (P = 0·035), which is an independent risk factor for CVD. However, no changes were observed in other markers of inflammation, antioxidant status or endothelial function. These results provide a possible mechanism underlying the beneficial effects of longer-term whole-grain intake. However, it is unclear whether this effect is owing to a specific component, or a combination of components in wheat aleurone.

Consumption of wheat aleurone-rich foods increases fasting plasma betaine and modestly decreases fasting homocysteine and LDL-cholesterol in adults.

There is strong evidence that whole-grain foods protect against heart disease. Although underlying mechanisms and components are unclear, betaine, found at high levels in wheat aleurone, may play a role. We evaluated the effects of a diet high in wheat aleurone on plasma betaine and related measures. In a parallel, single-blinded intervention study, 79 healthy participants (aged 45-65 y, BMI ≥ 25 kg/m(2)) incorporated either aleurone-rich cereal products (27 g/d aleurone) or control products balanced for fiber and macronutrients into their habitual diets for 4 wk. Fasting blood samples were taken at baseline and postintervention (4 wk) from participants. Compared with the control, the aleurone products provided an additional 279 mg/d betaine and resulted in higher plasma betaine (P < 0.001; intervention effect size: 5.2 µmol/L) and lower plasma total homocysteine (tHcy) (P = 0.010; -0.7 µmol/L). Plasma dimethylglycine and methionine, which are products of betaine-mediated homocysteine remethylation, were also higher (P < 0.001; P = 0.027) relative to control. There were no significant effects on plasma choline or B vitamins (folate, riboflavin, and vitamin B-6). However, LDL cholesterol was lower than in the control group (P = 0.037). We conclude that incorporating aleurone-rich products into the habitual diet for 4 wk significantly increases plasma betaine concentrations and lowers tHcy, which is attributable to enhanced betaine-homocysteine methyltransferase-mediated remethylation of homocysteine. Although this supports a role for betaine in the protective effects of whole grains, concomitant decreases in LDL suggest more than one component or mechanism may be responsible.