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 ).

Carotenoids and health in older people.

As the proportion of older people increases, so will chronic disease incidence and the proportion of the population living with disability. Therefore, new approaches to maintain health for as long as possible in this age group are required. Carotenoids are a group of polyphenolic compounds found predominantly in fruit and vegetables that have been proposed to have anti-inflammatory and antioxidant effects. Such properties may impact on the risk diseases which predominate in older people, and also ageing-related physiological changes. Working out the effect of carotenoid intake versus fruit and vegetable intake is difficult, and the strong correlation between individual carotenoid intakes also complicates any attempt to examine individual carotenoid health effects. Similarly, research to determine whether carotenoids consumed as supplements have similar benefits to increased dietary intake through whole foods, is still required. However, reviewing the recent evidence suggests that carotenoid intake and status are relatively consistently associated with reduced CVD risk, although ß-carotene supplementation does not reduce CVD risk and increases lung cancer risk. Increased lycopene intake may reduce prostate cancer progression, with a potential role for carotenoids at other cancer sites. Lutein and zeaxanthin have a plausible role in the maintenance of eye health, whilst an association between carotenoid intake and cognitive and physical health appears possible, although research is limited to date. Given this accruing evidence base to support a specific role for certain carotenoids and ageing, current dietary advice to consume a diet rich in fruit and vegetables would appear prudent, and efforts maintained to encourage increased intake.