Research - Fruit + Vegetables General
Effectiveness of dietary interventions among adults of retirement age: a systematic review and meta-analysis of randomized controlled trials
Jose Lara, Nicola Hobbs, Paula J Moynihan, Thomas D Meyer, Ashley J Adamson, Linda Errington, Lynn Rochester, Falko F Sniehotta, Martin White and John C Mathers
Background Retirement from work involves significant lifestyle changes and may represent an opportunity to promote healthier eating patterns in later life. However, the effectiveness of dietary interventions during this period has not been evaluated.
Methods We undertook a systematic review of dietary interventions among adults of retirement transition age (54 to 70 years). Twelve electronic databases were searched for randomized controlled trials evaluating the promotion of a healthy dietary pattern, or its constituent food groups, with three or more months of follow-up and reporting intake of specific food groups. Random-effects models were used to determine the pooled effect sizes. Subgroup analysis and meta-regression were used to assess sources of heterogeneity.
Results Out of 9,048 publications identified, 67 publications reporting 24 studies fulfilled inclusion criteria. Twenty-two studies, characterized by predominantly overweight and obese participants, were included in the meta-analysis. Overall, interventions increased fruit and vegetable (F&V) intake by 87.8 g/day (P <0.00001), with similar results in the short-to-medium (that is, 4 to 12 months; 85.6 g/day) and long-term (that is, 12 to 58 months; 87.0 g/day) and for body mass index (BMI) category. Interventions produced slightly higher intakes of fruit (mean 53.7 g/day) than of vegetables (mean 41.6 g/day), and significant increases in fish (7 g/day, P = 0.03) and decreases in meat intake (9 g/day, P <0.00001).
Conclusions Increases in F&V intakes were positively associated with the number of participant intervention contacts. Dietary interventions delivered during the retirement transition are therefore effective, sustainable in the longer term and likely to be of public health significance.
Source + BMC
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Natural plant compound prevents Alzheimer's disease in mice
A chemical that's found in fruits and vegetables from strawberries to cucumbers appears to stop memory loss that accompanies Alzheimer's disease in mice, scientists have discovered. In experiments on mice that normally develop Alzheimer's symptoms less than a year after birth, a daily dose of the compound -- a flavonol called fisetin -- prevented the progressive memory and learning impairments. The drug, however, did not alter the formation of amyloid plaques in the brain, accumulations of proteins which are commonly blamed for Alzheimer's Disease. The new finding suggests a way to treat Alzheimer's symptoms independently of targeting amyloid plaques.
"We had already shown that in normal animals, fisetin can improve memory," says Pamela Maher, a senior staff scientist in Salk's Cellular Neurobiology Laboratory who led the new study. "What we showed here is that it also can have an effect on animals prone to Alzheimer's."
More than a decade ago, Maher discovered that fisetin helps protect neurons in the brain from the effects of aging. She and her colleagues have since -- -in both isolated cell cultures and mouse studies -- -probed how the compound has both antioxidant and anti-inflammatory effects on cells in the brain. Most recently, they found that fisetin turns on a cellular pathway known to be involved in memory.
"What we realized is that fisetin has a number of properties that we thought might be beneficial when it comes to Alzheimer's," says Maher.
So Maher -- -who works with Dave Schubert, the head of the Cellular Neurobiology Lab -- -turned to a strain of mice that have mutations in two genes linked to Alzheimer's disease. The researchers took a subset of these mice and, when they were only three months old, began adding fisetin to their food. As the mice aged, the researchers tested their memory and learning skills with water mazes. By nine months of age, mice that hadn't received fisetin began performing more poorly in the mazes. Mice that had gotten a daily dose of the compound, however, performed as well as normal mice, at both nine months and a year old.
"Even as the disease would have been progressing, the fisetin was able to continue preventing symptoms," Maher says.
In collaboration with scientists at the University of California, San Diego, Maher's team next tested the levels of different molecules in the brains of mice that had received doses of fisetin and those that hadn't. In mice with Alzheimer's symptoms, they found, pathways involved in cellular inflammation were turned on. In the animals that had taken fisetin, those pathways were dampened and anti-inflammatory molecules were present instead. One protein in particular -- -known as p35 -- -was blocked from being cleaved into a shorter version when fisetin was taken. The shortened version of p35 is known to turn on and off many other molecular pathways. The results were published December 17, 2013, in the journal Aging Cell.
Studies on isolated tissue had hinted that fisetin might also decrease the number of amyloid plaques in Alzheimer's affected brains. However, that observation didn't hold up in the mice studies. "Fisetin didn't affect the plaques," says Maher. "It seems to act on other pathways that haven't been seriously investigated in the past as therapeutic targets."
Next, Maher's team hopes to understand more of the molecular details on how fisetin affects memory, including whether there are targets other than p35.
"It may be that compounds like this that have more than one target are most effective at treating Alzheimer's disease," says Maher, "because it's a complex disease where there are a lot of things going wrong."
They also aim to develop new studies to look at how the timing of fisetin doses affect its influence on Alzheimer's.
"The model that we used here was a preventive model," explains Maher. "We started the mice on the drugs before they had any memory loss. But obviously human patients don't go to the doctor until they are already having memory problems." So the next step in moving the discovery toward the clinic, she says, is to test whether fisetin can reverse declines in memory once they have already appeared.
- Antonio Currais, Marguerite Prior, Richard Dargusch, Aaron Armando, Jennifer Ehren, David Schubert, Oswald Quehenberger, Pamela Maher. Modulation of p25 and inflammatory pathways by fisetin maintains cognitive function in Alzheimer's disease transgenic mice. Aging Cell, 2013; DOI: 10.1111/acel.12185
Source : Science Daily
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A Novel Approach for Increasing Fruit Consumption in Children
Anastasia Perikkou, MSc., Anna Gavrieli, PhD, Maria-Matina Kougioufa, Maria Tzirkali, MSc., Mary Yannakoulia, PhD
Despite the well-documented health benefits of fruits and vegetables and the public health campaigns promoting their consumption, children’s intake is below the recommended levels. A randomized controlled trial for evaluating the effectiveness of a school-based intervention for increasing children’s fruit intake, with the teacher being the exposure model, was designed. Two hundred eighteen elementary school students (aged 9 years) in Cyprus were randomly assigned into two 1-year intervention groups, the Educational Material group (EDUC) (n=59) and the Exposure group (EXPO) (n=67), or a control group (n=58). Children’s dietary intake was assessed through 2-day dietary records before the intervention began (October 2008), at the end of the intervention (June 2009), and at 1-year follow-up (June 2010). Students in the EDUC group received a weekly educational program for increasing awareness and improving skills regarding fruit preparation/consumption and students in the EXPO group were exposed to the consumption of a fruit on a daily basis by their teacher. The control group members received no intervention. Repeated measures analysis of variance was used to evaluate the group effect and the time×group interaction. Higher fruit intake was reported by the children in the EXPO and the EDUC groups compared with the control group at the end of the intervention: a statistically significant group effect was found (P<0.001). At 1-year follow-up, results remained significant only for the children in the EXPO group (P<0.001). Exposure to fruit consumption by schoolteachers may be a more effective way for improving fruit intake of children compared with traditional educational approaches.
Source : Journal of the Academy of Nutrients + Dietetics
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Fruit and Vegetable Intakes Are Associated with Lower Risk of Bladder Cancer among Women in the Multiethnic Cohort Study1,2
Song-Yi Park3,7,*,Nicholas J. Ollberding4,7, Christy G. Woolcott5, Lynne R. Wilkens3, Brian E. Henderson6, and Laurence N. Kolonel3
- 3Cancer Epidemiology Program, University of Hawaii Cancer Center, Honolulu, HI
- 4Division of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
- 5Departments of Obstetrics, Gynecology, and Pediatrics, Dalhousie University, Halifax, NS, Canada; and
- 6Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA
Fruits and vegetables have been examined for their possible effects on the risk of bladder cancer, as they contain numerous nutrients, phytochemicals, and antioxidants with potentially anticarcinogenic properties. In a prospective analysis of 185,885 older adults participating in the Multiethnic Cohort Study, we examined whether the consumption of fruits and vegetables, or of nutrients concentrated in fruits and vegetables, was associated with bladder cancer risk. Cox proportional hazards models were used to calculate HRs and 95% CIs for bladder cancer in relation to dietary intakes. A total of 581 invasive bladder cancer cases (429 men and 152 women) were diagnosed over a mean follow-up period of 12.5 y. In women, total fruits and vegetables [HR = 0.35 (95% CI: 0.22, 0.56); highest vs. lowest quartile], total vegetables [HR = 0.49 (95% CI: 0.29, 0.83)], yellow-orange vegetables [HR = 0.48 (95% CI: 0.30, 0.77)], total fruits [HR = 0.54 (95% CI: 0.34, 0.85)], and citrus fruits [HR = 0.56 (95% CI: 0.34, 0.90)] were inversely associated with the risk of invasive bladder cancer in risk factor-adjusted models. In addition, women with the highest intakes of vitamins A, C, and E; the carotenoids α-carotene, β-carotene, and β-cryptoxanthin; and folate had a lower risk of bladder cancer. For men, no associations for fruits, vegetables, or nutrients were found overall, although inverse associations were observed for vegetable intake among current smokers, and in ethnic-specific analyses, for fruit and vegetable intake among Latinos specifically. Our findings suggest that greater consumption of fruits and vegetables may lower the risk of invasive bladder cancer among women and highlight the need for specific subgroup analyses in future studies.
Source : The Journal of Nutrition
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Fruit and vegetable intake and type 2 diabetes: EPIC-InterAct prospective study and meta-analysis
A J Cooper1, N G Forouhi1, Z Ye1, B Buijsse2, L Arriola3,4,5, B Balkau6,7, A Barricarte5,8, J W J Beulens9, H Boeing2, F L Büchner10, C C Dahm11,12, B de Lauzon-Guillain7,13, G Fagherazzi13, P W Franks14,15, C Gonzalez16, S Grioni17, R Kaaks18, T J Key19, G Masala20, C Navarro5,21,22, P Nilsson23, K Overvad11,12, S Panico24, J Ramón Quirós25, O Rolandsson15, N Roswall26, C Sacerdote27,28, M-J Sánchez5,29, N Slimani30, I Sluijs9, A M W Spijkerman10, B Teucher18, A Tjonneland31, R Tumino32,33, S J Sharp1, C Langenberg1, E J M Feskens34, E Riboli35, N J Wareham1 and The InterAct Consortium
Fruit and vegetable intake (FVI) may reduce the risk of type 2 diabetes (T2D), but the epidemiological evidence is inconclusive. The aim of this study is to examine the prospective association of FVI with T2D and conduct an updated meta-analysis. In the European Prospective Investigation into Cancer-InterAct (EPIC-InterAct) prospective case–cohort study nested within eight European countries, a representative sample of 16 154 participants and 12 403 incident cases of T2D were identified from 340 234 individuals with 3.99 million person-years of follow-up. For the meta-analysis we identified prospective studies on FVI and T2D risk by systematic searches of MEDLINE and EMBASE until April 2011. In EPIC-InterAct, estimated FVI by dietary questionnaires varied more than twofold between countries. In adjusted analyses the hazard ratio (95% confidence interval) comparing the highest with lowest quartile of reported intake was 0.90 (0.80–1.01) for FVI; 0.89 (0.76–1.04) for fruit and 0.94 (0.84–1.05) for vegetables. Among FV subtypes, only root vegetables were inversely associated with diabetes 0.87 (0.77–0.99). In meta-analysis using pooled data from five studies including EPIC-InterAct, comparing the highest with lowest category for FVI was associated with a lower relative risk of diabetes (0.93 (0.87–1.00)). Fruit or vegetables separately were not associated with diabetes. Among FV subtypes, only green leafy vegetable (GLV) intake (relative risk: 0.84 (0.74–0.94)) was inversely associated with diabetes. Subtypes of vegetables, such as root vegetables or GLVs may be beneficial for the prevention of diabetes, while total FVI may exert a weaker overall effect.
Source : European Journal of Clinical Nutrition (2012) 66, 1082–1092; doi:10.1038/ejcn.2012.85
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