[Show abstract][Hide abstract] ABSTRACT: We have previously reported low concentrations of plasma ascorbate and low dietary vitamin C intake in the older Indian population and a strong inverse association of these with cataract. Little is known about ascorbate levels in aqueous humor and lens in populations habitually depleted of ascorbate and no studies in any setting have investigated whether genetic polymorphisms influence ascorbate levels in ocular tissues. Our objectives were to investigate relationships between ascorbate concentrations in plasma, aqueous humor and lens and whether these relationships are influenced by Single Nucleotide Polymorphisms (SNPs) in sodium-dependent vitamin C transporter genes (SLC23A1 and SLC23A2). We enrolled sixty patients (equal numbers of men and women, mean age 63 years) undergoing small incision cataract surgery in southern India. We measured ascorbate concentrations in plasma, aqueous humor and lens nucleus using high performance liquid chromatography. SLC23A1 SNPs (rs4257763, rs6596473) and SLC23A2 SNPs (rs1279683 and rs12479919) were genotyped using a TaqMan assay. Patients were interviewed for lifestyle factors which might influence ascorbate. Plasma vitamin C was normalized by a log10 transformation. Statistical analysis used linear regression with the slope of the within-subject associations estimated using beta (β) coefficients. The ascorbate concentrations (μmol/L) were: plasma ascorbate, median and inter-quartile range (IQR), 15.2 (7.8, 34.5), mean (SD) of aqueous humor ascorbate, 1074 (545) and lens nucleus ascorbate, 0.42 (0.16) (μmol/g lens nucleus wet weight). Minimum allele frequencies were: rs1279683 (0.28), rs12479919 (0.30), rs659647 (0.48). Decreasing concentrations of ocular ascorbate from the common to the rare genotype were observed for rs6596473 and rs12479919. The per allele difference in aqueous humor ascorbate for rs6596473 was −217 μmol/L, p < 0.04 and a per allele difference in lens nucleus ascorbate of −0.085 μmol/g, p < 0.02 for rs12479919. The β coefficients for the regression of log10 plasma ascorbate on aqueous humor ascorbate were higher for the GG genotype of rs6596473: GG, β = 1460 compared to carriage of the C allele, CG, β = 1059, CC, β = 1132, p interaction = 0.1. In conclusion we found that compared to studies in well-nourished populations, ascorbate concentrations in the plasma, aqueous humor and lens nucleus were low. We present novel findings that polymorphisms in SLC23A1/2 genes influenced ascorbate concentration in aqueous humor and lens nucleus.
Experimental Eye Research 07/2014; · 3.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Elevated plasma homocysteine is a risk factor for Alzheimer disease, but the relevance of homocysteine lowering to slow the rate of cognitive aging is uncertain.OBJECTIVE: The aim was to assess the effects of treatment with B vitamins compared with placebo, when administered for several years, on composite domains of cognitive function, global cognitive function, and cognitive aging.DESIGN: A meta-analysis was conducted by using data combined from 11 large trials in 22,000 participants. Domain-based z scores (for memory, speed, and executive function and a domain-composite score for global cognitive function) were available before and after treatment (mean duration: 2.3 y) in the 4 cognitive-domain trials (1340 individuals); Mini-Mental State Examination (MMSE)-type tests were available at the end of treatment (mean duration: 5 y) in the 7 global cognition trials (20,431 individuals).RESULTS: : The domain-composite and MMSE-type global cognitive function z scores both decreased with age (mean ± SE: -0.054 ± 0.004 and -0.036 ± 0.001/y, respectively). Allocation to B vitamins lowered homocysteine concentrations by 28% in the cognitive-domain trials but had no significant effects on the z score differences from baseline for individual domains or for global cognitive function (z score difference: 0.00; 95% CI: -0.05, 0.06). Likewise, allocation to B vitamins lowered homocysteine by 26% in the global cognition trials but also had no significant effect on end-treatment MMSE-type global cognitive function (z score difference: -0.01; 95% CI: -0.03, 0.02). Overall, the effect of a 25% reduction in homocysteine equated to 0.02 y (95% CI: -0.10, 0.13 y) of cognitive aging per year and excluded reductions of >1 mo per year of treatment.CONCLUSION: Homocysteine lowering by using B vitamins had no significant effect on individual cognitive domains or global cognitive function or on cognitive aging.
American Journal of Clinical Nutrition 06/2014; · 6.50 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Increasing prevalence of overweight and obesity has led policy-makers to consider health-related taxes to limit the consumption of unhealthy foods and beverages. Such taxes are currently already in place in countries in Europe (e.g. Hungary, France and Finland) and in various states in the USA. Although these taxes are possibly efficient in reducing by a small amount the consumption of targeted products if the tax is fully transmitted to the consumer, there is too little available evidence on what will be consumed instead and whether these food substitutions undermine the hoped-for health benefits of the tax. We also know very little on how the food supply side will respond and what overall impact this will have. Without a proper appreciation of the potential indirect impacts we do not know the overall impact of taxes foods on unhealthy foods and beverages and further that there is a very real possibility that they may not be beneficial for health after all.
Journal of Public Health 05/2014; · 2.30 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective
To estimate the burden of diarrhoeal diseases from exposure to inadequate water, sanitation and hand hygiene in low- and middle-income settings and provide an overview of the impact on other diseases.Methods
For estimating the impact of water, sanitation and hygiene on diarrhoea, we selected exposure levels with both sufficient global exposure data and a matching exposure-risk relationship. Global exposure data were estimated for the year 2012, and risk estimates were taken from the most recent systematic analyses. We estimated attributable deaths and disability-adjusted life years (DALYs) by country, age and sex for inadequate water, sanitation and hand hygiene separately, and as a cluster of risk factors. Uncertainty estimates were computed on the basis of uncertainty surrounding exposure estimates and relative risks.ResultsIn 2012, 502 000 diarrhoea deaths were estimated to be caused by inadequate drinking water and 280 000 deaths by inadequate sanitation. The most likely estimate of disease burden from inadequate hand hygiene amounts to 297 000 deaths. In total, 842 000 million diarrhoea deaths are estimated to be caused by this cluster of risk factors, which amounts to 1.5% of the total disease burden and 58% of diarrhoeal diseases. In children under 5 years old, 361 000 deaths could be prevented, representing 5.5% of deaths in that age group.Conclusions
This estimate confirms the importance of improving water and sanitation in low- and middle-income settings for the prevention of diarrhoeal disease burden. It also underscores the need for better data on exposure and risk reductions that can be achieved with provision of reliable piped water, community sewage with treatment and hand hygiene.
Tropical Medicine & International Health 04/2014; · 2.30 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background: For the poor, a diverse, locally acceptable, nutrient-rich food supply is often inaccessible, leading to the consumption of low quality diets. Value chain analysis (VCA) has been proposed to support the identification of solutions to food supply problems, however little evidence of its usefulness for this purpose exists. This case study aimed to determine how fruit and vegetable value chains in Fiji where poor diets and high rates of diet-related disease have been identified contribute to product accessibility and acceptability in urban areas and to assess the benefit of VCA in identifying opportunities for intervention. Methods: Focus groups were used to establish the fruit and vegetable attributes acceptable to and valued by consumers. Following this, a series of workshops, interviews, and observations with chain actors and stakeholders were used to map three exemplar fruit and vegetable chains and assess their ability to make acceptable and valued fresh products accessible to the urban population. Results: Urban Fijians are motivated to consume fresh, local produce, but often find the supply to be inconsistent, low quality, and unaffordable. Value chain characteristics that contribute to these supply challenges include poor infrastructure (e.g. roads and water supplies), limited access to agricultural inputs, sub-optimal post-harvest care and handling, and strained relationships between chain actors. Discussion: Several points in the exemplar chains where targeted intervention could lead to improved accessibility and acceptability were identified. These findings suggest a benefit to the use of VCA as a tool for identifying promising solutions to nutrition problems.
141st APHA Annual Meeting and Exposition 2013; 11/2013
[Show abstract][Hide abstract] ABSTRACT: We employ a single-country dynamically-recursive Computable General Equilibrium model to make health-focussed macroeconomic assessments of three contingent UK Greenhouse Gas (GHG) mitigation strategies, designed to achieve 2030 emission targets as suggested by the UK Committee on Climate Change. In contrast to previous assessment studies, our main focus is on health co-benefits additional to those from reduced local air pollution. We employ a conservative cost-effectiveness methodology with a zero net cost threshold. Our urban transport strategy (with cleaner vehicles and increased active travel) brings important health co-benefits and is likely to be strongly cost-effective; our food and agriculture strategy (based on abatement technologies and reduction in livestock production) brings worthwhile health co-benefits, but is unlikely to eliminate net costs unless new technological measures are included; our household energy efficiency strategy is likely to breakeven only over the long term after the investment programme has ceased (beyond our 20 year time horizon). We conclude that UK policy makers will, most likely, have to adopt elements which involve initial net societal costs in order to achieve future emission targets and longer-term benefits from GHG reduction. Cost-effectiveness of GHG strategies is likely to require technological mitigation interventions and/or demand-constraining interventions with important health co-benefits and other efficiency-enhancing policies that promote internalization of externalities. Health co-benefits can play a crucial role in bringing down net costs, but our results also suggest the need for adopting holistic assessment methodologies which give proper consideration to welfare-improving health co-benefits with potentially negative economic repercussions (such as increased longevity).
[Show abstract][Hide abstract] ABSTRACT: Older people are at increased risk of vitamin B12 deficiency and the provision of fortified foods may be an effective way to ensure good vitamin B12 status in later life.Aim: To evaluate the effectiveness of a vitamin B12 fortified food provided by a national program of complementary food for older people on plasma vitamin B12 levels.Subjects and methods: A random sub-sample of 351 subjects aged 65-67y from a large cluster randomised controlled trial provided blood samples at baseline and after 24 months of intervention. The intervention arm (10 clusters 186 participants) received a vitamin B12 fortified food designed to deliver 1.4 mug/day, while the control arm did not receive complementary food (10 clusters, 165 participants). Serum vitamin B12 and folate levels determined by radioimmunoassay were used to estimate the effect of intervention on vitamin B12 levels, adjusting for baseline levels and sex.
Attrition at 24 months was 16.7% and 23.6% in the intervention and control arms respectively (p = 0.07). Over 24 months of intervention, mean (95% CI) serum vitamin B12 decreased from 392 (359--425) pmol/dL to 357 (300--414) pmol/dL (p < 0.07) in the intervention arm and from 395 (350--440) pmol/dL to 351 (308--395) pmol/dL in the control arm. There was no significant effect of the intervention on folate status.
Our findings suggest that foods fortified with 1.4 mug/daily vitamin B12 as provided by Chile's national programme for older people are insufficient to ensure adequate vitamin B12 levels in this population. Chile has a long and successful experience with nutrition intervention programs; however, the country's changing demographic and nutritional profiles require a constant adjustment of the programs.
[Show abstract][Hide abstract] ABSTRACT: Water, sanitation and hygiene (WASH) interventions are frequently implemented to reduce infectious diseases, and may be linked to improved nutrition outcomes in children.
To evaluate the effect of interventions to improve water quality and supply (adequate quantity to maintain hygiene practices), provide adequate sanitation and promote handwashing with soap, on the nutritional status of children under the age of 18 years and to identify current research gaps.
We searched 10 English-language (including MEDLINE and CENTRAL) and three Chinese-language databases for published studies in June 2012. We searched grey literature databases, conference proceedings and websites, reviewed reference lists and contacted experts and authors.
Randomised (including cluster-randomised), quasi-randomised and non-randomised controlled trials, controlled cohort or cross-sectional studies and historically controlled studies, comparing WASH interventions among children aged under 18 years.
Two review authors independently sought and extracted data on childhood anthropometry, biochemical measures of micronutrient status, and adherence, attrition and costs either from published reports or through contact with study investigators. We calculated mean difference (MD) with 95% confidence intervals (CI). We conducted study-level and individual-level meta-analyses to estimate pooled measures of effect for randomised controlled trials only.
Fourteen studies (five cluster-randomised controlled trials and nine non-randomised studies with comparison groups) from 10 low- and middle-income countries including 22,241 children at baseline and nutrition outcome data for 9,469 children provided relevant information. Study duration ranged from 6 to 60 months and all studies included children under five years of age at the time of the intervention. Studies included WASH interventions either singly or in combination. Measures of child anthropometry were collected in all 14 studies, and nine studies reported at least one of the following anthropometric indices: weight-for-height, weight-for-age or height-for-age. None of the included studies were of high methodological quality as none of the studies masked the nature of the intervention from participants.Weight-for-age, weight-for-height and height-for-age z-scores were available for five cluster-randomised controlled trials with a duration of between 9 and 12 months. Meta-analysis including 4,627 children identified no evidence of an effect of WASH interventions on weight-for-age z-score (MD 0.05; 95% CI -0.01 to 0.12). Meta-analysis including 4,622 children identified no evidence of an effect of WASH interventions on weight-for-height z-score (MD 0.02; 95% CI -0.07 to 0.11). Meta-analysis including 4,627 children identified a borderline statistically significant effect of WASH interventions on height-for-age z-score (MD 0.08; 95% CI 0.00 to 0.16). These findings were supported by individual participant data analysis including information on 5,375 to 5,386 children from five cluster-randomised controlled trials.No study reported adverse events. Adherence to study interventions was reported in only two studies (both cluster-randomised controlled trials) and ranged from low (< 35%) to high (> 90%). Study attrition was reported in seven studies and ranged from 4% to 16.5%. Intervention cost was reported in one study in which the total cost of the WASH interventions was USD 15/inhabitant. None of the studies reported differential impacts relevant to equity issues such as gender, socioeconomic status and religion.
The available evidence from meta-analysis of data from cluster-randomised controlled trials with an intervention period of 9-12 months is suggestive of a small benefit of WASH interventions (specifically solar disinfection of water, provision of soap, and improvement of water quality) on length growth in children under five years of age. The duration of the intervention studies was relatively short and none of the included studies is of high methodological quality. Very few studies provided information on intervention adherence, attrition and costs. There are several ongoing trials in low-income country settings that may provide robust evidence to inform these findings.
[Show abstract][Hide abstract] ABSTRACT: To quantify the relation between food prices and the demand for food with specific reference to national and household income levels.
Systematic review with meta-regression.
Online databases of peer reviewed and grey literature (ISI Web of Science, EconLit, PubMed, Medline, AgEcon, Agricola, Google, Google Scholar, IdeasREPEC, Eldis, USAID, United Nations Food and Agriculture Organization, World Bank, International Food Policy Research Institute), hand searched reference lists, and contact with authors.
We included cross sectional, cohort, experimental, and quasi-experimental studies with English abstracts. Eligible studies used nationally representative data from 1990 onwards derived from national aggregate data sources, household surveys, or supermarket and home scanners.
The primary outcome extracted from relevant papers was the quantification of the demand for foods in response to changes in food price (own price food elasticities). Descriptive and study design variables were extracted for use as covariates in analysis. We conducted meta-regressions to assess the effect of income levels between and within countries on the strength of the relation between food price and demand, and predicted price elasticities adjusted for differences across studies.
136 studies reporting 3495 own price food elasticities from 162 different countries were identified. Our models predict that increases in the price of all foods result in greater reductions in food consumption in poor countries: in low and high income countries, respectively, a 1% increase in the price of cereals results in reductions in consumption of 0.61% (95% confidence interval 0.56% to 0.66%) and 0.43% (0.36% to 0.48%), and a 1% increase in the price of meat results in reductions in consumption of 0.78% (0.73% to 0.83%) and 0.60% (0.54% to 0.66%). Within all countries, our models predict that poorer households will be the most adversely affected by increases in food prices.
Changes in global food prices will have a greater effect on food consumption in lower income countries and in poorer households within countries. This has important implications for national responses to increases in food prices and for the definition of policies designed to reduce the global burden of undernutrition.
[Show abstract][Hide abstract] ABSTRACT: To systematically review the available evidence on whether national or international agricultural policies that directly affect the price of food influence the prevalence rates of undernutrition or nutrition-related chronic disease in children and adults.
We systematically searched five databases for published literature (MEDLINE, EconLit, Agricola, AgEcon Search, Scopus) and systematically browsed other databases and relevant organisational websites for unpublished literature. Reference lists of included publications were hand-searched for additional relevant studies. We included studies that evaluated or simulated the effects of national or international food-price-related agricultural policies on nutrition outcomes reporting data collected after 1990 and published in English.
Prevalence rates of undernutrition (measured with anthropometry or clinical deficiencies) and overnutrition (obesity and nutrition-related chronic diseases including cancer, heart disease and diabetes).
We identified a total of four relevant reports; two ex post evaluations and two ex ante simulations. A study from India reported on the undernutrition rates in children, and the other three studies from Egypt, the Netherlands and the USA reported on the nutrition-related chronic disease outcomes in adults. Two of the studies assessed the impact of policies that subsidised the price of agricultural outputs and two focused on public food distribution policies. The limited evidence base provided some support for the notion that agricultural policies that change the prices of foods at a national level can have an effect on population-level nutrition and health outcomes.
A systematic review of the available literature suggests that there is a paucity of robust direct evidence on the impact of agricultural price policies on nutrition and health.
[Show abstract][Hide abstract] ABSTRACT: In 2003, the UK Food Standards Agency and the Department of Health began attempts to reduce national salt intakes via reformulation of processed foods and a consumer awareness campaign on the negative impacts of salt on health. The present study uses large nationally representative samples of households in England to assess whether discretionary salt use was affected by the national salt reduction campaign. Large cross-sectional datasets from the Health Survey for England were used to analyse trends in adults adding salt at the table between 1997 and 2007. Since 1997, there has been a steady decline in salt use at the table. Ordinal logistic regression analysis controlling for age, sex, total household income, region, ethnicity and background trends revealed that the reduction in salt use was significantly greater after the campaign (OR 0·58; 95 % CI 0·54, 0·63). Women (OR 0·71; 95 % CI 0·68, 0·74), non-white ethnic groups (OR 0·69; 95 % CI 0·62, 0·77), high-income households (OR 0·75; 95 % CI 0·69, 0·82), middle-income households (OR 0·79; 95 % CI 0·75, 0·84) and households in central (OR 0·90; 95 % CI 0·84, 0·98) or the south of England (OR 0·82; 95 % CI 0·77, 0·88) were less likely to add salt at the table. The results extend previous evidence of a beneficial response to the salt campaign by demonstrating the effect on salt use at the table. Future programmatic and research efforts may benefit from targeting specific population groups and improving the evidence base for evaluating the impact of the campaign.
The British journal of nutrition 01/2013; · 3.45 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objectives: The effectiveness of community level interventions depends to a great extent on adherence. Currently, information on factors related to adherence in older adults from developing countries is scarce. Our aim was to identify factors associated to adherence to a physical activity intervention in older adults from a post-transitional middle income country. Design, setting and participants: Using a combination of quantitative and qualitative methods we studied 996 older Chilean subjects (65-67.9 years at baseline) with low to medium socioeconomic status from 10 health centers randomized to receive a physical activity intervention as part of the CENEX cluster trial (ISRCTN48153354). Measurements: Using a multilevel regression model, the relationship between adherence (defined a priori as attendance at a minimum of 24 physical activity classes spread over at least 12 months) and individual, intervention-related and contextual factors was evaluated. We also conducted 40 semi-structured interviews with older adults (n=36) and instructors (n=4). Transcripts of the interviews were analyzed using content analysis to identify barriers and facilitators to adherence. Results: Adherence to physical activity intervention was 42.6% (CI 95% 39.5 to 45.6). Depression, diabetes mellitus, percentage of impoverished households and rate of arrests for violent crimes in the neighborhood predicted less adherence (p<0.05) while being retired, participation in physical activity prior to the intervention, and green areas per habitant were positively associated with adherence (p<0.05). The qualitative interviews identified three primary barriers to adherence: current health problems, lack of time due to commitments for caring for family members, and being employed, and two primary facilitators to adherence: the health benefits attributed to the intervention and the opportunity the classes provided for social interaction with others. Conclusion: In order to enhance effectiveness of community exercise interventions, strategies to improve participation should be targeted to older adults from deprived areas and those with psychological and medical conditions.
The Journal of Nutrition Health and Aging 01/2013; 17(5):466-71. · 2.39 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background
The UK Government has set specific targets for greenhouse gas emissions to lower the risk of dangerous climate change. Previous research has shown that important health co-benefits could result from strategies targeting the domains of transport, built environment, and agriculture. This study assesses the full general equilibrium economy-wide macroeconomic effects of health co-benefits from three similar UK strategies to meet locally specific 2030 greenhouse gas emission targets.Methods
Economy-wide effects of health co-benefits were modelled with a dynamic extension of the widely used International Food Policy Research Institute standard computable general equilibrium model for 2011–30. Four forms of economic agents are modelled: firms (who combine resource inputs to maximise profits), consumers (who consume and save to maximise their welfare), government, and foreign agents. The method consists of simulation of three greenhouse gas policy scenarios and a counterfactual do-nothing scenario. Basic health co-benefits (years lived with disability [YLD] and years of life lost [YLL]) were measured for a range of illnesses, on the basis of the comparative risk assessment approach. Combined with incidence numbers and prevalence trends, these basic YLD (morbidity) and YLL (mortality) co-benefits were used to calculate dynamic sequences of demographic and labour market effects on population and productive labour supply, and public budget implications for averted health-care costs and increased social security transfers (including benefit payments for working-age individuals and pension payments for old-age individuals). These economic shocks were subsequently imposed on the computable general equilibrium model and used to measure the combined macroeconomic effect of health co-benefits. The method for measuring averted health-care costs was published in The Lancet in 2012. Three scenarios were modelled: active travel (transport sector; health co-benefits of an assumed transformation of urban transport behaviour to reduce motorised transportation and increase walking [2·5-times] and cycling [8·0-times] in urban England and Wales); healthy diet (food and agriculture sector; health co-benefits of an assumed UK-wide 30% reduction in consumption of dietary saturated fat); and household energy (household energy sector; health co-benefits of an assumed UK-wide improvement in home insulation and ventilation, including reduced household energy use, improved indoor temperature, and associated changes in indoor pollutants).FindingsFor all scenarios, the macroeconomic effects of health co-benefits are positive. Overall, substantial savings on health-care costs represent the main contributing factor. Increased labour supplies also contribute positively, whereas increased social security transfers (due to larger working-age and old-age population segments) detract. The largest potential cumulative gross domestic product gains from health co-benefits are associated with the active travel scenario (around £19 billion), in which increased physical activity averts large-scale and long-term chronic disease burdens and health-system costs. The healthy diet scenario also leads to important potential gains (around £5 billion), whereas the full potential health co-benefits from the household energy scenario will not be realised until beyond 2030. Three economic sensitivity analyses were undertaken to test the sensitivity of results to variations in assumptions concerning: the substitutability of labour for other factors of production; the effectiveness of the interventions; and changes in the discount rate (the present value of the economic effects). Overall, the core results can be considered relatively robust to changes in these three factors.InterpretationStrategies to reduce greenhouse gas emissions and improve health are likely to result in substantial and increasing positive contributions to the economy. This effect might offset some economic costs and thereby allow such strategies to be seen more favourably, especially in times of economic austerity.FundingDepartment of Health Policy Research Programme.
The Lancet 11/2012; 380:S52. · 39.21 Impact Factor