Food environment research in low- and middle-income countries: a systematic scoping review

Food environment research is increasingly gaining prominence in low- and middle-income countries (LMICs). However, in the absence of a systematic review of the literature, little is known about the emerging body of evidence from these settings. This systematic scoping review aims to address this gap. A systematic search of 6 databases was conducted in December 2017 and retrieved 920 records. In total, 70 peer-reviewed articles met the eligibility criteria and were included. Collectively, articles spanned 22 LMICs, including upper-middle-income countries (n = 49, 70%) and lower-middle-income countries (n = 18, 26%). No articles included low-income countries. Articles featured quantitative (n = 45, 64%), qualitative (n = 17, 24%), and mixed-method designs (n = 11, 8%). Studies analyzed the food environment at national, community, school, and household scales. Twenty-three articles (55%) assessed associations between food environment exposures and outcomes of interest, including diets (n = 14), nutrition status (n = 13), and health (n = 1). Food availability was associated with dietary outcomes at the community and school scales across multiple LMICs, although associations varied by vendor type. Evidence regarding associations between the food environment and nutrition and health outcomes was inconclusive. The paucity of evidence from high-quality studies is a severe limitation, highlighting the critical need for improved study designs and standardized methods and metrics. Future food environment research must address low-income and lower-middle-income countries, and include the full spectrum of dietary, nutrition, and health outcomes. Improving the quality of food environment research will be critical to the design of feasible, appropriate, and effective interventions to improve public health nutrition in LMICs

Using a global food environment framework to understand relationships with food choice in diverse low- and middle-income countries

This study aimed to determine if the Turner et al. (2018) framework allows researchers to identify and study relationships between food environments and individual food choice in diverse contexts and if updates to the framework are warranted. We mapped evidence from 15 drivers of food choice projects to the framework, using thematic analysis to identify common drivers within the food environment across countries and emergent characteristics not listed in the framework. The framework contained breadth and depth of content necessary to identify common drivers – prices and affordability, availability, and vendor and product properties. Insights regarding common drivers and emergent characteristics may inform iterative development of conceptual and empirical research and reinforce current strategies seeking to improve nutrition and health outcomes in LMICs through targeted policies and interventions

Anthocyanidins and anthocyanins: colored pigments as food, pharmaceutical ingredients, and the potential health benefits

Anthocyanins are colored water-soluble pigments belonging to the phenolic group. The pigments are in glycosylated forms. Anthocyanins responsible for the colors, red, purple, and blue, are in fruits and vegetables. Berries, currants, grapes, and some tropical fruits have high anthocyanins content. Red to purplish blue-colored leafy vegetables, grains, roots, and tubers are the edible vegetables that contain a high level of anthocyanins. Among the anthocyanin pigments, cyanidin-3-glucoside is the major anthocyanin found in most of the plants. The colored anthocyanin pigments have been traditionally used as a natural food colorant. The color and stability of these pigments are influenced by pH, light, temperature, and structure. In acidic condition, anthocyanins appear as red but turn blue when the pH increases. Chromatography has been largely applied in extraction, separation, and quantification of anthocyanins. Besides the use of anthocyanidins and anthocyanins as natural dyes, these colored pigments are potential pharmaceutical ingredients that give various beneficial health effects. Scientific studies, such as cell culture studies, animal models, and human clinical trials, show that anthocyanidins and anthocyanins possess antioxidative and antimicrobial activities, improve visual and neurological health, and protect against various non-communicable diseases. These studies confer the health effects of anthocyanidins and anthocyanins, which are due to their potent antioxidant properties. Different mechanisms and pathways are involved in the protective effects, including free-radical scavenging pathway, cyclooxygenase pathway, mitogen-activated protein kinase pathway, and inflammatory cytokines signaling. Therefore, this review focuses on the role of anthocyanidins and anthocyanins as natural food colorants and their nutraceutical properties for health. Abbreviations: CVD: Cardiovascular disease VEGF: Vascular endothelial growth factor

Foodscapes, Foodways, and Nutrition Transitions in Urban Mexico

The global surge in obesity and associated degenerative health conditions, such as diabetes and heart disease, have potentially crushing consequences for households, communities, health systems, and national economies. Mexico has one of the highest prevalence levels of overweight and obesity in the world, yet at a lower income per capita than its peers among highly overweight countries. It has recorded the fastest rate of change in obesity globally as well as a surge in diabetes mortality. As incidence of obesity increases nationally and becomes a widespread public health issue, it is becoming concentrated in the low-income population. In Mexico, low-income families are migrating from undernutriton not to good nutrition but rather to equally debilitating conditions of obesity and diet-related diseases. Using a social-ecological approach, I argue that there are a number of broad, global forces driving rising rates of obesity worldwide. However, national and community-level environmental, economic, social, and cultural factors mitigate or reinforce global pressures and risks. This dissertation seeks to present a more nuanced understanding of the obesity-promoting dietary changes that have occurred in Mexico over the past two decades, with particular concern for how social class shapes local food environments, eating patterns, and vulnerability to obseogenic diets. In this study, I combine national-level economic analysis with ethnographic methods used by urban geographers and applied anthropologists to analyze national economic and food system trends as well as local food acquisition, preparation, and consumption environments and practices in three urban communities of distinct socioeconomic status. I use a variety of quantitative and qualitative methods to investigate the macrostructures and microprocesses underlying the dietary changes that are occurring, examining factors—risk regulators—that exacerbate or mitigate vulnerability to obseogenic eating patterns. This investigation contributes to a growing body of public health research that emphasizes direct observation of neighborhood attributes to understand the health-promoting or health-inhibiting aspects of people’s physical environments as well as the role of social class in these environments. This work refines Popkin’s general nutrition transition theory by incorporating perspectives from the public health social-ecological framework, health geography, economics and behavioral economics, and sociological theory as well as and phenomenological insights gained from ethnographic research in a middle-income country undergoing astonishingly rapid dietary change. The research and analysis presented in this dissertation yield theoretical, substantive, and methodological insights that should be useful in crafting public policies that can channel and shape nutrition transitions to better support human health

The accumulation of reproductive incompatibilities in African cichlid fish.

The rate at which different components of reproductive isolation accumulate with divergence time between species has only been studied in a limited, but growing, number of species. We measured premating isolation and hybrid inviability at four different ontogenetic stages from zygotes to adults in interspecific hybrids of 26 pairs of African cichlid species, spanning the entire East African haplochromine radiation. We then used multiple relaxed molecular clock calibrations to translate genetic distances into absolute ages to compare evolutionary rates of different components of reproductive isolation. We find that premating isolation accumulates fast initially but then changes little with increasing genetic distance between species. In contrast, postmating isolation between closely related species is negligible but then accumulates rapidly, resulting in complete hybrid inviability after 4.4/8.5/18.4 million years (my). Thus, the rate at which complete intrinsic incompatibilities arise in this system is orders of magnitude lower than rates of speciation within individual lake radiations. Together these results suggest divergent ecological adaptations may prevent populations from interbreeding and help maintain cichlid species diversity, which may be vulnerable to environmental degradation. By quantifying the capacity to produce viable hybrids between allopatric, distantly related lineages our results also provide an upper divergence time limit for the "hybrid swarm origin" model of adaptive radiation