Iron deficiency is the most frequent nutritional deficiency in the world with an estimated 1.4 billion people affected. The usual way to fight iron deficiency is iron fortification, but this approach is not always effective and can have undesirable side effects including an increase in the growth and virulence of gut bacterial pathogens responsible for diarrhea and gut inflammation. Iron is mainly absorbed in the duodenum and is tightly regulated in mammals. Unabsorbed iron enters the colonic lumen where many microorganisms, referred to as gut microbiota, reside. Iron is essential for these bacteria, and its availability consequently affects this microbial ecosystem. The aim of this review is to provide further insights into the complex relationship between iron and gut microbiota. Given that overcoming anemia caused by iron deficiency is still a challenge today, gut microbiota could help identify more efficient ways to tackle this public health problem.
1 June 2016 in The American Journal of Clinical Nutrition
Dietary fiber is a complex nutritional concept whose definition and method of analysis has evolved over time. However, literature on the role of dietary fiber on mineral bioavailability has not followed pace. Although in vitro studies revealed mineral binding properties, both animal and human studies failed to show negative effects on mineral absorption, and even in some cases reported absorption enhancing properties. The existing literature suggests that dietary fibers have negative effects on mineral absorption in the gastrointestinal tract largely due to mineral binding or physical entrapment. However, colonic fermentation of dietary fibers may offset this negative effect by liberating bound minerals and promoting colonic absorption. However, existing studies are limited since they did not control for more potent mineral absorption inhibitors such as phytates and polyphenols. Animal studies have mostly been on rats and hence difficult to extrapolate to humans. Human studies have been mostly on healthy young men, who likely to have an adequate store of iron. The use of different types and amounts of fibers (isolated/added) with varying physiological and physicochemical properties makes it difficult to compare results. Future studies can make use of the opportunities offered by enzyme technologies to decipher the role of dietary fibers in mineral bioavailability.
Summary: This systematic review synthesized the qualitative evidence on factors influencing obesogenic behaviours in adolescent girls and women of reproductive age in low‐ and middle‐income countries (LMICs). This qualitative evidence synthesis followed the framework synthesis approach to extract, analyse and synthesize data. Electronic searches were conducted in the Web of Science, SCOPUS, CABI Abstracts, MEDLINE, PsycINFO and Google Scholar. Studies were eligible if they were conducted in LMICs, of qualitative nature, and reported obesogenic behaviours of female adolescents (10–19 years of age) or women of reproductive age (15–49 years of age). The review resulted in 71 included studies from 27 different countries. Thirty‐two studies focused on dietary behaviours, 17 on physical activity and 22 on both behaviours. Gender norms and failures to recognize the importance of healthy behaviours across the life cycle were important factors. The abundance and promotion of affordable but unhealthy food, food safety concerns, taste preferences and social desirability of foods drive consumption of unhealthy foods. Busy lives and limited exercise spaces keep girls and women from being physically active. Obesogenic behaviours of adolescent girls and women of reproductive age are influenced by factors at individual, social, physical and environmental levels and require diverse solutions to address these factors in LMICs.
8 August 2013 in International Journal of Food Science and Technology
Objective: To assess factors influencing dietary behaviours of adolescents in Addis Ababa, Ethiopia.Design: Using the qualitative participatory method Photovoice, participants received training on the basics of Photovoice and took photographs related to (un)healthy eating in their environment. Transcripts of individual interviews, focus group discussions and photographs were coded for thematic analysis.Setting: One private and one public school located in the same, central neighbourhood in Addis Ababa, Ethiopia to explore how school populations of different socio-economic status experience the same neighbourhood environment.Participants: Twenty-six adolescents aged 14–19 years old, of which there were seventeen girls and nine boys.Results: Findings from the current study indicate that food safety concerns appear to be the major influencing factors for adolescents’ dietary choices. Unhealthy and unsafe foods appear to be widely available and/or affordable in adolescents’ neighbourhoods and almost half of the photographs taken by adolescents depicted poor hygiene conditions related to food vendors. Participants considered foods available in their environments as generally unsafe, calling for more packaged food.Conclusions: Concerns for food safety, hygiene and affordability are the dominating factors for adolescents’ food choices. These concerns, together with limited nutrition knowledge and preference for packaged foods, could make cheap, ultra-processed packaged foods more desirable.