Multi-Micronutrient Fortified Rice Improved Serum Zinc and Folate Concentrations of Cambodian School Children. A Double-Blinded Cluster-Randomized Controlled Trial

Review of dietary assessment studies conducted among Khmer populations living in Cambodia

Background

Despite economic growth, Cambodia continues to have high rates of malnutrition, anaemia and nutrition‐related deficiencies. Government policies promote nutrition strategies, although dietary intake data is limited. A detailed synthesis of existing intake data is needed to inform nutrition policy and practice change. This review aims to characterise and assess quality of dietary assessment methods and outcomes from individual‐level ‘whole diet’ studies of Khmer people living in Cambodia.

Methods

Searches were conducted using PRISMA‐ScR guidelines. Included papers reported dietary intake at an individual level for ‘whole diet’. Studies using secondary data or lacking dietary assessment details were excluded. Extracted data included dietary assessment features, nutrient/food group intakes and database.

Results

Nineteen publications (15 studies) were included, with nine carried out among children under 5 years and six among women. Eleven studies reported intake by food groups and four by nutrients, prominently energy, protein, vitamin A, iron, calcium and zinc. Inconsistent intakes, food groupings and reporting of study characteristics limited data synthesis. All but one study used 24‐h recalls. Trained local fieldworkers used traditional interview‐administered data collection and varied portion estimation tools. Food composition databases for analysis were not tailored to the Cambodian diet. Overall quality was rated as ‘good’.

Conclusions

We recommend the development of a best‐practice protocol for conducting dietary assessment, a Cambodia‐specific food composition database and a competent trained workforce of nutrition professionals, with global support of expertise and funding for future dietary assessment studies conducted in Cambodia.

Fifteen studies with highly variable intake data included in the review.

The food composition databases used were not specific to Cambodian diet.

Minimum reporting standards and best practice protocols recommended, including in‐country nutrition training.

Lack of whole population dietary intake data indicates the need for a national survey.

The Role of Micronutrients and Toxic Metals in the Management of Epidemics in Cambodia

The illegal trade of wildlife in SE Asia has been identified as the likely cause of the COVID-19 pandemic. We reviewed 198 papers on the current COVID pandemic in Cambodia, diseases such as avian influenza and Nipah virus, most likely to develop into a new pandemic in Cambodia, and common features of disease that require mitigation. Artisanal goldmining uses pure mercury in the areas where wildlife is smuggled to China. Moreover, 30-40% of Cambodians are zinc deficient. High levels of arsenic in irrigation water (>1000 µg/L) are associated with very low levels of zinc in rice (5 µg/g) and rice is the primary staple food for the region. Brown rice from nine of 15 paddy fields in the arsenic zone of Cambodia had double the new guidelines of 100 µg/kg inorganic arsenic for children's food in the EU and USA. The combination of deficiencies of essential micronutrients like zinc and pervasive presence of arsenic and mercury has the potential to compromise the immunity of many Cambodians. Innovative solutions are suggested to improve micronutrient nutrition. Toxins that suppress the immune system must be better managed to reduce the virulence of pathogens. Cambodia was not likely the source of the COVID-19 but does have problems that could result in a new pandemic.

Effects of Foods Fortified with Zinc, Alone or Cofortified with Multiple Micronutrients, on Health and Functional Outcomes: A Systematic Review and Meta-Analysis

Seventeen per cent of the world's population is estimated to be at risk of inadequate zinc intake, which could in part be addressed by zinc fortification of widely consumed foods. We conducted a review of efficacy and effectiveness studies to ascertain the effect of zinc fortification [postharvest fortification of an industrially produced food or beverage; alone or with multiple micronutrients (MMN)] on a range of health outcomes. Previous reviews have required that the effect of zinc be isolated; because zinc is always cofortified with MMN in existing fortification programs, we did not impose this condition. Outcomes assessed were zinc-related biomarkers (plasma or serum, hair or urine zinc concentrations, comet assay, plasma fatty acid concentrations, and the proportion of and total zinc absorbed in the intestine from the diet), child anthropometry, morbidity, mortality, cognition, plasma or serum iron and copper concentrations, and for observational studies, a change in consumption of the food vehicle. Fifty-nine studies were included in the review; 54 in meta-analyses, totaling 73 comparisons. Zinc fortification with and without MMN increased plasma zinc concentrations (efficacy, n = 27: 4.68 μg/dL; 95% CI: 2.62-6.75; effectiveness, n = 13: 6.28 μg/dL; 95% CI: 5.03-7.77 μg/dL) and reduced the prevalence of zinc deficiency (efficacy, n = 11: OR: 0.76, 95% CI: 0.60-0.96; effectiveness, n = 10: OR: 0.45, 95% CI: 0.31-0.64). There were statistically significant increases in child weight (efficacy, n = 11: 0.43 kg, 95% CI: 0.11-0.75 kg), improvements in short-term auditory memory (efficacy, n = 3: 0.32 point, 95% CI: 0.13-0.50 point), and decreased incidence of diarrhea (efficacy, n = 3: RR: 0.79, 95% CI: 0.68-0.92) and fever (efficacy, n = 2: RR: 0.85, 95% CI: 0.74-0.97). However, these effects cannot be solely attributed to zinc. Our review found that zinc fortification with or without MMN reduced the prevalence of zinc deficiency and may provide health and functional benefits, including a reduced incidence of diarrhea.

Scoping review of nutrition intervention and dietary assessment studies in Khmer populations living in Cambodia

BACKGROUND

This scoping review aims to describe the body of nutrition intervention and dietary assessment research undertaken with Khmer populations in Cambodia, as well as summarise the nutrition knowledge base and highlight priority areas for future research.

METHODS

Five databases and the grey literature were searched, following PRISMA-ScR guidelines. Studies involving dietary assessment or nutrition interventions published after 1992 were identified using specific search terms and extracted to a customised data extraction table for categorisation and analysis. Study participants were Khmer people of any age and gender, living in rural or urban Cambodia.

RESULTS

Of the 100 included studies, 58 were dietary assessment only studies, 24 were nutrition interventions only, and 18 studies involved both assessment of intake and an intervention. Sixty-eight percent of study populations were mothers and young children, of which 52 studies focused on children aged under 5 years. Nineteen interventions involved supplementation and six trialled fortification of rice or fish sauce. Anaemia was the most common nutrition condition studied (n = 17), followed by malnutrition (n = 15) and malnutrition risk factors (n = 11). General nutrition status was explored in 25 studies, and individual micronutrients that were studied included iron (n = 27), zinc (n = 6), vitamin A (n = 4) and thiamine (n = 3).

CONCLUSIONS

Diet-related research in Khmer populations in Cambodia has predominantly focused on dietary assessment or evaluation of interventions aimed at reducing malnutrition and resolving micronutrient deficiencies. Areas identified as emerging needs included non-communicable diseases, the ageing population and non-iron deficiency anaemia.