Micronutrient malnutrition

Micronutrient deficiencies (iron, zinc, vitamin A and iodine) are widespread in low income and emerging countries affecting mortality, morbidity, educability and work productivity. Our aim is to study efficacy of innovative food-based approaches that optimize intake of bioavailable micronutrients and nutrition status of women and children in their first 1,000 days.

Micronutrient deficiencies (iron, zinc, vitamin A and iodine) are widespread in low- and middle income and countries affecting mortality, morbidity, educability and work productivity. Our aim is to study efficacy of innovative food-based approaches that optimize intake of bioavailable micronutrients and nutrition status of infants, children, adolescents, and women.

Currently, the focus of our research is on assessing efficacy of approaches like dietary diversity and (bio)fortification to increase micronutrient intake and status. Bioavailability of micronutrients from foods and ways to improve this are studied. Outcome measures also comprise acceptability of approaches and effects on functional outcomes like cognitive development and well-being. Heterogeneity of response to interventions due to biological (e.g. gene-micronutrient interactions), environmental (e.g. agriculture) and behavioural (e.g. food choice) factors are investigated, including development and testing of (early) indicators.

Research topics

Research focuses on delivering proof-of-principle evidence of  the efficacy of innovative food-based approaches with focus on preventing micronutrient deficiencies among women, children and adolescents in low- and middle- income countries.

Primary outcomes are related to dietary intake, (micro)nutrient status and growth, but also effects on functional outcomes such as gut permeability, gut microbiome, cognitive development. Bioavailability of the micronutrients ingested is an important topic of research as mainly determines whether consumed micronutrient is used by the body for its physiological functions.

Current key projects

Bioconversion of dietary pro-vitamin A to retinol

Vitamin A deficiency is a major nutritional burden in Sub-Saharan Africa, where diets are generally void of retinol. The bioavailability of plant-based derived pro-vitamin A carotenoids, especially of β-carotene, is low, but accurate pro-vitamin A bioequivalence values for mixed African diets do not exist. Genetic factors responsible for the conversion of pro-vitamin A to retinol in the human body are also important, since these seem to differ between Africans and Caucasians. Accurate bioequivalence values are important for setting dietary recommendations, designing interventions and formulating effective policies that fit in the context. The main aim of this study is to determine the bioequivalence of pro-vitamin A carotenoids from an indigenous African diet. For this, a novel isotope dilution technique is being developed.

Bioavailability of iron and zinc from edible insects

The global human population is growing rapidly and is expected to reach 9 billion individuals by 2050, requiring an increase of the global food production of 70% to guarantee food security.  Increasing the production of livestock is seriously constrained by the agricultural land available and will aggravate climate-change. The ecological footprint of the production of insects is much smaller than for the production of conventional meat: insects have a higher feed-to-body-mass conversion factor than most livestock species, thus requiring less feed to produce one unit of edible protein, and insects produce substantially lower amounts of greenhouse gases per unit of edible protein produced. Therefore, insects receive increasing attention for their potential to alleviate the projected protein shortage by 2050. So far, little attention has been paid to an additional important benefit of insects as food, i.e. their high levels of minerals such as iron and zinc. In collaboration with colleagues from the WU Plant Sciences group, Laboratory of Entomology and ETH Zürich, we have started up studies to assess the absorption of iron and zinc from edible insects, and to evaluate the potential of edible insects to improve iron and zinc status. The project is funded by the Wellcome Trust as a pilot project within the strategic priority platform Our Planet Our Health.

Ten2Twenty: adolescent nutrition

Adolescents make up 12% of the population in industrialized countries, compared with 19% in low and middle income countries. Adolescence is a period characterized by rapid growth and development reflected in high nutrient demands. As female adolescents are the bearers of the next generation, the main focus in current nutrition research is on girls. Early menarche (before 11 years of age) increases the risk of abdominal type obesity, glucose intolerance and insulin resistance, cardiovascular risk, coronary heart disease, and increased cancer mortality (especially breast cancer). Women with earlier menarche reach a shorter height compared to women who have menarche at a later stage. Late menarche (above 16 years of age) increases the risk of osteoporosis, adolescent depression and social anxiety symptoms. It is generally recognised that optimizing the nutrition status of adolescent girls is essential for their own health as well as, in case of teenage pregnancy, that of their off spring. The period of (pre-)adolescence may offer a unique second window of opportunity to, for example, remedy (nutrition-related) problems that occurred earlier in life as well as to foster a healthy transition from childhood to adulthood setting the stage for preventing or delaying adult-onset diet-related illnesses. There are many knowledge gaps in adolescent nutrition, however. The overall Ten2Twenty project is conducted in a range of low and middle income countries and aims to improve understanding of the interactions and interrelationships between nutritional, sociological and economic trajectories of optimizing adolescent nutrition for better health, pregnancy and birth outcome.

Biofortified cassava with provitamin A to improve vitamin A status (CASSAVITA II)

Nigeria is the largest producer of cassava worldwide and in some areas adults consume 950 g of cassava (raw fresh weight) per day on average. In comparison to East Africa, preparation methods of cassava based foods are different, which might affect the content and bioavailability of its pro-vitamin A. Therefore, we conducted a second randomized controlled trial (following CASSAVITA I, conducted in Kenya previously) to study the efficacy of yellow cassava, this time among preschool children in Nigeria. Preschool children are more vulnerable to vitamin A deficiency than older children and therefore form an important target group for this strategy.