Edible insects as a source of iron

Rationale: Sustainable diets are protective and respectful of biodiversity and ecosystems, culturally acceptable, accessible, and affordable; nutritionally adequate, safe and healthy; while optimizing natural and human resources. The fact that insects are a common food source for 2 billion people already provides excellent proof of its acceptability, especially in lower and middle income countries. In this project, we will carry out experiments to investigate the potential of insects as a source of iron when consumed as a common East African meal.



Objective: The primary objective is to assess the relative bioavailability of iron from insect (house cricket – Acheta domesticus) added to either a high- or low-phytate meal in humans and its potential to provide bioavailable iron. The secondary objectives are: To determine whether addition of edible house crickets enhances or inhibits the absorption of native or fortification iron from non-inhibitory or inhibitory meals



Study design: Single blind randomized partial Williams cross-over design



Study population: Twenty four (24) female volunteers, 18 - 30 years old with marginal iron status (ferritin <25 ng/ml) from the human volunteer database kept at the Division of Human Nutrition.



Intervention: Freeze dried and grinded house crickets labelled with 57Fe will be added to refined (non-inhibitory) maize porridge or to non-refined (inhibitory) maize porridge. Compared to two additional study test-meals which will contain 54Fe added to either non-refined/ refined maize porridge (inhibitory/ non-inhibitory food matrix respectively), the test meals will enable us to assess the relative bioavailability of iron from an house cricket-enriched low-phytate meal (non-inhibitory) or high-phytate (inhibitory) food matrix. The last two test meals will contain half the amount of freeze dried and grinded non-labelled house crickets labelled with 58FeSO4 added to either refined (non-inhibitory) or non-refined (inhibitory) maize porridge. These meals will enable us to answer the question whether edible house crickets enhance/inhibit absorption of native or fortificant iron in inhibitory and/or non-inhibitory meals.



Main study parameters/endpoints: The main study endpoint is the relative bioavailability (RBV) of iron from house crickets in a low phytate meal (non-inhibitory food matrix) compared to a high-phytate meal (inhibitory food matrix). As a secondary endpoint, we will investigate the RBV of native or fortification iron in non-inhibitory or inhibitory meals after addition of edible house crickets.

Edible insects contain iron at similar concentrations as meat and is mostly organically bound. It is currently not known to what extent iron from edible insects is absorbed in humans.

Fractional iron absorption will be determined at two time points for 3 experimental meals each.

6 experimental meals consisting of maize meal porridge prepared from either refined or whole grain maize flour, enriched with intrinsically 57Fe-labelled crickets (freeze dried, grinded), with unlabelled crickets and 54Fe-labelled iron sulphate fortificant, or with 58Fe labelled iron sulphate fortificant.