Contribution of fonio to iron and zinc intake in West Africa

With the increasing nutrition and health problems related to the global food crises, the potential contribution of traditional foods to alleviate poverty, nutritional deficiencies and health issues has been emphasized. Fonio (Digitaria exilis) is the most ancient West African cereal representing a key crop in food supply during crop shortfall periods.

Less is known about the potential of fonio to contribute to nutrition and health in West Africa. The value chain approach for nutritional goals is a set of strategies through which values are added to products for improvement of nutrition among vulnerable groups.  In this project we explored value chain strategies as possible solutions to existing nutritional problems amongst West African women, using fonio as product. To achieve this objective, specific research questions were investigated through cross-sectional studies among women of reproductive age from Bamako, Mali and from Cotonou, Benin:

  • Baseline assessment of nutrition (iron) status, iron intake and adequacy to define the nutritional context of the project. Results indicated that overweight/obesity prevalence was 19%, and 25% of women were iron-deficient. 46% and 53% of women were at risk of inadequate iron and overall micronutrient intake. Intakes of grains, vegetables and legumes/nuts were significantly associated with iron intake. Fonio was consumed by 68% of urban Malian women in low portion sizes (152g/day) contributing to 16% of daily energy intake.
  • Evaluation of reliability of the Mali food composition table. To convert food to nutrient intake, food composition databases are needed. We evaluated whether the used FCT  is acceptable for assessing average energy and nutrient intakes and for assessing probability of adequacy of intakes for selected micronutrients at population level by comparing  the nutrient intake calculated from a one day food weighed record with  that based on chemical analysis of duplicate portions of diets of the same day. The results indicated that the use of the adjusted TACAM seems acceptable for estimating average intake at population level for macronutrients, calcium and zinc in a low intake population, but not for carbohydrate and iron intakes (being underestimated), and vitamin A (being overestimated), nor for probability of adequate intakes and nutrient densities.
  • Assessing the socio-cultural acceptability of fonio as entry point for consumer-based strategies revealed that fonio consumption was strongly predicted by intenition to consume, which was influenced by positive beliefs and attributes. Subjective norms, namely the opinion of husbands, the family and the neighbourhood motivated intention to consume fonio. Perceived barriers such as time consuming processing and lack of skills in cooking fonio had a significant interaction effect between intentio to consume and fonio consumption.
  • Sensory and genetic diversity, nutrient content and effect of processing was assessed in fonio landraces collected in MAli, Guinea and Burkina Faso. Fonio landraces from Mali, Guinea and Burkina Faso show variation in visual (colour and presence of impurity) and textural characteristics (consistency of the cooked grain), determining the preference of consumers. Selecting landraces for preferred sensory properties may offer an entry point for processors who intend to promote the consumption of fonio and increase its role in diet. In absence of meaningful genetic diversity and variation in iron content in fonio landraces in Mali, there is little benefit in selecting landraces for natural high iron content.
  • Traditional processing of fonio from paddy to the mid-wet product significantly reduced the nutrient (iron) content. Although also the iron absorption inhibiting phytate was also reduced, the final molar ratio of phytate to iron stayed above the critical cut-off point of >1, suggesting  poor bioavailability of iron from fonio meals.
  • Based on the above, improving the nutrient (iron) content of fonio could therefore only be reached by reducing the phytate content of fonio coupled with increasing the iron content through fortification. dephytinisation of fonio porridges with native wheat phytase decreased phytate-to-iron molar ratio from 24:1 to 3:1 and iron fortification further reduced this ratio to 0.3:1. Results also showed that dephytinisation and fortification significantly improved iron absorption from fonio porridges from 2.6% to 8.3%.Dephytinisation using intrinsic wheat phytase could be a promising processing practice to improve iron bioavailability and fortification is required to increase the amount of absorbed iron from fonio meals.

More research: International maternal and child nutrition

More research: International nutrition