Development of nutrient-rich Teff bread and its effects on iron status and exercise performance in female runners

Alaunyte, Ieva (2013) Development of nutrient-rich Teff bread and its effects on iron status and exercise performance in female runners. Doctoral thesis (PhD), Manchester Metropolitan University.

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Abstract

Public awareness of the health benefits associated with less-utilised yet nutritious grains has led to a growing demand for healthier cereal products. This has resulted in an interest in improving the nutritional properties of refined white wheat bread, which is one of the main staple foods for most Western nations. Teff is a small-grained cereal that is rich in nutrients and particularly abundant in iron. Therefore, Teff offers the potential to provide a healthier alternative bread product. Female athletes, especially runners are at risk of iron deficiency due to increased iron loss, inadequate dietary iron and limited iron bioavailability in the diet. Good nutrition has been suggested as the first line of action to prevent iron deficiency in this population. As cereals and cereal products are a main contributor to iron in the diet, the modification of dietary iron intakes through a staple food offers a good opportunity to improve the iron status of physically active females. The aims of this research project were 1) to develop a novel, iron-rich bread product by incorporating Teff grain; 2) to explore dietary iron intervention by the means of a staple food product and to measure the effects of this intervention on iron status and exercise performance in female runners. The results indicated that the addition up to 20% of Teff (flour weight) into the bread formulation significantly (P<0.05) increased dietary iron levels without detrimental effects on bread quality. By the use of enzyme combinations, this level was increased to 30%, giving a product that provides over 75% RNI for dietary iron if daily amount of 200g of bread is consumed. A cohort of 11 female runners reported inadequate daily dietary iron intake of 11 mg/day, which was associated with overall compromised iron status. A 6-week dietary intervention resulted in significantly (P<0.05) higher total iron intakes and improved iron tissue supply but not enlarged iron stores. In terms of exercise performance, there were significant (P<0.05) improvements in submaximal VO2 at anaerobic threshold and time-to-exhaustion but not maximal VO2max peak. Moreover, improvements in submaximal gas exchange parameters and endurance were significantly (P<0.05) correlated to improved iron status. It was concluded that Teff bread is a promising iron-rich staple food alternative. It offers the opportunity to improve habitual dietary iron intakes. Favourable trends were observed between improved iron intakes, iron status and exercise performance in this study. Further research is advised to determine the bioavailability of iron from Teff bread and to confirm these findings using larger groups of participants.