The effect of a meat extract on iron absorption in young women : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Human Nutrition at Massey University, Palmerston North Campus, New Zealand

Abstract

Iron deficiency is a global problem for which determinants and solutions need to be investigated. The first part of this study assessed the iron status and dietary intakes of 85 non vegetarian women aged 18-40 years living in the Manawatu region. Exclusion criteria included pregnancy or breastfeeding in the past 12 months, smoking, excess alcohol consumption and recent blood donation. Dietary intakes were estimated using a 24 hour recall and a non validated food frequency questionnaire. Serum ferritin (SF), haemoglobin (Hb), C-reactive protein, height, weight and supplement use were measured. Two women (2.4%) had iron deficiency anaemia (SF20µg/L). The daily mean and median iron intakes were 12.7±6.2mg and 10.8mg. 71 women (83.5%) consumed less than the Recommended Dietary Intake (RDI) of 18mg iron per day and 21.2% consumed less than the Estimated Average Requirement (EAR) of 8mg iron per day. Serum ferritin was positively associated with age and total dietary iron intake. No statistically significant relationship was found between serum ferritin and Body Mass Index or exercise, or daily intakes of energy, protein, haem iron, red meat, total meat, vitamin C, vitamin A, total tea, coffee, alcohol, fibre or calcium (p>.05). Eighteen women who had low iron stores (SF<30µg/L) were selected to take part in a second study to investigate the effect of a meat extract (<0.5kDa sarcoplasmic fraction) on non haem iron absorption. Each subject consumed a sodium caseinate meal, a meat meal or a sodium caseinate meal containing the meat extract. Each meal was labeled with 8.5mg 57 Fe and each subject received 0.5mg 58 Fe administered by intravenous infusion. Fourteen days later iron absorption from these meals was determined using ratios of stable isotopes of iron incorporated into the red blood cells. Iron status was significantly inversely related to iron absorption. After adjusting to a serum ferritin of 40µ/L, iron absorption was 3.8% from the sodium caseinate meal, 3.9% from the meat meal and 5.1% from the meal containing the meat extract. These values were not significantly different from one another (p>.05)