It is highly likely that someone you know has low iron levels and for this reason I think the subject deserves a look. This informative post provides a brief overview of the role of iron, deficiency, food sources and requirements.
Theoretically, to boost our iron levels we could have an iron rich cereal for breakfast with a glass of orange juice. For dinner a serving of red meat with a baby spinach and red capsicum salad would be optimal. Realistically, we may have the cereal for breakfast but it’s followed by a nice strong coffee. Our red meat at dinner may be accompanied by a glass of red wine. This combination however does not help our iron stores due to presence of inhibitors such as polyphenols. Poly-what you’re thinking…don’t fret…all is explained after this random, yet related picture 😉
What is the role of iron in the body?
Iron is part of many proteins in the body including haemoglobin in red blood cells which is important in transporting oxygen around the body. It is also associated with many enzymes and reactions within the body.
What are the stages of deficiency?
The term ‘anaemic’ is used by many people but in fact they may be referring to one of the earlier stages of deficiency. The overlapping continuum starts with depletion in iron stores (iron depletion), followed by early iron deficiency and lastly a reduction in haemoglobin (iron deficiency anaemia).
Who is at risk?
Toddlers, children, teenage girls, fad dieters, athletes, vegetarians, pregnant women…just to name a few of many.
What causes a deficiency in iron?
There are various possible contributing factors including (but far from limited to):
- Menstrual blood losses
- Frequent endurance exercise
- Increased turnover of iron containing red blood cells and loss of iron in sweat (small amount)
- Inadequate iron intake in foods
- Low bioavailability (low amount of iron available to the body)
- Calcium, zinc, phytates (found in legumes, rice and other grains) inhibit absorption of both forms of iron: haem and non-haem iron
- Polyphenols (found in tea, coffee, red wine and cocoa) inhibit the absorption of non-haem iron
- Limited intake of haem iron
Inadequate absorption of iron and increased blood losses can also contribute to a deficiency in iron (but is beyond the scope of this relatively brief post).
What is haem and non-haem iron?
Haem iron is only found in animal sources and has a considerably higher absorption than non-haem iron. Non-haem iron is found in both plant and animal sources.
What foods contain iron?
Source: NUTTAB 2010
Source: NUTTAB 2010
Don’t get too excited by those figures for non-haem sources and start eating a Popeye inspired diet. Remember that haem iron is absorbed considerably more than non-haem iron. The absorption of non-haem iron can be improved though by consuming iron absorption enhancers such as vitamin C rich foods and/or haem iron containing foods with non-haem iron foods.
How much iron do I need?
Iron requirements vary greatly across the lifespan due to factors such as growth, menstruation and increased blood volume during pregnancy. On average, adult men need to absorb about 1 mg/day and adult females about 1.5 mg/day of iron. It doesn’t sound like much when looking at the above figures but as mentioned previously the absorption of iron is rather low and therefore we need to consume a much greater amount. Females generally require considerably more iron than males and it is important that you choose foods that help you reach your Recommended Dietary Intake (RDI) of iron. The below RDIs are based on the absorption level of iron from a Western diet (that is including both meat and plant foods).
Source: NHMRC Nutrient Reference Values for Australia and New Zealand 2006
National Health and Medical Research Council (NHMRC)
Dietitians Association of Australia (DAA)
Australian Institute of Sport (AIS)
NUTTAB 2010, Food Standards Australia New Zealand (FSANZ)