Haem and non-haem iron are the two types of iron found in foods. The former is found in meat and fish, while the latter is found in plant foods, such as vegetables, beans and cereals.
Inadequate iron intake can lead to iron deficiency or iron-deficiency anaemia (IDA), and is a common issue for Australian women of reproductive age.
As such, researchers in Australia conducted a study to analyse biochemical data and dietary intake in 299 generally healthy women aged 18 to 35 to determine the link between haem and non-haem iron intake and serum ferritin.
Levels of iron
They found that approximately a third of the study subjects had sub-optimal iron status. Those with iron deficiency or IDA consumed significantly lower total energy than those with a higher iron levels.
"This high prevalence of sub-optimal iron status, when compared to current estimates of 20% within the Australian population, confirms the relevance of examining this nutrient deficiency in young women," they wrote.
The researchers also observed that haem iron was a stronger predictor of serum ferritin than non-haem iron; this might have been due to haem iron being more easily absorbed by the body than non-haem iron.
They wrote: "The study demonstrates that intake of both haem iron and non-haem iron, as well as adequate dietary energy, are associated with normal iron status levels in young women, and that restrained eaters may be at greater risk of low iron status."
"It may be taken to suggest that to maintain optimal serum ferritin levels, young women in Australia should be encouraged to consume iron-rich foods and to refrain from unnecessary energy restriction, or to seek professional dietetic advice when energy is restricted, to assist in optimising intake of iron and other micronutrients".
At the same time, because haem iron is a stronger predictor of serum ferritin than non-haem iron, the researchers said sources of haem iron — especially red meat, which is more iron-rich than white meat — are important in maintaining iron status.
Still, they concluded that "further studies are needed to confirm the effect of alterations to intake of red meat on biochemically-assessed iron status".
"In the case of non-haem iron, and particularly for vegetarians who exclude haem iron sources, adequate intake of non-haem iron, and meal planning to optimise enhancers and minimise inhibitors should be considered."
"Association between Haem and Non-Haem Iron Intake and Serum Ferritin in Healthy Young Women"
Authors: Isabel Young, et al.