While medical practice generally turns a blind eye to the value of nutrition in health, it has at least embraced the importance of certain specific nutrients, including iron. Iron is important for the manufacture of hemoglobin—the protein in the red blood cells responsible for carrying oxygen around the body and delivering it to the tissues. Iron deficiency can lead to anemia, which can lead to symptoms including fatigue and low mood.
What is less well recognized about iron is that it participates in the reactions that generate energy within the body. It is possible for individuals to become iron deficient without becoming anemic. However, iron deficiency in the absence of anemia can still cause individuals to suffer symptoms such as fatigue and low mood. This is particularly common in women of childbearing age, especially as a result of loss of iron via menstrual bleeding each month.
The relationship between iron status, anemia, and mental function was recently studied in a group of 149 women aged 18–35 years. [1] At the beginning of the study, women were classified as being either iron-sufficient, iron-deficient and anemic, or iron-deficient in the absence of anemia. All women were put through their paces with eight tests of mental function.
At the beginning of the study, the iron-sufficient women performed better and completed the mental tasks more quickly than the iron-deficient anemic women. Cognitive performance and task completion results among the iron-deficient non-anemic women fell between the iron-sufficient women and iron-deficient anemic women.
In my experience, the best test for iron levels in the body is is serum ferritin. It is my experience that ferritin levels of less than about 50 ng/ml are generally associated with symptoms such as fatigue, low mental energy, and low mood. As I said, women of child-rearing age are at risk of this. This is particularly true for vegetarians and vegans.
In the study, women who were iron-deficient were then treated with iron supplements for a period of eight weeks. At the end of the study, a significant improvement in serum ferritin was associated with a five- to seven-fold improvement in mental function. The authors of this study concluded, "Iron status is a significant factor in cognitive performance in women of reproductive age." They went on to add "…the severity of iron deficiency affects accuracy of cognitive function over a broad range of tasks."
In medicine, we commonly check for anemia. However, we much less commonly check for iron status. I do think it is important for individuals to be alert to the fact that iron deficiency in the absence of anemia has adverse effects on health and wellbeing.
Those not wishing to stoke up on liver and red meat may wish to contemplate supplementation.
References:
1. Murray-Kolb LE, et al. Iron treatment normalizes cognitive functioning in young women American Journal of Clinical Nutrition, 2007; 85(3): 778-787
Dr John Briffa is a London-based doctor, author, and health writer with an interest in nutrition and natural medicine.
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