Iron deficiency may impair cognitive function

Women of Iron

Women have a greater tendency than men to be iron deficient. But that’s not news.

And when an iron deficiency is pronounced enough to cause anemia, cognitive function may become impaired. That’s not news either. (In 2001, a Greek study of subjects over the age of 65 demonstrated that anemia is a risk factor for cognitive impairment.)

But a new study reveals that a mild iron deficiency – well short of anemia – may be all that’s needed to impair cognitive function.

Unfortunately, the study also suggests that an iron supplement will turn things around. But there’s more to iron sufficiency that simply loading up on iron. In fact, too much of the wrong kind of iron can do more harm than good.

Testing 1, 2, 3

The new study comes from Pennsylvania State University, where researchers recruited 113 women, aged 18 to 35. At the outset of the study, a round of cognitive abilities tests were administered. In addition, blood samples separated the women into three categories: 30 were iron sufficient, 53 were iron deficient, and 30 were iron deficient anemic.

In the initial tests, women who were iron deficient (but not anemic) scored significantly worse than women who were iron sufficient. Women with anemia also scored worse, but took longer to complete the tests. And in general, the worse the anemia, the longer they took.

In the four months following the first tests, the women were randomly selected to receive either a 60 mg iron supplement daily, or a placebo. At the end of this period, the subjects took another round of tests. On average, the women who took the supplements (regardless of their previous iron status) scored just as well on the tests, and just as quickly, as the women who were iron sufficient at the outset of the study.

The authors of the study concluded that their research demonstrates “that iron status is related to information processing in adult women.”

Simple, right? Keep that iron level high, and you’ll keep cognitive abilities sharp. But there’s something potentially wrong with this picture.

Just add iron?

The problem with the Penn State research is also the key to its success: iron supplements. These supplements may have done wonders in the short run, but as an ongoing therapy, iron supplementation has some pitfalls.

As long-time e-Alert readers know, HSI Panelist Allan Spreen, M.D., is an advocate of vitamin dosages well above the recommended daily allowance (RDA) for most supplements. But not for iron, which can create problems in high doses. Dr. Spreen says, “The RDA of iron is far too high. Plus, even if you were proven to have anemia, I wouldn’t treat it with inorganic iron. The mineral is too reactive in the body when it is not insulated from the system by being encased within the heme structure of hemoglobin. Free radical formation from free iron is just too much of a threat.”

Dietary sources of heme iron come exclusively from red meat, fish, pork, and poultry, with beef liver and chicken liver having the highest amounts of iron. An additional intake of vitamin C can also help the body absorb iron.

Check with your doctor

The two primary causes of anemia are iron-poor blood (often triggered by menstruation or internal bleeding), and a deficiency in two critical vitamins: folic acid and vitamin B-12. Getting good amounts of these nutrients is especially important for seniors because as we age our ability to absorb vitamins from food diminishes. Consequently, our tendency to develop anemia rises.

Unfortunately, many mainstream doctors see so many elderly patients who have anemia that the condition is widely regarded as a normal part of aging. As a result, when anemia is diagnosed it often goes untreated. This is a critical mistake because in recent years, research has shown that anemia dramatically increases the risk of mortality for those with chronic health problems such as heart disease. At the same time, anemia can also promote cancer, which thrives in a cellular environment that’s starved of oxygen.

Anemia is easily diagnosed with a typical blood test, so ask your doctor to check your next blood test for a reading of your red cell blood count – especially if you’re feeling unusually fatigued. If you do have an anemic condition, the next step is to find out the cause. But if your doctor downplays anemia’s importance, or if he recommends a prescription drug, seek a second opinion from a doctor who’s knowledgeable about the nutritional problems that can cause an anemic condition.

“Iron Status Alters Cognitive Functioning in Women During Reproductive Years” Experimental Biology 2004, Abstract #3128, April 2004,
“Moderate Iron Deficiency Affects Cognitive Performance – But Iron Supplementation Improves it” Federation of American Societies for Experimental Biology, 4/19/04,
“Distracted Young Women May Need More Iron” Dan Lewerenz, Associated Press, 4/28/04,
“In What Extent Anemia Coexists with Cognitive Impairment in Elderly: A Cross-Sectional Study in Greece” BioMed Central Family Practice, Vol. 2, No. 1, 2001,