No, you didn’t just log on to the American Meat Institute’s web-site by mistake. The truth is, both athletic and sedentary women may be at risk for iron deficiency anemia, mainly because of their poor nutritional status. Iron deficiency anemia has been blamed as the culprit for women’s fatigue and weakness. However, most research shows that true iron deficiency anemia is rare in both athletic and non-athletic populations. Let’s learn more about anemia, some common myths and misconceptions, and some strategies to ensure that if you eat your meat, you won’t have to worry about being an anemic lazy cow.

All About Anemia
Anemia itself isn’t actually a disease, but it’s a symptom of many diseases [1]. Taber’s Medical Dictionary lists 29 different types of anemia, and looking through the literature, you could count many more [2]. Any type of anemia is characterized by a reduction in the number of red blood cells (RBCs) in the blood. The RBCs contain hemoglobin (Hb), which is the iron-containing protein that carries oxygen around the body. When the Hb levels fall below a normal range (12.0 to 16.0 g per 100 ml of blood for women), it is termed anemia [3].
Maybe you have heard women say that they are anemic or have low iron. You might have even read somewhere that women involved in endurance exercise are usually anemic. Well, let’s cut the fat and get right to the meat of the issue. There are significant differences between an iron deficiency, iron deficiency anemia, and the so-called “sports anemia.”

Sports Anemia
If there was an anemia you would want to have, “sports anemia” or “dilutional pseudoanemia” is the one to strive for. You’ll definitely have to work hard as an endurance athlete to achieve the maximal results of this anemia. Regular aerobic exercise increases plasma volume, which is the liquid portion of the blood. The increase in plasma volume dilutes the number of RBCs in the total Hb count, and although the Hb levels may be lower than average, the iron levels are within normal limits. This blood “thinning” is the beneficial effect of hard training. It delivers more oxygen to working muscles, makes blood flow easier and clot less, and can help prevent heart attacks and strokes [4]. There is evidence from some studies that suggests even moderate aerobic exercisers will have slightly lower Hb concentrations and may enjoy the benefits of “sports anemia” [5].

Ironing Out the Deficiencies
There are significant differences between iron depletion, iron deficiency, and iron deficient anemia. Iron stores in the body are measured by serum ferritin levels. If serum ferritin levels are low, iron stores are depleted. If the stores continue to drop, an iron deficiency develops. True iron deficiency anemia results from a low Hb concentration as well as a low serum ferritin level. Research has shown that although women do have iron deficiencies, the prevalence was just as high between athletes and non-athletes, and the deficiency had little effect on performance or mood [6]. But if the iron deficiency progresses into a true iron deficiency anemia, it could have detrimental effects on work capacity and oxygen and carbon dioxide transport, and contribute to fatigue, weakness, and dizziness [7]. Even mild iron deficiency anemia adversely affects athletic performance [8].
So what about everything you’ve heard regarding women and low iron status? Well, it’s probably all true. Women typically eat a carbohydrate-heavy diet where the source of iron comes from breads and cereals (non-heme iron) as opposed to red meats (heme iron). One study described the relationship between dietary iron intake in male and female endurance-trained athletes and a control group of non-exercisers. The researchers found that while all of the men met the USRDA for iron intake, neither the female athletes nor the sedentary control group consumed nutritionally adequate diets for iron [9]. They conjectured that a focus on consuming vegetarian-type diets that contained non-heme-iron jeopardized iron status.

Causes of Iron Deficiency
Many factors and combinations of factors have been mentioned in the scientific literature that decrease iron stores. For endurance athletes, suggested losses of iron can come from gastrointestinal bleeding, hematuria (blood in the urine), excessive sweat, and high intensity, excessive exercise [7]. These losses, however, are seen as negligible, or correctable [4, 10, Chatard, 1999 #24]. Many athletes put themselves at risk for an iron deficiency by not consuming enough calories. Vegetarian diets present a challenge to achieving the necessary amount of iron. Of course, iron loss occurs during menses, also. But the primary cause of iron deficiency in all women (athletic and sedentary) is the lack of iron in their diet [4].

Have a Steak or Two
What’s a girl to do except eat a steak or two? As with most medical problems, the key to solving them lies in prevention. First, having an annual check-up and blood test will determine if you need to worry at all. If an iron deficiency or iron deficiency anemia is found, your doctor should determine the cause. Excessive menstrual blood loss can be determined, and if bloody stools are present, or you are older than 40, a gastrointestinal evaluation can be performed [2]. Aside from medical disorders, dietary iron deficiency and iron deficiency anemia treatment and prevention includes eating a balanced diet that contains the recommended amount of calories and iron. The current USRDA for iron is 15-18 mg/day for women [11]. The best sources of iron come from red and organ meats and dark chicken meat. Additional sources of iron come from fish, clams, oysters, dried legumes, soy, nuts and seeds, iron enriched or fortified breads and cereals, and dark, green leafy vegetables. Although getting enough iron in the diet is the best way to go, your doctor may suggest iron supplementation. But, try the steak first! The American Meat Institute would be proud of you.

References
1. Thomas, C.L., ed. Taber's cyclopedic medical dictionary. 18 ed. Began in 1940. 1997, F.A. Davis Co.: Philadelphia. xxiv, 2439.
2. Nichols, A.W., Nonorthopaedic problems in the aquatic athlete. Clin Sports Med, 1999. 18(2): p. 395-411.
3. Gledhill, N., D. Warburton, and V. Jamnik, Haemoglobin, blood volume, cardiac function, and aerobic power. Can J Appl Physiol, 1999. 24(1): p. 54-65.
4. Eichner, E.R., Sports anemia, iron supplements, and blood doping [see comments]. Med Sci Sports Exerc, 1992. 24(9 Suppl): p. S315-S318.
5. Eichner, E.R., Antithrombotic effects of exercise. Am Fam Physician, 1987. 36(5): p. 207-11.
6. Risser, W.L., et al., Iron deficiency in female athletes: its prevalence and impact on performance. Med Sci Sports Exerc, 1988. 20(2): p. 116-121.
7. Chatard, J.C., et al., Anaemia and iron deficiency in athletes. Practical recommendations for treatment. Sports Med, 1999. 27(4): p. 229-240.
8. Schoene, R.B., et al., Iron repletion decreases maximal exercise lactate concentrations in female athletes with minimal iron-deficiency anemia. J Lab Clin Med, 1983. 102(2): p. 306-312.
9. Weight, L.M., P. Jacobs, and T.D. Noakes, Dietary iron deficiency and sports anaemia. Br J Nutr, 1992. 68(1): p. 253-260.
10. Nachtigall, D., et al., Iron deficiency in distance runners. A reinvestigation using Fe- labelling and non-invasive liver iron quantification. Int J Sports Med, 1996. 17(7): p. 473-479.
11. National Research Council (U.S.). Subcommittee on the Tenth Edition of the RDAs., National Institutes of Health (U.S.)., and National Research Council (U.S.). Committee on Dietary Allowances., Recommended dietary allowances. 10th ed. 1989, Washington, D.C.: National Academy Press. x, 284.