Health News Update: Iron Works
Most regular exercisers think of “pumping iron” as strength training done with either free weights or machines. However, iron the mineral is so important to good health that even a minor deficiency can affect muscular strength as well as aerobic capacity and muscle endurance.
According to Cheryle Baldwin, Ph.D. in an article published in the IDEA SOURCE (Journal for Health and Fitness Professionals): “Iron deficiency remains the most common nutrient deficiency, affecting more than 1 billion people worldwide.” Fortunately, most cases of iron deficiency are reversible through proper dietary changes.
Iron is identified as “an essential nutrient” which means the body can’t make it on its own – it must be consumed through food. Iron is stored in the body as ferritin in bone marrow, liver, and spleen and is carried throughout the blood stream to help circulate oxygen through the body, including muscles and the brain. In addition, it plays a key role in enzyme functions, energy metabolism, and may reduce the possibility of neuron damage. (Atamna et al. 2002)
Sadly, iron deficiency often goes untreated because symptoms are often attributable to other causes. Some signs and symptoms include: (Baldwin, 2003)
- Short attention span
- Inability to concentrate
- Apathy
- Shortness of breath
- Fatigue and tiredness
- Difficulty maintaining body temperature
- Heart beat changes
- Impaired learning ability
In my lifestyle counseling practice, I have observed that frequent headaches and heavy menstrual bleeding may also be associated with iron deficiency.
Because of the body’s constant iron expenditure, it is necessary to consume a certain amount daily. The Recommended Daily Value for healthy adults is 18 mg/day. However, this general recommendation does not take into account variability in iron absorption or utilization. For example, the recommendation for the over 50 population is 8 mg/day.
Iron comes in two forms: heme iron from meat, fish, and poultry sources, which is well absorbed, and non-heme iron from vegetarian sources, which is less well absorbed. Non-heme iron absorption is enhanced by adequate intake of Vitamins A & C, zinc and iodine and inhibited by calcium and caffeine, and polyphenals found in tea. Therefore, it’s a good idea to consume your caffeine, calcium and tea separately from your iron sources.
Best non-heme sources include red kidney beans (5.2 mg/serving), raisins (1 cup) (3 mg) and potato with skin (2.7mg), and dark leafy greens like broccoli and spinach. Enjoy a delicious red bell pepper or Vitamin C rich citrus fruit with these sources to enhance absorption. Heme sources include: pork (3 oz loin chop – 3.5 mg) and steak (3 oz – 2.6 mg), ground beef (3 oz – 2.2 mg).
Who’s at risk? Vegetarians, children and adolescents, women of child-bearing age, pregnant women (who need 27 mg/day!), as well as athletes and regular exercisers. However, even if you belong to one or more of these categories, do not run out to buy an iron supplement unless you have an iron deficiency confirmed by blood work. Excess iron is toxic in does higher than 75 mg (keep iron supplements out of the reach of children!!) and has been associated with reduced zinc absorption, gastro-intestinal discomfort and constipation.
In addition, there are approximately one million in the US who suffer from iron overload according to the Center for Disease Control. This is caused by over-absorption of iron and can be detected through blood testing. This condition is most often seen in people with a condition called hereditary hemochromatosis. Besides fatigue, symptoms may include unexplained joint or abdominal pain, liver disease, diabetes, heart problems, impotence, infertility, and cessation of menstrual periods. Untreated, this can result in arthritis, diabetes, heart disease, liver disease, and cancer. (Baldwin, 2003)
Furthermore, recent studies have associated excess iron consumption with the oxidation of cholesterol and damage to the arterial walls.
A well-balanced diet and a well-balanced workout go hand in hand. So, if you want to get the most from your exercise, be sure to pay attention to your iron intake. Popeye may have been on to something when he recommended eating that spinach!!