Stamp out Iron deficiency

By Glen McGowean

Every living cell, whether plant or animal, contains iron. Most of the iron in the body is a component of two proteins: Hemoglobin in red blood cells and myoglobin in muscle. Hemoglobin in the blood carries oxygen from the lungs to tissues throughout the body. Myoglobin carries and stores oxygen for the muscles. Both contain iron, which helps them hold and carry oxygen and then release it.
Endurance athletes, and especially women athletes, are prone to iron deficiency. Physical activity may impair iron status in several ways. For one, iron may be excreted in sweat. For another, iron may be lost through red blood cell destruction; Blood cells are squashed when body tissue (such as the soles of the feet) make high impact contact with an unyielding surface (such as the ground). This condition is referred to as “footstrike hemolysis” or red blood cell destruction via foot strike. In addition, physical activity may cause small blood losses through the digestive tract, at least in some athletes.
Perhaps more significant that losses are the high iron demands by muscle to make the iron-containing molecules of aerobic metabolism. Habitual low intakes of iron-rich foods as well as increased losses and extra demands may contribute to iron deficiency in athletes. Vegetarian women athletes may be especially vulnerable to iron insufficiency.

Iron deficiency and anemia are not one and the same, though they often occur together. The distinction between iron deficiency and iron deficiency anemia is a matter of degree. People may be iron deficient, meaning that they have depleted iron stores without being anemic, or they might be iron deficient and anemic. With regard to iron, the term anemia refers to severe depletion of iron stores resulting in low blood hemoglobin.

Iron deficiency impairs performance because iron helps deliver the muscles’ oxygen. Insufficient oxygen delivery reduces aerobic work capacity, so the person tires easily.
Early in training, athletes may develop low blood hemoglobin for a while. This condition, sometimes called “sports anemia,” probably reflects a normal adaptation to physical activity.

In the first stages of iron deficiency, the athlete’s performance begins to decline. The athlete may complain of burning thighs and nausea from becoming anaerobic.
An athlete suffering from this deficiency may lack “get up and go”. Tiredness, apathy and a tendency to feel cold all reflect the energy deficiency of iron deficiency anemia.

The body has special provisions for obtaining iron. Normally, only about 10 to 15 percent of dietary iron is absorbed; but if the body’s supply of iron is diminished or if the need increases for any reason, absorption increases.

Iron recommendations and sources

Men need 10 milligrams of iron each day and so do women past the age of 51. For women of childbearing age, the recommendation is 15 milligrams per day to replace menstrual losses. During pregnancy, a woman’s needs double this amount, or 30 milligrams per day.

To meet iron needs, it is best to rely on foods because the iron from supplements is much less well absorbed than from food.

Iron occurs in two forms in foods. Heme found in meat, poultry and fish and non-heme found in foods from plants and found in some meat sources. The form affects absorption.

Absorbing iron

Heme iron is much more readily absorbed than is non-heme iron. Healthy people with adequate iron stores absorb heme-iron at a rate of about 23 percent over a wide range of meat intakes. People absorb non-heme iron at rates of 2-20 percent, depending on dietary factors and iron stores.
Meat, fish and poultry contain a factor (MFP factor) other than heme that promotes the absorption of non-heme iron from other foods eaten with it. Vitamin C is also a potent promoter of iron absorption and can triple non-heme absorption fro foods eaten in the same meal.

Some factors impair iron absorption. These include tea, coffee, the calcium and phosphorus in milk and the phytates and tannins that accompany fiber in whole grain cereals. Ordinary black tea is so efficient at reducing absorption of iron that clinical dietitians advise people with iron overload to drink it with their meals. For those who need more, the opposite applies.
The amount of iron ultimately absorbed from a meal depends on the interaction between promoters of iron absorption and inhibitors.
When you eat a meal with legumes (for example, ham and beans or chili with beans and meat) MFP factor enhances the absorption from both. The vitamin C from a slice of tomato and a leaf of lettuce in a sandwich will enhance iron absorption from the bread. The meat and tomato in spaghetti sauce help the eater absorb the iron from the spaghetti. Anything cooked in an iron pan will draw iron from this source, too. For example; The iron contents in 100 grams of spaghetti sauce simmered in a glass dish is 3 milligrams, but it is 87 milligrams when the sauce is cooked in a black iron skillet.
Even in the short time it takes to scramble eggs, a cook can triple the eggs’ iron content by scrambling them in an iron pan.

Foods that provide 10 percent or more of the iron daily value:

Swiss chard (cooked) ½ cup = 2 mg (11% DV)
Navy beans (cooked) ½ cup = 2.3 mg (13% DV)
Spinach (cooked) ½ cup = 2.4 mg (13% DV)
Beef steak 3 oz = 2.9 mg (16% DV)
Enriched cereal ¾ cup = 3.7 mg (21% DV)
Tofu ½ cup = 6.6 mg (37% DV)
Clams (steamed) 3 oz = 23.8 mg (132% DV)

Toxicity

Iron is toxic in large amounts, and once inside the body, it is difficult to excrete. If toxicity were to occur, the body’s intestinal cells traps some of the iron and holds it within their boundaries. When the cells are shed (a normal function of the intestinal cells) these cells carry out the excess iron that they collected. Iron toxicity can be fatal especially in children. If you are feeling tired, do not automatically reach for an iron supplement. If you are taking them keep them out of reach of children.

Try partnering these foods up:

  • Sirloin strips with spinach salad
  • Barbecued beef with refried beans and tortillas
  • Ground beef with whole-grain roll
  • Pork with bean soup
  • Chicken with brown rice
  • Ham with scrambled eggs
  • Grapefruit with bran cereal
  • Strawberries with oatmeal
  • Red bell peppers with whole grain pasta
  • Papaya with whole wheat toast
  • Orange with peanut butter sandwich/whole wheat

If you think you may have a deficiency in iron, check with a doctor. A simple blood draw can detect a below average range.

Before starting any new program, always consult with a Doctor.

Eat well, train safe and have fun.