Submitted Aug 22, 2003   Updated Sep 26, 2010
By Ray


What is anemia?

Anemia is a process, not a disease, and is the most common disorder of the blood. Anemia occurs when the amount of red blood cells or hemoglobin (oxygen-carrying protein in the blood) in the blood becomes low, causing the tissues of the body to be deprived of oxygen-rich blood. It is characterized by a reduction in size, number, or color of red blood cells (RBC), which results in reduced oxygen-carrying capacity of the blood. The blood of an anemic person has trouble carrying oxygen to tissues and organs, in a sense, become "starved" of oxygen and without oxygen, the tissues cannot produce energy to function. In order for the body to stay healthy, organs and tissues need a steady supply of oxygen.

As a car has trouble in high altitude because there is not enough oxygen to burn the fuel; we also have difficulty without enough oxygen. A lack of proper oxygen supply can come from a number of different situations. A person might have trouble breathing in high altitude where air pressure and oxygen concentration is lower. This leads to the fact that people have trouble high on Mount Everest without extra oxygen.

A similar problem can occur when people are near sea level if the lungs are not working properly. Even though there is enough oxygen around, people might gasp for breath if they have asthma, emphysema, or other lung disease that partly blocks their ability to absorb the oxygen from the air.

The problem that we look at today is that of anemia.

Within each red blood cell are proteins called hemoglobin and embedded in each hemoglobin protein are four iron particles. These iron particles give the red blood cell the ability to transport oxygen. Iron binds to oxygen in the lungs and then circulates the oxygen-rich blood to the tissues of the body. Inadequate iron availability results in reduced production of red blood cells. And the red blood cells that do form are small, with less hemoglobin and a decreased oxygen-carrying capacity.

When the hemoglobin supply is limited; we run into a similar problem as when a person reaches high altitude or has lung disease. For even though there is enough oxygen in the surrounding air and even though a person might have good lung function, they might feel short of breath. This is because the body is still not receiving enough oxygen from the red blood cells.

What are some symptoms of anemia?


If we were in the desert and needed water to drink, we might not be satisfied if we were to receive one cup of water every day, even if each cup were very full. So even if each red blood cell does its job; if there are not enough red blood cells, then a person may be left without enough oxygen.

Having said this, is becomes easier to understand what some of the symptoms of anemia might be: feeling short of breath when exercising, or just feeling tired all the time, having a lack of energy, and fatigue. These may simply be indicators that the body is not getting enough oxygen.

Are children affected?


Iron deficiency is one of the most prevalent nutritional problems of children in the United States. Iron deficiency in infancy may cause a permanent loss of IQ later in life. Iron deficiency and anemia lead to shortened attention span, irritability, fatigue, and difficulty with concentration. Consequently, anemic children tend to do poorly on vocabulary, reading, and other tests (Parker, 1989).

Strong evidence exists that nutrition-related disorders are greater among low-income households than among the rest of the population. Growth retardation, which may reflect dietary inadequacy, occurs in preschool children from low-income families at up to three times the rate as in their nonpoor peers. Iron deficiency anemia is twice as common in poor children between ages 1 and 2 than it is in the general population (Parker, 1989).

Can anemia be dangerous?


Mild anemia does not have any significant long-term consequences. However, as the anemia becomes more severe, there are medical problems, which may arise. One of the most serious of these involves the heart. Severe anemia may cause a condition called high-output heart failure, where the heart must work harder to provide enough oxygen to the brain and other internal organs. The heart beats faster and increases the amount of blood that is delivered per minute. When this condition occurs in individuals that have existing heart disease, the heart may be unable to keep up with this increased demand, and symptoms of heart failure such as difficulty breathing and leg swelling may occur. Individuals who have coronary artery disease, or narrowing of the blood vessels supplying blood to the heart, may develop symptoms of angina, the pain associated with an insufficient blood flow to the heart muscle. Depending on the age of the person and the degree of coronary artery disease, angina may develop with even mild anemia. In severe cases, the heart muscle may be permanently injured.


What causes anemia?


Anemia can be caused by not enough red blood cells being produced; by too many red blood cells being taken out of circulation or destroyed. This loss of circulating red blood cells can be due simply to bleeding or it might be related to the red blood cells' not surviving as long as they were designed to survive.

Let's first look at not enough red blood cells being produced.

This occurs when the machinery or the raw materials for red blood cell construction are not available. If we were making wheat flour, we would want wheat kernels and also a machine to grind the kernels. If either were missing, we would not get the wheat flour. For red blood cells to be produced properly we need the raw materials of the red blood cell and we need the machinery to put these materials together into blood cells. One of the key raw materials used in producing red blood cells is iron. Iron is an important component of the hemoglobin molecule. And when significant bleeding occurs over a period of time, one of the complications is loss of iron. People commonly become iron deficient from loss of blood over a long period of time.

What are sources of iron from plant foods?

Drs. Agatha and Calvin Thrash have a useful book on vegetarian nutrition. Some good sources include: green leafy vegetables, legumes, prunes, dried apricots, raisins, nuts, and whole grains.

So iron is a raw material used in production of hemoglobin.

Yes, this is important in the production of hemoglobin. Iron-rich plant foods include green leafy, vegetables, and iron-fortified cereals. Meats although rich in iron are better avoided due to problems with fat, disease, and other harmful chemicals.

The total amount of iron in the body is dependent on intake, loss, and storage of the mineral.

Can a person have too much iron in the body?

Yes, too much iron may play a role in heart disease; in 1992, Scandinavian researchers surprised many in the medical community with the discovery that higher amounts of iron stored in the body increased a person’s risk of heart disease.

If a person has dramatically excess of stored iron in the body, he might develop liver problems, diabetes, or other problem.

A dissertation from UCLA suggests that the risk of colon polyps and thus colon cancer is increased by either excessively low or excessively high levels of iron.

Harvard researchers analyzed the dietary habits of nearly 45,000 men and then kept in touch with them for four years. They found that the men who ate the largest amount of animal sources of iron (called "heme" iron) had higher rates of heart attacks. This relationship could not be explained by differences in the amount of fat or cholesterol they were eating. Those same men with liberal intakes of iron from animal sources also had higher serum ferritin levels, meaning that they had more iron stored in their bodies.

Plant foods provide iron in amounts that are generally adequate—but not excessive. A 1996 article summarized some of the problems with excessive amounts of iron as it relates to cancer risk:

        1. It favors the formation of compounds called hydroxyl radicals which have the potential to damage DNA.

        2. It suppresses the activity of host defense cells.

        3. It promotes cancer cell multiplication.

Dr. E. D. Weinberg, the study’s author concluded: "Procedures associated with lowering...iron intake can assist in prevention and management of neoplastic diseases [cancer]."

How does a person lose iron from the body?

The most common type of anemia is iron-deficiency anemia. Just as the name implies, this form of anemia is due to insufficient iron. Recently in the United States, about 20% of all women of childbearing age have iron-deficiency anemia, compared with only 2% of adult men. The principal cause of iron-deficiency anemia in premenopausal women is blood lost during menses.

During their reproductive years, women are at an increased risk for iron deficiency because they lose 20-40 mg or iron per month during the menstrual cycle. Inadequate iron needs to be replenished through a well balanced diet. Iron balance is maintained through the absorption mechanism of the gastrointestinal tract. 

In older people bleeding might occur in the colon such as from colon cancer, or perhaps for ulcers to cause bleeding in the upper part of our digestive system. This upper intestinal bleeding is often related to drugs called NSAIDS.

Can you name some of the NSAIDS that might do this?


Aspirin, naproxen/Naprosyn/Alleve, ibuprofen/Advil, indomethacin, and others.

So some of these medications don't even require a prescription.


That is true. And we need to be alert that even nonprescription medication can sometimes be quite damaging.

You mentioned that colon cancer can cause anemia, if my doctor tells me that I have anemia, does this mean that I have colon cancer?


No, my guess is that if your doctor tells you that you have anemia, you are not likely to have colon cancer. But if you do not know the cause of your anemia, then ask your doctor. If you are over 40 to 50 years old and if your doctor is not sure about the cause, then ask him or her if you should have your colon checked to see if colon cancer might be present.

Tell us about the machinery that makes the red blood cells.


The bone marrow makes the red blood cells. Sometimes when a person has damage to the bone marrow, anemia can develop. This can occur from radiation for cancer or from the marrow becoming diseased by other processes. If the body does not produce enough red blood cells to keep up with the loss from old red blood cells and bleeding, then anemia results.

If red blood cells don't last as long and this can also cause anemia.


When the spleen becomes too large from another disease process, then it may take out more red blood cells than usual resulting in too few red blood cells in the circulation. While the average red blood cell lives about 120 days, some processes can occur to shorten the life of these cells. Sometimes people have problems with the red blood cells bursting before they are supposed to. An example of this would be yellow baby syndrome.

Perhaps our listeners have heard about hemolytic disease of the newborn or yellow baby syndrome. Sometimes the mother has certain antibodies in her circulation that lead to destruction of the baby's red blood cells. This may cause anemia in the baby and the breakdown of the red blood cells can make the baby turn yellow.

Severe infection can sometimes cause the red blood cells to be destroyed.

People who have abnormal red blood cells may have a shorter life span of the red blood cells.

Sickle cell disease can cause the hemoglobin to take a very abnormal form, and the red blood cell can be destroyed.



Red blood cells tend to be small in iron deficiency anemia; are they small in all anemias?


No, other common nutritional anemias include folate and Vitamin B12 deficiencies.

In these types of anemias, the red blood cells tend to be large than normal. If you eat a lot of fruits, whole grain products, and vegetables that are not highly processed, then you probably get enough folate. Eating fruits, dark-green leafy vegetables, dried beans and peas, and other foods should be helpful.

Vitamin B12, though is a more difficult substance to obtain if we eat a completely plant-based diet. While dairy products, meat and eggs supply sources of this vitamin; these are probably not the safest way to obtain vitamin B12. The fat, cholesterol, and often-found diseases associated with these products limit their usefulness.

A better approach might be to consider a vitamin B12 supplement. These supplements are widely available. It is probably a good idea to use a maintenance dose close to the RDA even though some supplements might offer multiple times this amount in one pill.


What are sources of Folate?


Folate is quite easy to obtain in good amounts from plant sources: fresh orange juice, peanuts, mustard greens, spinach, navy beans, okra, lentils, black-eyed cowpeas.

Fresh green vegetables and certain fresh fruits will provide adequate folate intake.

Does folate help with heart disease also?


Yes, it appears that folate in fruits and vegetables solely may reduce the risk of heart attack and stroke probably at least part of the mechanism relates to lowering homocysteine levels.