IRON

Iron has been a part of Indian kitchens since ancient civilization. The iron implements made their appearance in India between 1300-1000 BC. Soon cooking utensils made from iron were introduced.

Iron is a mineral that is required to maintain healthy blood. It is an essential component of haemoglobin (a protein in the red blood cells that carries oxygen to the different parts of the body).

We all associate iron with its presence in blood and that its deficiency results in low haemoglobin levels and hence anemia. In humans, the total quantity of iron in the body varies with haemoglobin concentration, body weight, gender, and the amount of iron stored in various tissues. About 75% of iron is present in haemoglobin, 20% is stored in the liver, spleen, kidneys, and bone marrow, and 5% is in the muscle tissue (myoglobin).

Why is iron essential for the human body?

• Iron is the main constituent of red blood cells and is present in the haem part of haemoglobin. Haemoglobin is necessary for the transport of oxygen to various parts of the body.
• It is also present in the muscle in the form of myoglobin. Myoglobin can store oxygen that is utilized for muscle contraction and other immediate needs of the muscle cells.
• The complete oxidation of carbohydrates, fats, and proteins within the cell is facilitated by iron. This results in the release of energy from the molecules. Thus, the role of iron is crucial in helping us to perform physical work. 
• Iron plays a crucial role in the maintenance of specific brain functions like immediate memory, capacity to learn, and attention span.

What is the Recommended Daily Intake (RDI) of Iron?

The Recommended Dietary Allowance (RDA) of Iron for Indians, NIN, ICMR, India is:

What are the signs and symptoms of iron deficiency?

Iron deficiency is the most common nutritional deficiency worldwide. It affects all ages, with children, women, and people with chronic diseases. The group of people who are at a higher risk of developing iron deficiency are:

– Infants and young children

– Pregnant women

– Women with heavy menstrual bleeding

– Frequent blood donors

– People suffering from cancer

– People with chronic heart disease

– People having gastrointestinal diseases.

Iron deficiency occurs in stages. The first or the mild stage occurs with a decrease in iron stores due to a low-iron diet of excessive bleeding. If this does not resolve then there is further depletion of the iron stores and a drop in the red blood cells. This leads to iron deficiency anemia (IDA). Some of the signs and symptoms of iron deficiency anemia are:

• Fatigue, weakness
• Loss of concentration
• Lightheadedness
• Rapid heartbeat
• Pale skin
• Shortness of breath
• Brittle nails
• Hair loss
• Pica: Craving for unusual things like ice, dirt, clay, chalk, etc

Iron deficiency anemia can be corrected with iron supplements and is completely reversible.

What are the different food sources of iron?

Iron is found in foods in two forms i.e., haem or non-haem. In the human diet, the primary sources of heam iron are haemoglobin and myoglobin from consumption of meat, poultry, and fish whereas non-haem iron is obtained from plant sources like cereals, pulses, legumes, fruits, and vegetables. Dietary non-haem iron accounts for about 85% of the total iron intake even among non-vegetarians. The good plant and animal food sources of iron are:

Plant sources:

Cereals – bajra, ragi, jowar, rice flakes, whole wheat flour

Pulses – Horse gram, moth beans, soybean, whole Bengal gram, rajma (red kidney beans), whole black gram, and whole brown lentil.

Vegetables – Fenugreek leaves, beet greens, Pumpkin leaves, Amaranth leaves, parsley, drumstick leaves, Colocasia leaves, and spinach leaves.

Others: Dried apricots, almonds, raisins, and seeds.

Animal Sources:

Chicken liver, beef, organ meats, tuna, chicken, eggs, salmon, and oysters.

Does excess iron in the body lead to toxicity?

In the human body, the absorption of iron is very effectively regulated. This prevents overload of the tissues with iron from diet or supplements. However, an excessive body burden of iron can be produced by greater-than-normal absorption from the alimentary canal, by parenteral injection, or by a combination of injection and oral supplements. 

In people with a genetic disorder like haemochromatosis, iron overload is likely to occur. It is a hereditary disorder of iron metabolism characterized by abnormally high iron absorption. High deposits of iron in the liver and the heart can lead to cirrhosis, hepatocellular cancer, congestive heart failure, and eventual death.

Certain inhibitors in the food like phytates and fiber from whole grain cereals, tannins, and polyphenols in tea, oxalates in green leafy vegetables like spinach, and excess calcium taken as supplements can all depress non-haem iron absorption significantly. 

The Indian vegetarian diet consisting predominantly of cereals and pulses, high in phytates, has a low iron bioavailability. This is further compromised when tea is had with a meal, as polyphenols in tea depress iron absorption. So, a wheat chapatti that has an iron bioavailability of 5%, when had in breakfast with tea the bioavailability reduces to 1.8%.

Just like there are inhibitors to reduce iron absorption, there are enhancers that improve iron absorption. Ascorbic acid or Vitamin C is a potent enhancer of iron absorption. The addition of orange juice to a breakfast meal, or adding a few drops of lemon juice to your salads, soups, and vegetables can improve iron absorption in the body.