Iron is needed for healthy blood, giving us energy and for brain development in babies. Iron is found in a number of foods, including red meat. In general, the redder the meat, the higher the iron content.
Iron is found in two forms: haem and non-haem. Haem iron is absorbed more easily by the body and is found in beef, lamb, liver, kidney, pork, poultry and seafood. Only about 5% of non-haem iron is absorbed and is found in vegetables, bread, breakfast cereals, beans, eggs and fruit.
Red meat can help to increase absorption, boosting the use of non-haem iron by up to four times. Vitamin C has a similar effect. Eating a combination of foods high in both haem and non-haem iron will ensure an iron-rich diet.
SOURCES OF HAEM IRON:
Haem iron is found only in animal products. It is easily absorbed and used by the body. About 15 – 35% of haem iron is absorbed, depending on iron stores. The body will absorb more haem iron if iron stores are low.
SOURCES OF NON-HAEM IRON:
Non-haem iron is found in both animal and plant products. It is poorly absorbed by the body (1-7 % absorption), and is not easily used. Consumption of animal proteins (meat, fish or poultry), and vitamin C can boost the absorption of non-haem iron. Tannins in tea and coffee, phytates in wholegrain cereals, oxalates in some vegetables (eg spinach) and some types of fibre can inhibit the absorption of non-haem iron.
WHAT IS IRON AND WHAT DOES IT DO?
Iron is a mineral found in some foods, which is essential for good health and for physical and mental well-being. It has three main roles:
- To carry oxygen around the body - every cell in the body needs oxygen. There is iron in the haemoglobin of red blood cells and it carries oxygen from your lungs to the rest of the body.
- Ensuring a healthy immune system - the cells that fight infection depend on adequate stores of iron. This means if your iron stores are low, your body is more prone to infections.
- Making energy - iron is essential for the body's chemical reactions that produce energy from food. Therefore, if your iron levels are low, your body may not be able to use all the energy available.
WHO IS AT RISK OF IRON DEFICIENCY?
- Women during their reproductive years and pregnancy
- Infants, children and teenagers
- Athletes and very active people
- Vegetarians and vegans
- People on restrictive or fad diets
Research shows thousands of New Zealanders, particularly those in the at-risk groups, are iron deficient.
HOW CAN I FIND OUT IF I'M IRON DEFICIENT?
The only way to find out for sure if you are iron deficient is to go to your doctor for blood tests. You should be aware there are several different tests for iron status. The first of these is haemoglobin, which effectively measures circulating amounts of iron. Haemoglobin does not reflect your long-term iron stores. For that, you need a serum ferritin test. It is possible to have normal haemoglobin levels, but low storage (ferritin) iron. Transport (transferrin) iron is another important indicator, which measures the amount of iron supplied to the bone marrow.
POSSIBLE CLINICAL EFFECTS OF IRON DEFICIENCY
- Fatigue and reduced tolerance to work
- Developmental delay and learning difficulties
- Reduced resistance to the cold
- Impaired immunity (increased frequency of infections)
- Reduced appetite
- Deterioration in athletic performance due to decreased aerobic capacity
- Premature births and low birth weights
- Long-term iron deficiency leads to anaemia with more severe symptoms
RECOMMENDED DIETARY INTAKE (RDI) FOR IRON PER DAY (mg)
- Infants 0-6 months = 0.2
- Infants 7-12 months = 11
- Children 1-13 years = 8-10
- Boys 14-18 years = 11
- Girls 14-18 years = 15
- Women 19-50 years = 18
- Pregnant Women = 27
- Breastfeeding Women = 9-10
- Women over 50 years = 8
- Men over 19 years = 8
WHAT ARE THE BEST SOURCES OF IRON?
Red meats are amongst the best sources of absorbable iron. Kidney and liver are particularly rich in iron. Lean beef and lamb are excellent sources of iron and have a higher iron content than pork, chicken or fish. In general, the redder the meat, the higher the iron content.
WHAT TO DO TO AVOID IRON DEFICIENCY AND HAVE A HEALTHY DIET
- Eat lean beef and lamb at least 3 to 4 times per week as an excellent source of iron. As a guide, a portion of meat should be about the size of the palm of your hand (not including fingers!) or a deck of cards.
- Eat meat, poultry or fish (haem iron foods) with vegetables, breads, pasta or grains (non-haem iron foods), as haem iron helps you absorb up to 4 times more iron from non-haem iron foods.
- Eat foods rich in vitamin C, eg oranges, kiwifruit and tomato, to help boost iron absorption from non-haem iron foods.
- Alternatively, drink diluted fruit juice with your meal, which is also high in vitamin C.
- Avoid drinking tea or coffee with main meals as they reduce iron absorption.
- Eat a variety of foods from the four food groups each day: - Breads and cereals -Fruits and vegetables - Meat and protein alternatives (eg eggs, tofu and beans) - Milk products .