Why we need iron
Photo by David Metzer on Unsplash
Red meat is often associated with being a good source of iron. However, are there other foods that also provide us with iron and why do we need it?
Why do we need iron?
Iron is a mineral that is essential for our health and wellbeing. We need iron to produce haemoglobin, the protein in red blood cells that carries oxygen from our lungs to where it is needed in our body. If the body’s cells do not get enough oxygen it can leave us feeling irritable and tired. Iron is also important for our immune system and brain development.
How much iron do you need?
We all need to get enough iron to ensure that we stay healthy. However, there are some specific groups of the population that have higher iron needs than other. Babies, children and teenagers all have higher iron requirements to support their rapid growth and development. In fact a 7 - 12 month old infant needs more iron than their dad! Pregnant and menstruating women also have higher requirements as do athletes, especially endurance runners.
Iron deficiency is the most common nutritional deficiencies in the world. It is the leading cause of anaemia, which affects 33% of non-pregnant women, 40% of pregnant women, and 42% of children worldwide. It can lead to fatigue, dizziness, headaches, poor immunity & impaired mental and physical performance, especially amongst children. Iron deficiency in children under two years, can have irreversible effects on brain development. Unfortunately research indicates that many Kiwi kids are not getting all the iron they need. In fact, more than half (66%) of Kiwi toddlers have been found to be at risk of inadequate iron intake, with 14 % of Kiwi kids under the age of two were iron deficient.
Nutrient Reference Values for Iron (Australia and New Zealand)
What foods are high in iron?
When it comes to the iron found in food, there are two different types - haem iron and non-heam iron.
Haem iron
Haem iron is easily absorbed by the body. It is found in:
Red meat (beef, lamb, pork, liver, kidney),
Poultry
Fish and
Seafood
Non-haem iron
Non-haem iron is not as easily absorbed by the body. It is found in plant foods such as:
Legumes (chickpeas, soy, tofu, baked beans, hummus),
Whole grains
Eggs
Dark leafy vegetables eg spinach, kale
Dried fruit eg dates, apricots
Nuts & seeds
Fortified-cereals eg weet biscuits.
Including foods rich in vitamin C at the same meal helps to increase the absorption of non-haem iron. Foods rich in vitamin C include citrus, kiwi, tomato, capsicum, parsely. Including haem (meat, poultry & fish) with non-haem foods also helps to increase absorption.
How much iron is in my food?
Outlined below is the amount of total iron you can find in some common foods:
½ c green mussels, marinated = 7.4mg
1 grilled lean beed steak (173g) = 5.8mg
100g tofu = 5.4mg
2 grilled lean lamb leg steaks (116g) = 4mg
1 cup boiled spinach = 2.5mg
½ cup baked beans or chickpeas = 1.6mg
10 dates = 1.3mg
1 grilled lean pork loin chops (74g) = 1.2mg
1 boiled egg = 0.9mg
However, as noted earlier, not all iron is created equal. Only about 5-12% of non-haem iron is absorbed by the body compared to 15-25% of haem iron. While it appears that 2c of cooked spinach contains about the same amount of iron as a grilled steak, the amount of absorbable iron will be far less from the spinach. In fact, Beef + Lamb New Zealand estimate that 19c of cooked silverbeet would provide the same amount of absorbable iron as a 120g lean beef steak.
What can inhibit iron absorption?
While foods rich in vitamin C and haem iron can increase the absorption of iron, some foods can actually inhibit it. Drinking too much milk, especially by littlies, can not only inhibit iron absorption but it can also take the place of iron-rich foods in the diet, leading to reduced iron intakes. Therefore, save milk for a snack, rather than drinking it alongside a main meal, which is rich in iron. Also limit milk, to no more than 500ml per day. Phytates can also inhibit iron absorption. Phytates are found in like whole grains, cereals, soy, nuts and legumes. Although phytates can inhibit iron absorption, the effects can be countered by including vitamin C-rich foods or haem sources of iron.
Did you know drinking tea can reduce iron absorption? If you are a tea drinker, don’t drink tea with your meals and then wait for about 1 hour after your meal before having a cup of tea again.
Can I still meet my iron recommendations if I’m vegetarian or vegan?
You sure can, although it may take a little more planning to ensure you’re getting all the iron you need. Pregnant women and athletes, who have higher iron needs, may find they need to use an iron supplement. Discussing your individual needs with a Registered Dietitian can help to ensure that you’re able to get all the iron you need.
Tips to help you get all the iron you need
Include a variety of haem and/or non-haem foods in your diet
Include plenty of vitamin C rich foods alongside your iron-rich meals and snacks
Drink tea and milk before or after meals, rather than alongside
If you feel your diet may be lacking in iron, contact your local Registered Dietitian for further advice.