A Summer of Football: Return to the Pitch Series - Blog 1 Iron

You’ve spent about a year locked up inside your houses unable to fully take part in the sport that you love – but now that it’s time to return to the pitch and the EUROs are on their way, let’s work on getting our nutrition on point.

As I’m sure many of us know, it’s very important to ensure you’re getting the right amount of carbohydrates, fats, and protein in the diet; and you’re timing your intakes appropriately around your day according to activity levels, training sessions, and matches. However, what many tend to forget to focus on as much is the micronutrient content of the diet. Today we’re going to focus on the micronutrient iron.

What do we need iron for?

Iron is a mineral that makes haemoglobin in our red blood cells, and its main function is to transport oxygen (that we have taken in from the air when breathing in) from the lungs to around the body. Also, it is a component of myoglobin that carries oxygen to muscle tissue. When we are exercising, this will play a role in aerobic energy production which essentially is the cells in our body creating energy for movement in the presence of oxygen. Therefore, iron will be an essential micronutrient for you to be including in your diet as a football player.

How much iron do you need?

An individual’s nutritional requirements of a macro-/micronutrient differ depending on their age, and for iron in particular this also depends on if you are male or female. The current reference nutrient intakes (RNIs) for iron are shown in the table below.

wiYou will notice that women need considerably more than men, especially in the 19-50 years period. This is due to the added pressures of losing blood during regular menstrual bleeding, and so the loss of iron in haemoglobin of red blood cells. This can explain why iron deficiency is more prevalent in female athletes (at about 15 – 35%), however, it is still seen in male athletes (about 5 – 11%). A rise in the reduction of meat in the diet could also be playing a part in iron deficiency as the type of iron found in meat (haem iron) is more easily absorbed than that in plant-based sources (non-haem iron).

What can happen if you don’t have enough?

Sustained low iron intakes could cause iron deficiency if the body’s stores of iron deplete, and eventually could cause iron deficiency anaemia which is a reduction in red blood cells and affects 4-9% of 1.5 – 64-year olds in the UK. It is also possible to lose iron through sweat when training heavily, and some is lost through urine and the gastrointestinal tract. Symptoms of iron deficiency and iron-deficiency anaemia include fatigue, increased rate of perceived exertion, restlessness, pale skin, poor recovery, and impaired performance.

Is too much a bad thing?

Yes. It is important to get your blood tested for iron levels by your GP before making assumptions and taking iron tablets without professional guidance. This is because iron toxicity can occur with excess supplementation. Make sure you see your GP before taking any iron supplements.

Types of iron:

1)      Haem iron

As was mentioned earlier, haem iron is the type of iron found in meat and is derived from the haemoglobin and myoglobin (oxygen transporters in animals) contained within it. It is in the ferrous form so it can be absorbed quickly, with around 15-35% of it being absorbed, and it contributes to 10% or more of our total absorbed iron.

Sources

·         Liver – for example, 100 grams of raw chicken liver contains 9.2mg of iron

·         Red meat – for example, 100 grams of raw extra lean minced beef contains 1.5mg of iron

·         Seafood – for example, 100 grams of raw oysters contains 5.7mg of iron

2)      Non-haem iron

Non-haem iron comes from plant-based sources and is less easily absorbed when compared to haem iron. Although non-haem iron is the main form of dietary iron, only 2-10% of the non-haem iron we consume is absorbed. This is because it is in the ferric state, which means before it is absorbed the body has to convert it to the ferrous form (which is found in haem iron), and so is a more complex process.

Sources

·         Beans – for example, 100 grams of raw red kidney beans contains 6.4mg of iron

·         Seeds – for example, 100 grams of pumpkin seeds contains 10mg of iron

·         Nuts – for example, 100 grams of almonds contains 3mg of iron

·         Legumes – for example, 100 grams of boiled red lentils contains 2.4mg of iron

·         Dried fruit – for example, 100 grams of dried apricots contains 4.1mg of iron

- Green leafy vegetables – for example, 100 grams of boiled broccoli contains 1.2mg of iron

Unlike haem iron, the absorption of non-haem iron can be affected by other components in the diet. The enhancers (increases absorption) and inhibitors (decreases absorption) of iron are included in the table below.

It’s important to think about ways you could increase the absorption of non-haem iron, especially if you don’t eat meat, by pairing them with enhancers and trying to limit their pairing with inhibitors. Unfortunately, a lot of plant-based non-haem iron sources also contain inhibitors or are regularly paired with inhibitors (such as fortified cereals with milk). Therefore, if you do eat a vegan or vegetarian diet, aim to pair with vitamin C where possible to promote iron absorption as you don’t want to be eliminating all foods that contain inhibitors - because ultimately these foods are also essential and provide many benefits.

Meal ideas

Scenario 1 – Chilli Con Carne

You have just finished a training session and are looking to replenish your glycogen stores and also help your muscles to recover. For a post-training meal, you would be looking for a meal high in carbohydrates and also protein, but if we would like to be including iron sources within this meal then Chilli Con Carne could be a great way to do this.

Carbohydrate

For the carbohydrate in this meal, include a medium to large portion (depending on the duration and intensity of your training session) of rice. If eaten within 1 hour of finishing your session it may be beneficial to have white rice due to the rate of absorption of glucose within the first hour being increased, which will help you replenish your glycogen stores more efficiently. However, it is after this period, or if you just prefer it, you could substitute for brown rice which contains more fibre and other micronutrients.

Protein (and iron)

Minced beef would provide a source of protein and haem iron (for a vegetarian or vegan, the minced beef could be swapped for a meat-free alternative or replaced with more beans), and red kidney beans a source of protein and non-haem iron.

Enhancers of iron absorption

To help absorb the non-haem iron you should include some enhancers. Minced beef in the meat option will enhance the absorption of non-haem iron, but you could also add some sources of vitamin C by using chopped tomatoes, peppers, and you could even include a 150ml glass of orange juice on the side or eat some kiwi fruit afterwards to help absorb more non-haem iron.

See the image below for the recipe for Chilli Con Carne (serves 1).

Scenario 2 – Fortified cereal-based meal

Cereal can be used both for breakfast and as a snack between meals if you like to eat cereals at any point in the day. For this example, you are eating breakfast 2-3 hours before a training session (to allow for proper digestion), so you are looking to fuel yourself with carbohydrates and also include some protein, but if we would like to be including iron sources within this meal then including fortified cereals in the diet is a good way to achieve this.

Carbohydrate

The main source of carbohydrates for this meal will be the cereal itself. For this example, we will be using a bran-type cereal, such as All Bran (it is important to bear in mind that this cereal is high in fibre, so allow extra time before training if you find this causes you gastrointestinal issues).

Protein (and iron)

Many kinds of cereal are fortified with non-haem iron, but It would be beneficial to add another source of non-haem iron to this meal because cereal is usually consumed with milk which acts as an inhibitor. In this example, we are going to add some dried fruit, such as apricots. The protein source for this meal will come from the milk unless you are using a plant-based alternative, and the cereal itself contains some protein (if you find you would like more protein in this meal then eggs or a protein shake could add some, however, try to use water with the shake to avoid adding more calcium).

Enhancers

As we just mentioned, this meal contains an inhibitor of iron so it will be even more crucial to include a source of vitamin C in this meal. This could be easily achieved by drinking a 150ml glass of orange juice with your meal or having more fruit containing vitamin C on the side.

See the table below for the ingredient list.

Other meal and snack ideas

·         Include sardines with toast, on crackers, on a salad

·         Greek yoghurt with dried fruit, pumpkin seeds, and citrus fruits

·         Steak with potatoes, broccoli, and Brussel sprouts

·         Lentil and bean pasta with a tomato-based sauce

·         Fruit, nut, and seed mix

Important points to take away from this blog

·         Try to include sources of iron regularly throughout your meals, this will be beneficial for your body to transport oxygen and create energy which will affect your performance capabilities

·         Combine haem and non-haem sources of iron (if dietary restrictions allow) to boost the iron contents of your meal

·         Women who have periods will need more iron than men

·         Including sources of vitamin C within a meal containing non-haem iron will help your body to absorb as much iron as it can

·         Be mindful that there are foods that contain iron absorption inhibitors, try to counteract this by including more enhancers

·         Avoid drinking tea or coffee around the time that you are going to eat a meal that contains iron

·         Speak to your GP before taking any iron supplements

We hope this blog on iron has been beneficial for you and helps you to see where you could be including iron in your fuelling or recovery meals for football. Make sure to tag us in any pictures of meals or snacks you create from this blog!

References

British Dietetic Association (2017) Iron [online]
Available on: https://www.bda.uk.com/resource/iron-rich-foods-iron-deficiency.html
[Accessed: 2nd March 2021]

Collins, J., Maughan, R.J., Gleeson, M., Bilsborough, J., Jeukendrup, A., Morton, J.P., Phillips, S.M., Armstrong, L., Burke, L.M., Close, G.L., Duffield, R., Larson-Meyer, E., Louis, J., Medina, D., Meyer, F., Rollo, I., Sundgot-Borgen, J., Wall, B.T., Boullosa, B., Dupont, G., Lizarraga, A., Res, P., Bizzini, M., Castagna, C., Cowie, C.M., D’Hooghe, M., Geyer, H., Meyer, T., Papadimitriou, N., Vouillamoz, M. and McCall, A. (2020) UEFA expert group statement on nutrition in elite football. Current evidence to inform practical recommendations and guide future research. British Journal of Sports Medicine [First Published online 23rd October, 2020] DOI: 10.1136/bjsports-2019-101961
[Accessed: 2nd March 2021]

Sim, M., Garvican-Lewis, L.A., Cox, G.R., Govus, A., McKay, A.K.A., Stellingwerff, T. and Peeling, P. (2019) Iron considerations for the athlete: a narrative review. European Journal of Applied Physiology, 119(7), 1463-1478.