Iron is one of the key minerals for runners. However, runners tend to suffer from iron deficiency and anemia.
Iron is vital for producing hemoglobin, the protein contained in red cells which carries the oxygen we breathe to the tissue and the carbon dioxide from the tissue to the lungs that expel it.
Moreover, iron is important for the synthesis of myoglobin, the protein in charge of the storage and use of oxygen in the muscles.
As a result, iron is essential for runners’ performance and it is vital to know how to keep iron levels high by means of the daily diet.
“HEME IRON” & “NON HEME IRON”
“Heme iron” is the type of iron that is more easily absorbed. It can be found in seafood, meat, poultry and fish.
On average, people absorb between 15 percent and 35 perccent of the iron they consume.
“Non heme iron” is found in vegetables as well as in eggs and milk. It is not as easily absorbed as “heme iron”.
Moreover, sources of non heme iron tend to contain phytates, substances that mix with iron and carry it through the digestive system without allowing it to be absorbed.
As a result, some foods that contain high amounts of iron are not necessarily the best sources of iron.
For example, spinach contains a high amount of iron, but less than 2 percent of the iron contained in cooked spinach is absorbed (Scrimshaw).
TRICKS TO ATTAIN A BETTER ABSORPTION
Even though the absorption of non heme iron is low, this does not mean that those foods are not useful to increase iron reserves.
We will now give you some pieces of advice for you to manage to increase iron absorption.
– GOOD COMBINATIONS
We recommend you that, together with sources of non heme iron, you add the following ones:
– Vitamin c
The intake of foods rich in vitamin c, together with sources of non heme iron, may help you increase your iron absorption.
A good way would be to have an orange or kiwi smoothie during your meals.
– Heme and non heme iron
Combining sources of heme and non heme iron helps increase the absorption of the latter.
This means that combining meat and eggs or salmon and spinach are good alternatives to increase your iron reserves.
– WHAT YOU SHOULD AVOID
Apart from those combinations that may help you, there are others that can reduce iron absorption and that should be avoided:
Avoid having tea together with iron-rich foods since it reduces the absorption of this vital mineral. Take the most of tea and have it between meals (not during them).
Coffee is another infusion that can reduce iron absorption and which should be avoided during meals (and immediately after them).
– Calcium-rich foods
Calcium-rich foods are also calcium absorption depressants and, for that reason, they should be avoided in some meals.
Considering that calcium is another vital mineral for runners’ health and performance, an alternative should be to increase calcium or iron reserves since their combination will tend not to work.
The problem with iron (and other minerals) is that some foods tend to contain absorption depressants (like those calcium-rich foods), but that does not mean that you should choose between one or the other.
If your health and performance are in good conditions and your diet is full of nutritive and healthy foods, you should not worry too much about the combinations.
However, if you have symptoms of low levels of iron, you should visit your physician, strengthen your feeding and have iron supplements, in case the physician recommends this.
– Iron deficiency http://sopajaramillo.org/2012/IronDeficiency.pdf
– Erythorbic acid is a potent enhancer of nonheme-iron absorption. http://www.ncbi.nlm.nih.gov/pubmed/14684404
– Effect of tea and other dietary factors on iron absorption. http://www.ncbi.nlm.nih.gov/pubmed/11029010
– Estimation of Dietary Iron Bioavailability from Food Iron Intake and Iron Status http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4214798/
– Calcium and iron absorption: mechanism of action and nutritional importance. http://europepmc.org/abstract/MED/1600930
flickr photo by JD Hancock http://flickr.com/photos/jdhancock/7179891505 shared under a Creative Commons (BY) license