Decreasing iron with diet

‘Wait, why would I want to decrease my iron absorption? I thought it was a good thing.’  In the right doses iron is great for the body, its needed for so many functions.  However, like I’ve alluded to in this article, excess iron can also be quite a problem.  The advice in this article is tailored to those with iron excess, though reversing the advice can be useful if you’re trying to increase iron levels.

This article will be discussing the 2 different types of iron and where to find them, and more importantly, the specific food combinations that can increase or decrease your iron absorption from a meal.

Breaking down iron

You’re probably aware that there are 2 types of iron available from food, Heme and non-heme.

The only source of heme iron is from meat, including seafood and shellfish.  All other sources of iron, such as leafy vegetables, nuts and fortified cereals include non-heme iron.  Interestingly, meat contains more non-heme (55-60%) than heme (40-45%) iron.

Why is this important?

For those with normal iron metabolism, heme iron is absorbed much easier (25-30%) than non-heme (5-15%) [1] and absorption is higher for those with haemochromatosis [2].  Except for calcium, the nutrients and foods listed below all work on altering non-heme iron absorption.

Perhaps the most straightforward way of reducing iron intake from the diet is to know what foods are rich in iron and avoid or reduce consumption of those.  However, many iron containing foods have plenty of other micronutrients that you may still want or you may not be willing to give up those foods.  This is where iron inhibiting foods and herbs come in.

Food combinations

What decreases iron?

·      Polyphenols and tannins

o   Foods containing polyphenols and tannins have been shown to inhibit iron uptake, some in a dose-dependent manner [3] [4]

o   Examples include

§  Coffee [5]

§  Green tea [6] [7]

§  Rosemary [8]

§  Turmeric [9]

§  Many more

·      Eggs

o   The protein phosvitin, found in eggs, can lower iron absorption from meals, in a dose-dependent manner [10]

·      Phytic acid

o   Phytic acid, a compound found in grains, nuts and legume can also decrease the absorption of iron [11]

o   Soaking, fermenting and sprouting these foods reduces the phytates available

o   Phytic acid also blocks the absorption of other minerals such as calcium and zinc [12] so use with caution.  Even with iron overload I still seek to reduce phytic acid from foods as I digest them much better

·      Calcium

o   Calcium, both supplemental and from foods, lowers heme and non-heme iron absorption [13] [14]

o   This includes calcium from dairy and vegetables

·      Peppermint

o   The common garden herb peppermint can also lower iron absorption [15], so sipping a tea before a meal is a great way to reduce iron absorption, whilst also improving digestion

 

 

What increases iron?

The following nutrients and techniques can increase the absorption of iron from a meal

·      Vitamin C [16]

o   Foods such as tomato and lemons

·      Carotenoids [17]

o   Foods such as (you guessed it) carrots and sweet potatoes

·      Cast Iron pans

o   Cooking in cast iron pans can leach iron into the foods, particularly when acids are used

·      Heme iron

o   Increases the absorption of non-heme iron [18]

·      Alcohol consumption [19]

o   For those still wanting to consume alcohol, red wine contains both polyphenols and tannins, which can mitigate some of the effects of the alcohol

o   Having the alcohol away from the high iron meal is another option

  

Action plan

The action plan is simple, when trying to decrease your iron load include more of the iron-inhibiting foods in your diet and less of the foods that increase absorption (simple hey?).  This does not mean you can never squeeze some lemon on your food or eat sweet potato with your greens ever again, but it helps to be mindful of doing this too often.

What’s one dietary change you’ll make?