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Can We Overload Ourselves With Iron?
14 Jul 2021
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A curious statement in the 'Iron' section of Optimum Nutrition Recommendations by Dr Greger (originally written in 2011, revised in 2016) caught my attention:

Iron: "All menstruating women should increase their absorption by combining foods rich in iron and vitamin C at meals and should get checked for iron-deficiency anemia every few years. Men should be checked for an iron overload disease before any attempt to increase intake."

How common is iron overload? This paper says,

"It is estimated that one in every 200 US Caucasians are positive for iron overload,"

"An estimated 16 million Americans have some degree of iron overload, either inherited or acquired."

Is iron overload harmful? The Dark Side of Iron - Why Too Much is Harmful (2017, HealthLine) is a good overview. For a long list of diseases associated with iron overload, just glance at this overview article by Iron Disorders Institute.

What did I learn so far? Iron overload is not as common as obesity, heart disease and diabetes. However, it's not rare either; it affects 16 million Americans! And it is associated with increased risks for myriad diseases.

How may we avoid iron overload? Dr Greger's videos below helped me understand a key concept: heme vs non-heme iron.

Heme vs Non-Heme Iron

Iron found in animal products (blood and muscle, for example) is called heme iron. Iron found in plants is called non-heme iron. Does our body process these two types of iron differently? Yes! Dr Greger's videos helped me understand the differences.

Overview articles: Iron and Heme Iron.

(2012) Risk Associated with Iron Supplements

(3 mins) Transcript. The title of the video suggests that the focus is supplements. However, it's a good video that summarizes the difference between heme and non-heme iron! Excerpts:

"Iron is a double-edged sword. If we don’t absorb enough, we risk anemia. But if we absorb too much, we may be increasing our risk of colorectal cancer, heart disease, infection, neurodegenerative disorders, and inflammatory conditions. Other conditions that have been associated with high iron intake include Alzheimer’s, Parkinson’s, arthritis, and diabetes." — Dr Greger

"Because the human body has no mechanism to rid itself of excess iron, we evolved to tightly regulate the absorption of iron. If our iron stores are low, our intestines boost the absorption of iron, and if our iron stores are topped off, our intestines block the absorption of iron to maintain us in that sweet spot. But this only works with the primary source of iron in the human diet—the iron found in plant foods. Our digestive system cannot regulate the iron in ingested blood—heme iron. The iron in animal foods can just zip right through our intestinal barrier—even if we already have too much in our system; we have no control over it." — Dr Greger

(2015) The Safety of Heme vs. Non-Heme Iron

(4 mins) Transcript. Excerpts:

"— if you just look at iron intake from meat, it's associated with significantly higher risk for heart disease. This is thought to be because iron can act as a pro-oxidant contributing to the development of atherosclerosis by oxidizing cholesterol with free radicals. The risk has been quantified as a 27% increase in coronary heart disease risk for every one milligram of heme iron consumed daily."

"Higher heme iron (animal iron) intake was significantly associated with greater risk for type 2 diabetes, but not total or non-heme iron (plant iron); 16% increase in risk for every daily milligram of heme iron consumed. And the same for cancer, with up to 12% increased risk for every milligram of daily heme iron exposure."

Iron Utensils

Can we boost our iron levels by cooking meals in iron utensils? Yes. Something to watch out for if we already have high iron levels.

(2020) Stainless Steel or Cast Iron: Which Cookware Is Best? Is Teflon Safe?

(6 mins) Transcript. An excerpt:

"A little leaching metal can be a good thing in the case of straight iron, like a cast iron skillet, which can have the beneficial effect of helping to improve iron status, helping to potentially reduce the incidence of iron deficiency anemia among reproductive-age women and children."

Lecture by Dr Peter Rogers
(11 mins, 2021) Iron Overload: Most Men Suffer From It

A fast-paced, information rich video.

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