Why Iron Is the Most Underrated Factor in Health

P. D. Mangan
Apr 19, 2016 · 5 min read

You’ve got your diet and exercise locked down, you sleep well, take a few supplements, and in general, you follow good health practices. Is there anything you’ve forgotten?

Yes — excess iron, the most overlooked factor in health. Iron, which accumulates in our bodies over a lifetime, can cause heart disease, cancer, diabetes, Alzheimer’s and Parkinson’s diseases; it can increase the rate and severity of infections and lead to faster aging.

Evolution and iron

Iron is a required nutrient: we need it to make red blood cells to carry oxygen, for energy production, and for many other critical functions. In the course of our long evolutionary history, iron has not always been abundant in our food; for this reason, as well as its critical necessity, our bodies have evolved mechanisms to grab iron and hold on to it. But we have not evolved any way of getting rid of it.

When humans are growing, they require plenty of iron for their development, but after maturity, the iron accumulates, often to high enough levels to damage cells and lead to disease.

Iron is a reactive element. When exposed to air and water, it rusts, and when inside our bodies, it can react with components of our cells — lipids, proteins, cell walls — and damage them. That’s how it leads to illness and premature aging.

Men, women, and iron

Women live longer than men — about four years longer, in the present-day United States. Men suffer higher rates of heart disease, cancer, Alzheimer’s, Parkinson’s, and diabetes.

Women also have much lower levels of iron in their bodies than men. Two factors are responsible for this: 1) blood stores most of the iron in the body, accounting for up to 80% of all iron; 2) pre-menopausal women lose blood through the menstrual cycle. As a result, until menopause, women accumulate much less iron than do men.

At age 45, men have about four times the amount of iron in their bodies than women, and at the same age, men have about four times as many heart attacks as women.

For a long time, doctors and scientists ascribed the startling sex difference in heart disease risk to hormonal differences. But in 1981, Dr. Jerome Sullivan first proposed that the difference was due to the far higher iron levels in men.

After menopause, iron levels in women begin to rise, and so do their rates of heart disease, but on average, their levels never catch up to men.

Blood donors are healthier than non-donors

Blood donors lose large amounts of iron with each donation, and they also have lower rates of heart disease, as much as 88% lower.

The immediate objection to this fact is that blood donors are likely to be healthier than non-donors even before they give blood, since they can’t be accepted for the donation if they are unhealthy, nor would they be likely to donate if they felt unwell.

To get around this, a number of studies have looked at health differentials between frequent donors and non-frequent donors. Frequent donors have better health and lower heart disease rates than non-frequent donors.

Lowering iron through therapeutic phlebotomy (bloodletting) results in much lower cancer rates: 35% less, and a 60% lower risk of death from cancer.

Coffee, tea, chocolate, and the Mediterranean diet

Many studies have reported on the beneficial effects on health of coffee, tea, and chocolate. Frequent coffee drinkers have lower death rates, and high consumption of chocolate has the same effect, for example.

It turns out that these all inhibit the absorption of iron from food.

The Mediterranean diet, which emphasizes a high intake of fruits, vegetables, fish, olive oil, and red wine, as well as low consumption of red meat, results in lower rates of heart disease and cancer than a typical Western diet.

The Mediterranean diet results in far lower levels of body iron, about half as much as in those eating a typical Western diet. The fruits and vegetables, olive oil, and red wine in the Mediterranean diet all inhibit iron absorption, and red meat, which is high in iron, isn’t consumed as much.

The lower body iron that comes from consuming a Mediterranean diet may be responsible for most or all of its beneficial effects on health.

Why Don’t We Hear More About Iron and Health?

The skeptical reader may wonder: if iron is as important to health and disease as I claim in this article, why we don’t hear more about it?

Physicians and scientists are familiar with the dangers of very high iron, seen in such disorders as hemochromatosis, or hereditary iron overload. But the levels of iron discussed in this article as capable of causing diseases are within a range that doctors consider normal.

In the case of heart disease, the cholesterol theory has held sway for most of the past several decades. Doctors and scientists enamored of this theory may be reluctant to consider the prospect that iron may play a large role. As Max Planck said, science advances one funeral at a time.

In the case of diseases like cancer or Alzheimer’s, the role of iron is a fairly recent discovery and is only now coming to be considered seriously.

Perhaps the most compelling reason why iron has been such a neglected topic in health and disease is because there’s little money to be made from it. Pharmaceutical companies can’t make huge profits from lowering iron and therefore have no incentive to promote the idea. In turn, physicians don’t hear about it.

The interventions that lower iron, which include blood donation, or natural compounds like curcumin and green tea extract, are all cheap or even free.


Iron is an important cause of aging and disease. Keeping iron levels from becoming excessive could prove to be one of the most important things you can do for health and long life.

This article has only touched on some of the most important aspects of iron as it relates to health, and most scientific references have been omitted for the sake of simplicity.

Better Humans

P. D. Mangan

Written by

Health, fitness, and anti-aging through lifting weights, paleo diet, and intermittent fasting. I’ve written 6 books on health and fitness.

Better Humans

Better Humans is a collection of the world's most trustworthy writing on human potential and self improvement by coaches, academics, and aggressive self-experimenters. Articles are based on deep personal experience, science, and research. No fluff, book reports, or listicles.

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