Well the answer to the question is both, but that might be a surprise to you since iron has a clearly positive reputation among the general public. Iron is a mineral and a friend in that it plays a key role in the making of red blood cells. Too little iron may lead to anaemia, a low level of red blood cells. Anaemia can cause fatigue and other symptoms. Too little iron can also have disastrous effects on memory, growth, and overall physical health. It is often said that the more iron, the better. But that is actually not true since excess iron can be a foe. Let me explain in more detail.
Too much iron
Large amounts of ingested iron can cause excessive levels of iron in the blood. There is also the issue of haemochromatosis, a genetic disorder where affected people absorb too much iron from a perfectly normal diet. Excess iron is stored in the body. Over time this leads to iron overload.
The problem is that although we have mechanisms in place for regulating iron absorption, men of any age and post-menopausal women have no mechanisms that can get rid of excess iron, except by giving blood. That reminds me of medieval blood letting as a primitive “cure” for most diseases. There might actually be some benefits to such treatments.
Iron toxicity occurs when there is free iron in the cell, which happens when iron levels exceed the capacity of transferrin to bind the iron. Damage to the cells of the gastrointestinal tract can also prevent them from regulating iron absorption leading to further increases in blood levels.
High blood levels of free ferrous iron react with peroxides to produce free radicals, which are highly reactive and can damage DNA, proteins, lipids, and other cellular components. Observational studies have tracked such changes to the development of type 2 diabetes, heart disease, insulin resistance, inflammation, Alzheimer’s disease, hypertension, fatty liver, hypothyroidism, and arthritis. A daunting list of diseases connected to excess body stores of iron.
There is also the issue of the purported connection between red meat consumption and the development of colorectal cancer. One of the theories supporting this connection blame the high iron content of red meat.
Complicating things further, this is heaven for disease-causing bacteria. Like all living beings, bacteria need iron to survive and multiply. Excess iron promotes their growth and capacity to make you sick.
So what to do?
Let’s first look at iron intake. You can certainly get enough iron from food. Iron absorption is best (15-18%) from foods that contain haem iron. Red meat, seafood and poultry are the best sources of haem iron. Iron absorption from foods that contain non-haem iron is much lower (<5%). Non-haem iron is predominantly found in plant foods such as cereals, vegetables, legumes and nuts.
In case of a deficient diet it is also possible to use iron supplements to improve iron status. Iron supplements are often used to treat anaemia caused by pregnancy, heavy menstrual periods, kidney disease and chemotherapy. Iron supplements are commonly recommended for infants and toddlers, teenage girls, and women who are pregnant or of childbearing age to help prevent anaemia.
But if you actually need less iron?
Phytonutrients like polyphenols, flavanols and other plant-derived antioxidant compounds inhibit iron absorption. They can be found in apples, onions, grapes, many other plant foods, and in most colourful spices and herbs.
Even low levels of phytates have a strong inhibitory effect on iron absorption. Phytates can be found in walnuts, almonds, sesame, dried beans, lentils, peas, cereals and wholegrain.
A cup of coffee after dinner is particularly good at inhibiting iron absorption with instant coffee the most effective. Tea might even be better. Tannins in coffee and tea bind the iron and prohibit absorption.
But there is more help at hand in a piece of cheese after dinner. The calcium it contains is a potent inhibitor of iron absorption. More than that, calcium reduces any carcinogenic interactions between haem iron and colonic cells.
If you’re going to drink alcohol, make it red wine and lean toward lower-alcohol wines. Its polyphenols inhibit iron absorption, while straight ethanol enhances iron absorption.
And if that is not enough you might try some ancient blood letting or in simple terms become a blood donor.