Iron is a critical mineral necessary to sustain life. In humans, iron is most notably necessary as the critical component of hemoglobin that binds oxygen, and thus allows our red blood cells to carry oxygen to our tissues. Iron is involved in a host of other critical physiological functions, including energy production, neurotransmitter production, immune function, and many other biological processes. Most people are familiar with the concept of anemia caused by iron deficiency, or have perhaps experienced it themselves, as it’s a very common condition.
But what about too much iron? When iron is in excess we would call this “iron overload,” and although it is less well known, it can be just as problematic as iron deficiency. Let’s discuss what iron overload is, why it’s problematic, and what can be done if it is present.
Iron Overload: The Basics
We want appropriate amounts of iron for all the reasons already mentioned, especially so that we can appropriately carry oxygen to our tissues. But, just like with most things in life, there really can be too much of a good thing. When we have iron overload, or an excess of iron in the body, iron can build-up in organs and tissues where we don’t want it to be. And why is that problematic? Part of what makes iron so useful is its “oxidative” potential, allowing it to bind with oxygen in red blood cells. This is helpful for carrying oxygen, but when sitting in tissues this same oxidative potential can cause inflammatory damage. If you have seen rust before, you have seen oxidation in action: rust is the result of iron reacting with oxygen and moisture over time.
While you need not be concerned that small, orange pieces of rust are floating through your body, iron’s reactivity with oxygen means that when in excess, it can lead to oxidative stress, leading to inflammation in the body. For example, higher iron is correlated with higher oxidized LDL, a known risk factor for cardiovascular disease. It is also known that excess iron buildup in peripheral tissues leads to increased risk of diabetes and heart disease, and some research suggests this is due at least in part to mitochondrial dysfunction.
Who Might Have Iron Overload
The most well-known cause of iron overload is hereditary hemochromatosis (HH), a genetically-driven condition leading to excess iron buildup in the body. Those with HH are homozygous (have two copies) for variants of a gene, most commonly HFE, which is involved in iron regulation. Alterations in this gene, which regulates the production of a hormone hepcidin, leads to excess iron absorption. Those with HH may not have symptoms for some time, and may not know they have it until testing reveals high iron levels in the body. If present, symptoms could include fatigue, joint pain, abdominal pain, weight loss, palpitations and low libido, among others.
But iron overload is not only an issue in those with HH. There are several other factors that can lead to iron overload, including but not limited to: having one copy of a genetic variant (heterozygous), excess consumption of iron-fortified grains, and copper deficiency.
Additionally, men and postmenopausal women are at higher risk in general. This is because men and postmenopausal women don’t regularly bleed, which is one of the only ways we can actually remove iron from the body. Once iron is absorbed by the body, humans have no specific pathway for eliminating excess iron. Premenopausal women who are regularly having menstrual cycles are thus at lower risk, and are at much higher risk for actually being low in iron and having anemia.
The Bottom Line
If you are concerned about iron overload, you can have your healthcare provider check your levels, most importantly your ferritin (your iron storage protein) and iron saturation levels. If you have significant iron overload, you may need therapeutic phlebotomy in which you have a prescription to have your blood drawn regularly for a certain time period to help you lower iron stores (while avoiding going too low and causing anemia). For less severe iron overload, other options include blood donations (such as through the Red Cross) and/or a supplement known as lactoferrin, as well as a few other potential herbs and antioxidants.
It’s key to remember that, despite the dangers of excess iron, anemia is still more common than iron overload. Iron is a critical nutrient that many do not get enough of. In general, most people should not be concerned about consuming excess iron from the diet, especially since iron-rich foods like red meat are such valuable sources of a host of essential nutrients. The body typically is great at tightly regulating iron absorption. But under certain circumstances, overload may become an issue. Thankfully, if it is identified, we have ways to lower iron stores and reduce the oxidative, inflammatory load of excess iron.