Your body tightly regulates the amount of iron that it absorbs. Too much iron can cause a lot of damage! Genetic mutations can cause you to absorb a little too much iron through your lifetime, resulting in a disease called hemochromatosis.
Knowledge is power here. Knowing that you carry the genetic variants for hemochromatosis can literally add years to your life since you can prevent the buildup of iron through giving blood.
23andMe and AncestryDNA genetic data can tell you if you likely carry the more common genetic mutations for hemochromatosis. Read on to find out how to check your data…
What is hemochromatosis?
Hemochromatosis is the disease state of building up too much iron in the body. It can be caused by genetic mutations in iron-related genes, or it can be due to excessive blood transfusions for anemia or liver disease. [Mayo clinic article]
Iron is essential – but needs to be in just the right amount. People with hereditary hemochromatosis absorb more iron from food than they should due to genetic variants.
Once iron is absorbed in the intestines, the body doesn’t have a good way to get rid of it. Normally, the body tightly regulates the amount of iron absorbed. When a little bit too much iron is absorbed, such as for people carrying genetic variants that cause hemochromatosis, the excess builds up over time. The body stores the excess iron in the organs, including the liver, heart, pancreas, skin, pituitary, and thyroid. You also can store iron in your joints and bone marrow. [ref]
Symptoms of building up too much iron can include:
- joint pain
- abdominal pain
- liver disease
- irregular heartbeat
- bronzed skin color
- elevated blood sugar and more.
Why do we need iron?
Iron is used by the body in numerous ways. In fact, every cell in the body uses iron in one form or another. Iron is involved in redox reactions, moving electrons in the mitochondria to produce energy. It is also needed in red blood cells as a critical component for moving oxygen throughout the body.
When you think about iron out in nature, rusty old iron parts may come to mind. Rust forms because iron can be easily oxidized, forming compounds with oxygen. This ability to move electrons around makes iron incredibly important – and also incredibly reactive – in the body.
Regulating Iron in the Body:
The body regulates the absorption of iron tightly. Not only do we need to control oxidation (no ‘rusting’ in the body ;-), but our body also regulates iron to keep it away from iron-loving bacteria. Certain pathogenic species of bacteria thrive and multiply rapidly when the iron is available. Thus, we don’t want too much iron in the body, and we have ways of quickly sequestering, or storing, the iron when the body is fighting off a pathogen.[ref]
Hepcidin is the iron regulatory hormone produced by the liver. Hepcidin was discovered and named in 2000, and scientists have since figured out that it controls the regulation of iron in the body and responds to lipopolysaccharides, a component of bacteria, to prevent iron-loving bacteria from reproducing rapidly.[ref]
The HFE gene was discovered in 1996 and linked to hereditary hemochromatosis. This gene codes for a protein that controls how iron is taken into the intestinal cells. Free iron is bound to transferrin, which then binds to a transferrin receptor in order to be taken into the cell. HFE can also bind to the transferrin receptor, blocking the receptor from taking iron into the cells. In this way, HFE is a negative regulator of iron absorption. [ref]
When there is too much absorbed, whether because of a mutation in the HFE gene or other genes regulating iron, the body stores it in different organs. Excess iron causes oxidative stress and DNA damage to the tissue. This can cause fibrosis and cell death, leading to cirrhosis of the liver or other organ damage.[ref]
Hereditary Hemochromatosis – HFE mutations:
There are multiple causes of hereditary hemochromatosis. The most common cause is a genetic variant that impacts the HFE gene. This allows too much iron to be absorbed into the body and is called type 1, or classic, hemochromatosis.
Other rare causes of hemochromatosis include mutations in other genes involved in hepcidin regulation and in the transport of iron. These are known as hemochromatosis type 2, 3, and 4.
Interestingly, hemochromatosis was first described in the 1700s as ‘bronze diabetes’ or ‘pigmented cirrhosis. This refers to the way iron accumulating in the skin can make it look bronzed, along with the damage to the pancreas causing diabetes or the liver causing cirrhosis. [ref]
How rare is hemochromatosis?
The variants in the HFE gene are more common in people of Northern European heritage. But not everyone who carries the variants will end up with a diagnosis of hemochromatosis. Estimates show that 1in 8 to 1 in 16 Caucasian people carry one copy of an HFE variant (more on this below).
Studies on hemochromatosis vary quite a bit in their estimates of how common hemochromatosis is amongst people with the variants, and this is mainly due to differences in the clinical definition. Some define hemochromatosis as having a ferritin (measure of storage iron) level of over1,000 mcg/l — along with liver disease, heart failure, and bronzed skin. Others define hemochromatosis as having elevated ferritin (>300 mcg/l) along with liver failure. [ref]
The question, then, is whereupon the spectrum of organ damage do physicians define hemochromatosis – is just having the pancreas damaged and causing diabetes enough, or do you also need liver damage? The clinical diagnosis and research study definitions vary quite a bit.
Problems with iron long before hemochromatosis diagnosis:
As you can imagine, the symptoms of iron building up can occur over the decades leading up to the point of organ failure. Joint pain, fatigue, and irritability are common complaints in people with HFE genetic variants. Common diagnoses prior to learning about hemochromatosis include fibromyalgia and arthritis. [ref][ref] Reduced libido and erectile dysfunction in men is common with iron build up. Diabetes and heart disease diagnosis also can often precede the clinical diagnosis of hemochromatosis.[ref]
The key here is that all of these problems due to excess iron can be prevented. You aren’t destined to have aches and pains leading up to liver failure or diabetes — knowledge is power here and iron levels can be reduced. (More on this in the Lifehacks section below).
Check your genetic raw data for hemochromatosis mutations:
Check your genetic data for rs1800562 C282Y (23andMe v4, v5; AncestryDNA):
- A/A: two copies of C282Y variant, most common cause of hereditary hemochromatosis, highest ferritin levels
- A/G: one copy of C282Y, increased ferritin levels, hemochromatosis possible but less likely, check to see if combined with H63D (below) – combo increases risk of hemochromatosis
- G/G: typical
Members: Your genotype for rs1800562 is —.
Check your genetic data for rs1799945 H63D (23andMe v4, v5; AncestryDNA):
- G/G: two copies of H63D variant, can cause (usually mild) hemochromatosis, increased ferritin levels
- C/G: one copy of H63D, somewhat higher ferritin levels, can cause hemochromatosis in conjunction with one copy of C282Y (above)
- C/C: typical
Members: Your genotype for rs1799945 is —.
Check your genetic data for rs1800730 S65C (23andMe v4; AncestryDNA):
- T/T: two copies of S65C variant, can cause (milder) hemochromatosis, increased ferritin levels
- A/T: possibly increased ferritin levels
- A/A: normal
Members: Your genotype for rs1800730 is —.
Carrying just one copy of the HFE mutation:
While most of the official hemochromatosis sites will say that you are ‘just a carrier’ for hemochromatosis with one copy of the HFE variant, in actuality, excess iron could be causing problems (just not usually to the extent of liver failure). The initial problems that come with too much iron include random joint pain, fatigue, irritability, and/or abdominal pain.
Research studies also show that carriers of HFE variants (mainly C282Y) are at a higher risk of :
- non-alcoholic fatty liver disease [ref][ref]
- metabolic syndrome [ref]
- cardiovascular disease [ref] including women with heterozygous variants [ref]
- slightly higher risk of cancer [ref] [ref] including breast cancer[ref] and liver cancer [ref]
- Alzheimer’s disease, including heterozygous carriers [ref]
- musculoskeletal problems (arthritis symptoms) [ref]
- high blood pressure [ref]
- high uric acid (gout) [ref]
- lung fibrosis [ref]
- cardiovascular disease in kidney disease patients [ref]
- increased lead levels [ref] [ref]
Other Genes Involved in Iron Buildup:
Not everyone who is homozygous or compound heterozygous for the hemochromatosis variants will develop iron overload. Diet and lifestyle play a role in the rate at which iron accumulates. Additionally, there are other genes that play a role in ferritin levels and iron levels in the body. Some of these are listed below:
BMP2 gene: bone morphogenetic protein influences hepcidin levels, which regulates iron accumulation
Check your genetic data for rs235756 (23andMe v4; AncestryDNA):
- G/G: lower transferrin
- A/G: increased transferrin
- A/A: most common genotype; increase ferritin levels in people with HFE variants [ref] [ref]
Members: Your genotype for rs235756 is —.
Check your genetic data for rs3923809 (23andMe v4, v5; AncestryDNA):
- G/G: higher ferritin levels [ref]
- A/G: higher ferritin levels
- A/A: lower ferritin levels
Members: Your genotype for rs3923809 is —.
TMPRSS6 gene: Transmembrane Protease gene, Serine 6 which regulates hepcidin levels
Check your genetic data for rs855791 (23andMe v4, v5; AncestryDNA):
- G/G: higher iron stores in men with HFE variants[ref]
- A/G: higher iron stores in men with HFE variants
- A/A: lower iron stores in men
Members: Your genotype for rs855791 is —.
Rare genetic mutations causing other forms of hemochromatosis:
Hemochromatosis can also be caused by mutations in other iron regulatory genes. These are really rare, but the mutations can cause hemochromatosis starting at a young age.
Check your genetic data for rs121434375 (23andMe i5001498 v4; AncestryDNA):
- A/A: typical*
- A/T: HFE2 mutation, pathogenic for hemochromatosis type 2A [ref]
*Note: given in forward orientation to match 23andMe or AncestryDNA data
Check your genetic data for rs28939076 (23andMe v4; AncestryDNA):
- G/G: typical
- G/T: Hemochromatosis type 4 mutation[ref]
Check your genetic data for rs74315325 (23andMe i5001502 v4; AncestryDNA):
- T/T: typical*
- T/A: Hemochromatosis type 2A [ref]
Check your genetic data for rs74315326 (23andMe i5001503 v4; AncestryDNA):
- T/T: typical
- C/T: hemochromatosis type 2A[ref]
- Hemochromatosis type 2A: listed in 23andMe as i5001503 (T is the risk allele)(v.4) [ref]
- Hemochromatosis type 4: i5006507 (T is the risk allele)(v.4)[ref]
- Hemochromatosis type 4: i5006505 (A is the risk allele)(v.4)[ref]
- Hemochromatosis type 2B: listed in 23andMe as i5003867 (T is the risk allele)(v.4) [ref]
- Hemochromatosis type 1: i5012781 (C is the risk allele)(v.4) [ref]
- Hemochromatosis type 1: i5012784 (C is the risk allele)(v.4) [ref]
- Hemochromatosis type 1: rs1800562 (A is the risk allele) (v.4 and v.5) [ref]
Knowledge is power. Knowing that you carry the mutations that cause hemochromatosis can save you from years of chronic diseases (diabetes, liver disease, heart disease, etc).
Get a blood test done!
Go get your serum iron, TIBC, and ferritin levels checked — or ask your doctor to test them. Ordering serum iron w/ TBIC and ferritin should give you enough information to know if you are storing too much iron. An inexpensive option if you want to order your own test is UltaLabs.
Give Blood Regularly
The simplest way to manage iron levels is to go give blood! You will feel good, and you will definitely help out someone else with your blood donation. It is a win-win!
Natural Iron Chelators and Inhibitors:
In addition to giving blood, natural and pharmaceutical iron chelators have been used to reduce iron levels in the body.[ref]
Quercetin, a flavonoid found in fruits and vegetables, has been studied for its iron-chelating properties.[ref] A 2017 study on dendritic (immune system) cells found that quercetin “increases extracellular iron export, resulting in an overall decrease in the intracellular iron content and consequent diminished inflammatory abilities.” And a 2014 study on quercetin concluded: “Potentially, diets rich in polyphenols might be beneficial for patients groups at risk of iron loading by limiting the rate of intestinal iron absorption.” Foods high in quercetin include apples, dark cherries, tomatoes, capers, onions, and cranberries. Quercetin supplements including pure quercetin powder are also readily available.
Another flavonoid, rutin, which is a metabolite of quercetin, has also been studied for its iron chelation properties.[ref] A 2014 study in rats found: “Rutin administration to iron-overloaded rats resulted in a significant decrease in serum total iron, TIBC, Tf, TS%, ferritin levels…” Foods high in rutin include capers, black olives, buckwheat, asparagus, and berries. Rutin is also available as a supplement.
Okra: A 2015 study found that okra “dramatically decreases intracellular iron levels in H63D cells compared to untreated cells”.[ref] Time to make some gumbo or fried okra!
Dietary phenols such as EGCG from green tea and grape seed extract also have been shown to inhibit iron uptake in the intestinal cells. [ref]
The jury is still out on curcumin. In a double-blind, placebo-controlled, randomized, cross-over study, curcumin was found to decrease hepcidin and increase ferritin.[ref] Other studies, though, refer to curcumin as a possible iron chelator.[ref]
Taurine, in a mouse model of hemochromatosis, was found to protect against liver damage from excess iron. The study is worth reading and looking into if you are worried about iron-induced liver damage.
Iron Fortified Foods…
Iron-fortified foods may be a problem for those carrying the hemochromatosis genetic variants. In the US, white rice and refined wheat products are fortified with iron.
- A Swedish study looked at the effect of iron-fortified foods on iron absorption in men with hemochromatosis. The study found that eliminating iron fortification from foods significantly reduced the iron absorbed by the men in the study. The study also found that the time needed between phlebotomy (to maintain proper iron levels in hemochromatosis patients) was increased significantly.
- A US study in 2012, though, declared that there is no evidence that dietary iron content made a difference in ferritin concentration. In the study, they gave 200 people (homozygous for the HFE C282Y variant and high serum ferritin levels) surveys asking for information on the type of diet they had eaten for the last few years as well as alcohol intake. Then they compared the survey data to their serum ferritin levels to look for a correlation and drew the conclusion that iron intake doesn’t impact hemochromatosis. [ref]
Leaches and Bloodletting…
It hit me while researching all of this, that the bloodletters of yesteryear probably did some good for the minority of people who were overloaded with iron. Leeches to reduce blood and iron stores were probably effective against bacterial infections from iron-loving bacteria.
Fortification of iron into all wheat products in the US, which began in the 1940s, is good for children and most women of childbearing age, but it adds to the iron overload burden for some men and older women. When looking at the forced fortification of foods with iron and folic acid, it really does seem that the policymakers are focused on the majority, at the expense of a minority who genetically are harmed by it. Since iron can takes decades to build up in the body, it may be that we are now seeing the consequences in the baby boomer generation.
Additional research studies:
- The impact of H63D HFE-gene carriage on hemoglobin and iron status in children.
- Mitochondrial DNA Damage in Iron Overload
- Eighty percent of French sports winners in Olympic, World and Europeans competitions have mutations in the hemochromatosis HFE gene.