dnaMD Nutrition- The Celtic Curse & the HFE gene
In this article, we are spotlighting a particular genetic condition that impacts those of Irish descent more than any other population- hemochromatosis. Hereditary hemochromatosis is a genetic condition that causes people to absorb too much iron from their diet. While the normal iron absorption rate is 8-10%, those with hemochromatosis absorb over 40% of the iron in their food.
Hemochromatosis is a fascinating example of how the diet of our ancestors directly impacts our health today!
What is hemochromatosis?
Hemochromatosis is caused by the presence of a gene in your DNA- the HFE gene. This gene is responsible for the creation of a protein that is involved in iron absorption and causes the body to consume excess iron in food and water if necessary. When working properly, this gene also helps control and regulate your iron absorption rate. A feedback loop then communicates to the body when too much iron has been taken in and the absorption process pauses until needed again.
For someone who has hemochromatosis, the HFE variation does not tell the body when it has taken in too much iron. Rather, it perpetually signals to the digestive system to continue to absorb more and more iron. Eventually, having this variation in the HFE gene will cause an iron overload. The excess iron will be deposited in vital organs like the heart, liver, brain and pancreas. The iron overload will negatively impact the organ’s function, leading to liver failure, dementia, and heart failure.
The most common and severe form of hemochromatosis is when someone has two copies (homozygous) of a variation of the HFE gene. However, even having one copy of the HFE variant linked with hemochromatosis can cause health problems for an individual.
Luck of the Irish?
The HFE mutation that is linked to hemochromatosis arose in Europe around 6,000 years ago, alongside the emergence of agricultural settlements from the former hunter-gatherers. The mutation is more so prevalent in regions of Europe that are cold and rainy. This is likely due to nutrient deficiencies that would have caused an increase in iron absorption to be very beneficial.
In other regions where a bountiful array of iron was available, the gene was virtually eliminated through natural selection. But, in Northern Europe, it stayed preferable for survival - largely due to iron being an essential component of maintaining body heat, crucial in cold, wet climates.
In Ireland, nearly 1 in 5 people are carriers of the HFE gene linked to hemochromatosis with 1 in 83 people having two copies of the gene. In Europe as a whole, only 1 in 350 people have 1 copy of the gene. This gene became common in Ireland due to their overwhelming reliance on potatoes as their primary source of nutrition in the 17th and 18th centuries.
From 1845 to 1852 Ireland suffered The Great Hunger known as the Irish Potato Famine when a virulent fungus wiped out the potato crop. Those with the hemochromatosis gene were able to absorb more iron from a reduced amount of food. Those without the HFE variant were at a severe disadvantage in the face of limited dietary iron. As iron is absolutely essential for the human body, non-carriers of the gene would have died in disproportionately large numbers. Also women without the HFE gene would not have been able to carry a child due to low levels of iron. For these reasons, the HFE is much more common in those of Irish descent as having the gene allowed survival and persistence of the gene.
Today, with an abundance of iron fortification in our foods, the HFE gene is not only not needed but can be a disadvantage. While more common in the Irish, those of northern European descent should also be tested.
Symptoms of Hemochromatosis
It is important to know if you have a variant of the HFE gene linked to hemochromatosis. While iron-overload does take several years to build up enough to cause symptoms, they are very serious. Too much iron in the body can cause many severe symptoms, including:
Joint pain and osteoporosis
Neurodegenerative disorders (Multiple Sclerosis, Alzheimer’s disease, Parkinson’s’, epilepsy, and Huntington’s disease)
Cirrhosis of the liver
Men typically begin to see symptoms earlier than women. While women see symptoms 10-15 years after menopause, men begin symptoms in their 20’s and 30’s. Men also have a 24-fold increased rate of hemochromatosis compared to women.
Adjusting your lifestyle to the HFE gene:
Through genomic testing, you will be able to know if you have an HFE variant and will be able to adjust your lifestyle accordingly. Those with too much iron in their body should take the following steps:
Reduce the amount of iron absorbed by the body by avoiding iron-rich foods and alcohol. Liver, mussels, cooked bee, chicken, turkey, cooked beans, apricots, peas, nuts, spinach, and broccoli are all foods high in iron.
Remove excess iron from the body by removing blood from the body. For severe cases, this may entail removing a unit of blood a week until iron levels for normal. After that, giving blood every several months will be sufficient.
There is no cure for hemochromatosis, as it is a genetic condition. Treatment is simply to limit your iron intake and reduce the stored iron in your body tissues. If you get a diagnosis early before any organ damage, you will live a normal life expectancy.