Dr. Day is a cardiologist and Medical Director of Heart Rhythm Services at his practice in Salt Lake City, Utah. He graduated from Johns Hopkins Medical School and completed his residency and fellowship in cardiology at Stanford University. He is board certified in Cardiology and Cardiac Electrophysiology.
Does Iron Increase Your Risk of a Heart Attack?
Marci was anemic and tired all of the time. Her doctor prescribed high doses of iron and recommended eating more iron-rich red meat to help her body make more blood so that she would no longer suffer from iron-deficiency anemia.
Marci, though, was worried about this treatment plan given her family history of heart disease. What should she do?
In this article we will explore the “Iron Heart Attack Theory” and what Marci and you can do for optimal health.
The Iron Conundrum
For years, cardiologists, like me, have wondered why women don’t seem to get heart attacks prior to menopause. We used to think it was the estrogen that protected women until more recent studies showed that supplemental estrogen may actually increase the risk of a heart attack or stroke.
Could the answer as to why women get heart disease 10 years later than men simply be because their iron levels are much lower? It could be that these regular monthly periods may actually be a blessing for women by allowing them to get rid of extra iron through this monthly blood loss.
To support this theory, studies show that women that have irregular or just occasional periods have a much higher risk of a heart attack. In men, regular blood donors have an 88% lower risk of a heart attack!
Were physicians from the Dark Ages actually onto something with their practice of blood letting? It appears from these, and other studies, that those who regularly lose blood (and iron) from monthly periods or blood donating seem to be protected against heart disease.
Why Do We Need Iron?
If people who regularly lose blood (and iron) are protected against heart attacks, why do we worry so much about getting enough iron in our diet?
It turns out that we need oxygen to survive. Our red blood cells carry all the oxygen we need to the rest of our body. If we don’t have enough iron then we won’t make enough red blood cells and we will become anemic, like Marci.
Like with most things in life, there seems to be a “sweet spot.” Iron is no exception. Too much iron and we are at risk of a heart attack from iron overload. Not enough iron and we become anemic which also puts us at risk of a heart attack.
Who is at risk for iron deficiency?
The main groups of people at risk for iron deficiency in the U.S. are menstruating women and young children. Approximately 10% of women and 15% of young children in the U.S. suffer from iron deficiency. People with ongoing bleeding issues are also at risk for iron deficiency. In these people, they must focus on foods high in iron to avoid becoming anemic.
Who is at risk for iron toxicity?
At the opposite end of the spectrum is a genetic condition called hemochromatosis which affects up to 5% of the population. These people hold onto iron and are at high risk of heart attacks, diabetes, and other conditions.
In addition, even people without hemochromatosis but yet have an “iron overload” state are at risk of heart attacks. For people with iron overload states, they must be very careful to minimize iron in their diets.
Which foods are highest in iron?
Would it surprise you that red meat is one of the highest sources of iron in the diet? Other forms of meat are also high in iron.
With our meat heavy diets in the U.S., our risk of iron deficiency anemia is much lower than most of the world. For us, it usually is not the lack of iron but rather too much iron that may be the problem.
Iron in food comes in two different forms. One is heme iron which is the type of iron found in animal meat. Heme iron is easily absorbed by the body.
The other form of iron, non-heme iron, is the type of iron found in plant-based foods. Non-heme iron is not absorbed as well from the gut.
Plant-based foods high in iron include some vegetables, like spinach, as well as legumes, nuts, and seeds. Interestingly, vitamin C can help you to absorb more iron whereas foods high in calcium tend to block iron absorption.
Could iron overload from excessive red meat cause heart attacks?
Researchers are still not sure why studies have consistently shown that people who eat a lot of red and processed meats seem to be at increased risk for heart attacks. Processed meats include deli meats, hot dogs, pepperoni, sausage, etc.
In the past it was felt that it was the cholesterol and saturated fats in red and processed meats which caused the increased risk of heart attacks. Now, as newer research has shown that dietary cholesterol and saturated fats are not as much of a problem for most people, researchers are looking for other explanations as to why red and processed meat eaters are more likely to have heart attacks.
One possible theory is due to an iron overload state. Studies have consistently shown that iron overload is clearly associated with heart attacks.
How does excess iron cause heart attacks?
It still is not clear how iron overload causes heart attacks. One theory is that iron is directly toxic to the inner layer of our arteries. This theory is supported by a recent Japanese study which showed that by injecting iron intravenously into young healthy men you could cause their arteries to constrict. In addition, the oxidative stress, or “rusting” which comes from excess iron also causes plaque build up within the arteries.
Iron Brain and Alzheimer’s Disease
Iron overload is not just dangerous to the heart but is also dangerous to the brain. For example, iron overload states lead to iron accumulation in the brain which damages the hippocampus. The hippocampus is the part of the brain responsible for our memories.
Indeed, iron overload has now been implicated as a cause of Alzheimer’s Disease. Based on these studies, some researchers now recommend decreasing red and processed meats to protect against Alzheimer’s Disease.
What should Marci do?
In Marci’s case, as she had severe iron-deficiency anemia, she needed to take iron supplements and increase her dietary sources of iron under the direction of her physician. Even though she had a family history of heart disease, severe iron-deficiency anemia can also cause heart attacks as the heart cannot get enough oxygen if the body lacks enough red blood cells to actually carry the oxygen to the heart.
Once her anemia was corrected, her physician appropriately discontinued her iron supplements and she went back to her previous diet which was primarily plant-based. Fortunately, her iron-deficiency anemia has not returned!
How to Avoid Heart Attacks and Dementia from Iron Overload
Iron overload is an increasingly recognized cause of heart attacks and dementia. To protect yourself from the risks of iron overload, let me suggest the following:
1. Get Your Iron and Blood Levels Tested
Your doctor can order some simple blood tests to check your iron levels and to see if you are anemic or not. Based on this information, you can then adjust your diet, if needed, to keep your iron levels where they need to be for optimal health.
2. Minimize Red and Processed Meats
If you are not menstruating or regularly donating blood, you may want to consider minimizing dietary iron by limiting red and processed meats. If your iron levels are too high, or you suffer from hemochromatosis, then you will definitely want to limit meat intake.
Studies have not yet been done to see if the carnivores among us, or those who love meat with every meal, can be protected by donating blood to lower their iron levels. Work with you doctor to determine what the right amount of meat is right for you based on your own individual iron levels.
3. Donate Blood
If you are healthy enough to donate blood then you may want to consider becoming a blood donor. As mentioned, studies show that blood donation decreases the risk of a heart attack by 88%. While blood donation will definitely decrease your iron levels, other possible benefits of blood donation include lowering your blood viscosity and the benefits that come from volunteering.
Blood viscosity is a function of how well blood flows. The more red blood cells you have the more blood tends to clump together which impedes blood flow. Blood donors lower their blood viscosity by donating their red blood cells. Studies have shown that a lower blood viscosity is associated with a lower risk of a heart attack.
There is also the possibility that much of the benefit of blood donation is from the volunteer effect. Unfortunately, only 27% of Americans give of themselves as volunteers. Those that do volunteer experience great benefits. For example, a recent meta-analysis of 40 studies showed that volunteers, who gave at least 15 minutes of their time each week, lived 22% longer and were much happier.
If you are interested in experiencing the tremendous health benefits that come from becoming a blood donor, please speak with your physician to make sure it is safe for you.
What are you doing to keep your iron in the optimal range?
Disclaimer Policy: This website is intended to give general information and does not provide medical advice. This website does not create a doctor-patient relationship between you and Dr. John Day. If you have a medical problem, immediately contact your healthcare provider. Information on this website is not intended to diagnose or treat any condition. Dr. John Day is not responsible for any losses, damages or claims that may result from your medical decisions.