Here are a couple of studies this first one is the one I was thinking of.
Too Much Iron Can Increase Men's Risk of Heart Attack
Men with high body iron stores have a two-fold to three-fold increase in risk of developing a first heart attack.
Over 15 years ago, it was suggested that high body iron stores increase the risk of heart attacks. The following study was done in Finland to investigate whether a high iron level in the blood is an independent risk factor for heart attacks. The prospective study population was taken out of 1931 men with no clinical coronary heart disease at baseline. From these, 99 cases who developed a heart attack during an average follow-up period of 6.4 years were matched with 98 control subjects who did not have a heart attack. The findings in this study suggest that men with high body iron stores have a two-fold to three-fold increase in risk of a first heart attack. The association between high iron level and heart attack risk was greater among those who did not take antioxidants or aspirin. Other risk factors were cigarette smoking and serum HDL (high-density lipoprotein, or the "good" cholesterol). It was suggested that the impact of high iron stores in heart attack risk among Finnish men may be greater compared to American men, because of the less popular use of antioxidant vitamin supplements and aspirin in Finland.
Subsequent trials on the benefits of lowering blood iron to prevent heart attacks may be necessary to confirm the above results. [Tuomainen, T., et al. Association Between Body Iron Stores and the Risk of Acute Myocardial Infarction in Men. Circulation, 1998. Vol. 97:1461-1466].
Dutch, Finns Find Too Much Iron Bad For The Heart
WASHINGTON (Reuters) - Researchers said Monday they had found more evidence that a diet too rich in iron can cause heart disease in many people -- another reason to stay away from those juicy steaks.
They found people with one copy of a commonly mutated gene had double the risk of dying from a heart attack or stroke.
The gene is involved in a disease known as hemochromatosis, which allows too much iron to be absorbed from food.
Earlier studies had identified the gene, and doctors knew that people who inherited one copy of the mutated gene from each parent had a much higher risk of heart disease, as well as liver damage and liver cancer.
Writing in the journal Circulation, published by the American Heart Association, two separate groups said they found that people with just one copy of the hemochromatosis gene also had a higher risk.
One in 3,000 people is diagnosed with the condition in the United States. About one in 250 Americans has two copies of the mutated gene and one in 10 has one copy.
While most people store between two and four grams of iron, those with hemochromatosis may accumulate 20 grams or more in their blood's hemoglobin.
There are no real symptoms, but some patients may see their skin turn a rusty orange color from the extra iron in their blood and organs are damaged by the accumulated iron.
Mark Roest and colleagues at Utrecht University Medical School in the Netherlands studied 12,239 middle-aged women. Those who had just one copy of the hemochromatosis gene had double the risk of dying from a heart attack or stroke.
Women who smoked, had high blood pressure and were carriers of the mutated gene had nearly 19 times the risk of heart attack and stroke death compared to non-smokers with normal blood pressure who did not have the mutation, Roest reported.
``This is the first large study to find a significant association between women who are carriers of the gene and cardiovascular disease,'' Roest said in a statement.
He said the study also supported the idea that women are protected from heart disease before menopause because they lose iron every month during menstruation.
Dr. Jukka Salonen and colleagues at the University of Kuopio in Finland had earlier found that regularly giving blood reduced the risk of heart disease.
In a second study in Circulation, they checked for the hemochromatosis gene among 1,150 Finnish men. ``Carriers of the gene have more than twice the risk for a heart attack compared to non-carriers,'' they wrote.
``Based on what we know now, a strong case could be made for recommending blood donation as a way to lower iron levels, thus lowering heart attack risk,'' Dr. Jerome Sullivan of the University of Florida in Gainesville said in a commentary.
Red meat is rich in iron and Americans were once urged to eat plenty to get enough iron. But the average diet now provides a more than adequate iron intake, and red meat is also high in saturated fat, which is a major cause of heart disease.
Japanese heart-disease study focuses on role of iron
October 26, 2000
Web posted at: 9:48 AM EDT (1348 GMT)
WASHINGTON (Reuters) - Japanese researchers said Wednesday they may have figured out why high iron levels in the blood are linked with heart disease, and it may all boil down to rust.
They found evidence that iron can increase so-called oxidative stress on the lining of blood vessels. Oxidation is the same process seen in iron outside the body when it rusts.
This could mean that the Western diet, rich in red meat, causes heart disease not only because it has so much fat, but because it is too rich in iron, Matsuoka said.
"There have been a number of studies that suggest iron stores are closely linked to the incidence of (heart attack) and coronary artery disease," Dr. Hidehiro Matsuoka, chief of the division of hypertension at the Kurume Medical School in Kurume, Japan, who led the research, said in an interview.
For instance, men who regularly donate blood have a lower risk of heart disease, and pre-menopausal women, who regularly lose blood, and thus iron, through menstruation, also have a lower risk of heart disease.
"Many scientists attribute the significantly low risk of cardiovascular disease among pre-menopausal women to the protective effects of estrogen," Matsuoka said.
"But the hypothesis has been raised that the iron depletion associated with menstruation also protects against heart disease."
And biochemical studies have shown that iron helps generate free radicals -- the little charged particles that can cause damage to cells in the body.
Reporting to a conference of the American Heart Association's Council for High Blood Pressure Research, Matsuoka said his team decided to see if they could link these two sets of findings.
They looked at iron's effects on the endothelium -- the layer of cells that lines blood vessels and which is intimately linked with heart and artery disease.
In the first study of 10 healthy men, they overloaded them with iron intravenously and then looked at their blood vessels using ultrasound.
The iron overload raised levels of the chemical malondialdehyde, a marker of oxidation and of impaired endothelial function. Then they used a drug to lower iron levels in 10 healthy male smokers, and found iron removal lowered levels of the chemical and made the endothelium work better.
According to the American Heart Association, the Japanese study is the first to show that iron loading hurts the lining of the blood vessels.
"Our study shows that we should recognize iron as a risk factor for atherosclerosis and understand the need to control our body iron levels to prevent cardiovascular disease," Matsuoka said in a statement.
He said he believed that iron somehow interferes with nitric oxide, a chemical that relaxes blood vessel walls. allowing the blood to flow more freely.
He believes that doctors should measure endothelial function as part of a standard physical exam, just as blood pressure is now measured. The test is simple and uses harmless ultrasound, Matsuoka said.
"It only takes 30 minutes," he said.
He also noted that kidney dialysis patients, because they are anemic, often get intravenous iron, and that they also have very high rates of heart disease. It could be that giving iron intravenously stresses the arteries.
Taking iron orally is safer, Matsuoka said, and kidney dialysis patients should be aware of the danger.
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Unless they're so profoundly depleted that you finally become anemic as a result.
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