Too much iron, alcohol a bad mix for the heart

Women who like a beer with their steak may want to exercise moderation, if new research findings are correct.

In a study of more than 34,000 U.S. women between the ages of 55 and 69, researchers found that the combination of regular drinking and high iron intake from meat was associated with a heightened risk of death from cardiovascular disease.

The theory is that the alcohol triggers the release of iron from the proteins in the body where the mineral is normally stored. While iron is an essential nutrient, it's suspected that significantly high levels in the body contribute to the generation of reactive oxygen species - molecules that can damage body cells and, over time, may promote heart disease, cancer and other ills.

The new findings give weight to the belief that such oxidative stress plays an important role in the development of cardiovascular disease, according to study co-author Dr. David R. Jacobs Jr., a professor of epidemiology at the University of Minnesota in Minneapolis.

In keeping with that, Jacobs and his colleagues also found that women who drank regularly but had a relatively higher zinc intake showed a decreased risk of dying from Heart disease or Stroke.

A mineral found in meat, fortified cereals, beans and nuts, zinc is thought to act as an antioxidant - meaning it may quash reactive oxygen species. The recommended daily intake for zinc is 8 milligrams (mg) for women. In this study, the group with the highest zinc intake typically consumed 20 mg per day.

The findings, published in the American Journal of Clinical Nutrition, are based on data from women who took part in a long-term study of the health effects of diet and other lifestyle factors. At the study's start, participants filled out detailed questionnaires on their eating habits over the past year and gave information on other health factors, such as exercise habits and smoking.

Over the next 15 years, nearly 1,800 women died of cardiovascular disease or Stroke. Overall, iron intake was not related to the risk of dying from these diseases, but when Jacobs and his colleagues focused on women who drank regularly, a different picture emerged.

Among women who drank roughly a drink a day or more, the risk of dying from cardiovascular disease rose in tandem with a woman's average intake of heme iron, the form of iron consumed through meat. Among these regular drinkers, those who ate the most heme iron had more than twice the risk of cardiovascular death as those who ate the least.

Iron from supplements was not strongly related to cardiovascular disease, while nonheme iron - found in plant sources such as beans and grains and in fortified cereals - showed a more complicated relationship to cardiovascular disease. Among regular drinkers, those who ate moderate levels of plant-based iron had a lower risk of cardiovascular death than both women who ate little nonheme iron and those who ate the most.