Studies show homocysteine levels may be related to heart disease
Cholesterol has been a topic of conservation when it comes to heart disease for some time now. Over time we have learned much about cholesterol. In fact, there is even bad cholesterol (low-density lipoproteins) and good cholesterol (high-density lipoproteins). The bad cholesterol sticks to your artery walls and contributes to plaque formation. We try to engage in an active lifestyle and eat appropriately to maintain healthy levels of both types of cholesterol.
But, have you heard of homocysteine? This is an amino acid that has recently been associated with heart disease in several research studies. A few weeks ago I heard Dr. Kenneth Cooper, of the renowned Cooper's Clinic in Dallas, Texas, speak and he referred to homocysteine as "the cholesterol of the next century." Some medical experts believe that people will eventually have their homocysteine levels checked routinely as part of a coronary-risk profile, like heart rate, blood pressure, cholesterol levels and such.
An earlier research study in 1968 identified a relationship between homocysteine and heart disease among children with a genetic disorder involving high homocysteine levels. However, the findings by Dr. Kilmer McCully of Harvard Medical School were mostly ignored until the mid 1980s. Since that time a number of studies have also demonstrated a relationship between homocysteine levels and heart disease. It appears that high homocysteine levels are associated with thickening and narrowing of the arteries, high levels of bad cholesterol and blood clots. However, there have been some studies that did not show such a relationship.
Research has only identified this relationship and has not explained the connection between homocysteine and heart disease. These correlational studies can only identify relationships and cannot establish a "cause and effect" pattern between homocysteine levels and heart disease.
Researchers do not know about the effect of exercise on homocysteine levels or even if reducing your homocysteine levels reduces your chance of heart disease. It has been shown that B-vitamins can reduce homocysteine levels. These include vitamin B-6, vitamin B-12 and folate. Folate is the natural form occurring in foods, whereas you may be more familiar with folic acid, the synthetic form of folate. Some experts are suggesting that people who are at risk for heart disease increase their intake of these vitamins.
Currently there are no general recommendations for homocysteine testing. The American Heart Association does not recommend widespread testing but does state that homocysteine testing might be useful for people with high coronary risk factors. Homocysteine is measured based on its molecular weight within the blood. The unit of measurement is micromols. More than 15 micromols is considered high risk for heart disease.
There will be much more research in the coming years to address all the questions concerning homocysteine. In particular the effect of diet, exercise and supplements on homocysteine will be studied and better insight into the appropriate homocysteine level will be identified. Most importantly, researchers need to better understand the relationship between homocysteine levels and heart disease. As researchers learn more, new recommendations concerning homocysteine levels are probably on the horizon.
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(EDITOR'S NOTE: Jimmy H. Ishee is associate dean of the College of Health and Applied Sciences at the University of Central Arkansas. His column on fitness appears each Tuesday in the Features section of the Log Cabin Democrat.)