HOMOCYSTEINE:
The Main Cause of Heart Disease?

In 1969, heart researcher Kilmer S. McCully, M.D., published an unorthodox conclusion in the American Journal of Pathology regarding a new possible cause of heart disease. This move soon cost him his job at Harvard University, he says.

Dr. McCully proposed that a substance called homocysteine could, when allowed to accumulate to toxic levels, degenerate arteries and produce heart disease. Homocysteine, an amino acid, is a normal by-product of protein metabolism (specifically, of the amino acid methionine) which does not create a problem when present in small amounts.

However, Dr. McCully observed that children with elevated levels of homocysteine showed signs of blood vessel degeneration similar to these observed in middle-aged adults with heart disease. He next demonstrated that when rabbits were injected with homocysteine, they developed arterial plaques within three to eight weeks. Homocysteine apparently curtails the ability of blood vessels to expand, keeping them restricted and narrow. It accomplishes this by increasing connective tissue growth and by degenerating the elastic tissue in the arterial walls, says Dr. McCully.

Dr. McCully argued that high-protein diets, more than fats and cholesterol, seem to be a prime cause of heart disease. After publication of his novel theory, subsequently backed by considerable clinical support, Harvard denied him tenure, and effectively fired him.

The evidence continues to mount in support of Dr. McCully's homocysteine theory. In 1992, researchers at Harvard University School of Public Health showed that men with homocysteine levels only 12% higher than average had 3.4 times greater risk of heart attack than those with normal levels. Also that year, the European Journal of Clinical Investigation showed that 40% of stroke victims have elevated homocysteine levels compared to only 6% of controls.

The Journal of the American Medical Association (1995) reviewed 209 studies linking homocysteine with heart disease and concluded that homocysteine represents a strong independent risk factor for stroke even after adjustment of other risk factors.

According to Dr. McCully, heart disease is attributed to "abnormal processing of protein in the body because of deficiencies of B vitamins in the diet." It is this B-vitamin deficiency which allows homocysteine, normally converted to a harmless substance, to accumulate to dangerous levels. "Protein intoxication," characterized by excess homocysteine, then starts damaging the cells and tissues of arteries, "setting in motion the many processes that lead to loss of elasticity, hardening and calcification, narrowing of the lumen (arterial passageway), and formation of blood clots within arteries."

Elevated homocysteine has the potential of displacing high cholesterol levels as the major dietary factor in heart disease. A German study (1991) looked at the coronary arteries of 163 males with chest pain and concluded that the arterial narrowing was due more to blood levels of homocysteine than to cholesterol. In 1997, Dr. McCully declared: "Elevated blood homocysteine is estimated to account for at least 10% of the risk of coronary heart disease in the U.S. population."

An effective way to lower homocysteine is through vitamin B6, often combined with folic acid and vitamin B12, Dr. McCully further discovered. Dr. McCully generally recommends 3-3.5 mg of vitamin B6, 350-400 mcg daily of folic acid, and at least 3 mcg daily of vitamin B12. According to Mark Nehler, M.D., and colleagues at Oregon Health Sciences University in Portland, at least 50,000 annual deaths from coronary disease could be prevented yearly by supplementation with oral folate (folic acid), based on his analysis of the patient outcomes (and mortalities) of other published studies. SOURCES- Kilmer S. McCully, M.D., The Homocysteine Revolution: Medicine for the New Millennium, Keats Publishing, Inc. (1997), 27 Pine Street, Box 876, New Canaan, CT 06840 (800) 858-7014.

To reach Kilmer McCully, M.D., contact: Veterans' Affairs Medical Center, 830 Chalkstone Ave., PL & M (113), Providence, RI 02908; fax 401-457-3069.

(Reprint, Alternative Medicine Digest, Issue 20)

Copyright © 1996. The Light Party.