Review of homocysteine and the risk of heart disease
Researchers from Ochsner Medical Center in New Orleans, Louisiana have reviewed homocysteine and concluded that it’s “one facet of a complex metabolic puzzle — a veritable Rubik’s cube — that promotes atherosclerosis.”
Here’s what we know.
- Elevated levels of homocysteine accelerate development of atherosclerotic lesions in animal models.
- Impairs relaxation of blood vessels in humans.
Causes of high homocysteine blood levels
- Genetic defects in enzymes involved in homocysteine metabolism
- Nutritional deficiencies in vitamins (folate, vitamin B12, and vitamin B6)
The cardiovascular disease connection
- Studies show homocysteine is a risk factor for stroke, coronary heart disease, venous thromboembolism, and death.
- Reanalysis of all the data reconfirmed these findings and showed that the risk for coronary heart disease was increased approximately 20% for each 5 mcmol/L increase in homocysteine blood levels.
Lowering homocysteine levels
- Best accomplished by taking B vitamins (folate, vitamins B6 and B12).
- Methionine restriction and exercise training result in modest lowering.
The Vitamin Intervention for Stroke Prevention (VISP) trial
- Designed to determine if lowering homocysteine levels by taking B vitamins might reduce the risk of cardiovascular disease.
- Homocysteine levels became lower with treatment, but there was no effect on cardiovascular disease.
The bottom line?
More chapters will be written in this story. However, based on what we know today, the authors concluded, “Elevated homocysteine levels are associated with an increased risk of cardiovascular events, but B vitamins may not provide a preventive benefit in patients with mild homocysteinemia.”
11/6/08 18:38 JR
