Association between Plasma Homocysteine Concentrations and Extracranial Carotid-Artery Stenosis
This study determined the risk of stenosis (narrowing of the carotid arteries) in relation to homocysteine (amino acid found in the blood) and vitamins concentrations. 1041 elderly subjects (418 men and 623 women aged 67 to 96 years) were included. The results showed that high plasma homocysteine concentrations and low concentrations of folate and vitamin B6 are associated with an increased risk of stenosis of the carotid arteries and, therefore, with an increased risk for stroke. Further details can be found in the study.
As in coronary artery disease, the underlying disease process for cerebrovascular disease –the narrowing of the arteries that supply blood to the brain – is arteriosclerosis. Here too, the process starts with a weakening of the blood vessel walls, most frequently caused by an insufficient dietary intake of vitamins and other micronutrients. This leads to an underproduction of collagen and other reinforcement molecules in the artery walls and to the initiation of a repair process to compensate for the growing instability of these walls. The arteriosclerotic plaques that – with time – narrow the blood flow in the neck (carotid) arteries or brain (cerebral) arteries is essentially an overshooting repair process for the vitamin-deficient artery wall. A stroke occurs when the already narrowed arteries are clogged and the supply of oxygen and nutrients to billions of brain cells is interrupted, causing permanent damage.
Selhub J, Jacques PF, Bostom AG, D'Agostino RB, Wilson PW, Belanger AJ, O'Leary DH, Wolf PA, Schaefer EJ, Rosenberg IH. Association between plasma homocysteine concentrations and extracranial carotid-artery stenosis. N Engl J Med. 1995 Feb 2;332(5):286-91.