Plasma vitamin C modifies the association between hypertension and risk of stroke.
This study from Finland addressed the question of whether there is a correlation between vitamin C levels in the blood, obesity, high blood pressure and the risk of stroke in middle-aged men. For this purpose, a study was conducted with 2,419 men between 42 and 60 years of age over a period of more than 10 years. It was found that study participants with low vitamin C levels in the blood were almost 2.5 times more likely to suffer a stroke than participants with high vitamin C levels. This difference was even more striking with the risk factors hypertension and obesity. In participants with these conditions, the risk of stroke was increased by 2.6 times (low vitamin C + hypertension) or 2.7 times (low vitamin C + overweight). 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.
Kurl S, Tuomainen TP, Laukkanen JA, Nyyssönen K, Lakka T, Sivenius J, Salonen JT. Plasma vitamin C modifies the association between hypertension and risk of stroke. Stroke. 2002 Jun;33(6):1568-73.