Vitamin C and stroke:
Vitamin C levels, cardiovascular disease, and stroke:
In over 20,000 men and women age 40-79, it was found by calculation of relative risk that the highest quartiles of plasma vitamin C levels had a 42% lower risk of stroke than the lowest quartile of plasma vitamin C levels (91). Chen, GC et al performed a meta-analysis, and found 11 studies that showed a higher vitamin C intake compared to a lower vitamin C intake was associated with a lower risk of stroke (92).
Vitamin C levels, risk of cardiovascular disease, and mortality:
An analysis was conducted on 19,496 men and women, ages 45 to 79, in the U.K. The participants’ blood was tested for ascorbic acid (a form of vitamin C) and they were placed in five groups (quintiles) according to their serum ascorbic acid levels. Men and women were tracked separately. The researchers observed how many people died of cardiovascular disease, ischemic heart disease, cancer, and all causes in each of the blood ascorbic acid quintiles. In every case (except for women at risk of cancer), death rates were significantly lower among those with higher blood ascorbic acid levels. Those with the highest ascorbic acid levels compared to the lowest levels had half the risk of dying from ischemic heart disease, cardiovascular disease, and all causes combined. Additionally, a 20 micromol/L increase in blood ascorbic acid concentration, the same as a 50 g per day increase in fruit and vegetable intake, was associated with about a 20% reduction in risk of all-cause mortality. (73)