From foodconsumer.org
High vitamin C in the blood means lower stroke risk
By David Liu, Ph. D.
Apr 8, 2008 - 9:14:55 AM
TUESDAY April 8, 2008 (foodconsumer.org) -- Elevated blood levels of vitamin C may reduce the risk of stroke by 42 percent, suggests a large European study of 20,649 men and women.
Phyo Myint from the University of Cambridge, coauthor of the study, said blood levels of vitamin C could serve as a biological marker of lifestyle used to identify people at high risk of stroke. Increased levels of the vitamin were associated with increased intake of fruit and vegetables.
Vitamin C may also biochemically affect stroke risk, according to Myint.
The study, known as the European Prospective Investigation into Cancer, was published in the January 2008 issue of American Journal of Clinical Nutrition.
For the study, Myint and colleagues followed the participants for 9.5 years and identified 448 cases of strokes. Blood samples were analyzed for the level of vitamin C and dietary habit and lifestyle were surveyed at the start of the study.
Those who had highest blood levels of vitamin C, greater than 66 micromoles per liter, had a 42% reduced risk of stroke than those who had the lowest level, less than 41 micromoles per liter.
The association was observed after adjusting potential confounding factors including age, sex, smoking habits, alcohol consumption, blood pressure, cholesterols, BMI, physical activity and use of supplements.
When those who took vitamin C supplements were excluded, the correlation between vitamin C levels in the blood and risk of stroke was the same, meaning that the lower risk of stroke may be associated with vitamin C rich fruit and vegetables.
It is unknown whether vitamin C supplements may play a role in the reduction of stroke risk.
The study suggests that five to seven servings a day of fruit and vegetables, which offer about 200 mg of vitamin C, is good for cardiovascular health.