Japanese scientists report that regular consumption of the powerful antioxidant vitamin C may help reverse vasoconstriction, or narrowing of the arteries, in smokers, specifically by targeting the impaired endothelial function that causes this condition.1
Smoking boosts oxidative stress and produces vasoconstriction,2 which may increase the risk of related conditions such as coronary heart disease, heart attack, aortic aneurysm, and stroke.3 The endothelium, a layer of cells lining the interior of blood vessels, produces coronary-related compounds that regulate vascular tone, such as nitric oxide.4
To test vitamin C’s effects on coronary health, researchers at Chiba University, Japan, recruited 25 patients, 13 of whom were otherwise healthy smokers and 12 who were nonsmokers. Using a monitoring test known as transthoracic Doppler echocardiography, the team evaluated coronary blood flow in each patient, both while at rest and during moments of increased blood flow. Blood flow and levels of vitamin C were measured at baseline and then at two and four hours following intake of vitamin C.
At the study’s onset, blood flow was greatly increased in nonsmokers compared to smokers. However, at the study’s end, the smokers’ blood flow rates had increased significantly, while the nonsmokers’ blood flow was unchanged. The study authors concluded that vitamin C helps relieve the vasoconstriction that can occur in chronic smokers.
—Linda M. Smith, RN