[Do vitamins C and E protect against the development of carotid stenosis and cardiovascular disease?].
BACKGROUND
Some observational and randomized, clinical interventional studies have indicated that the antioxidative vitamins C (ascorbic acid) and E (alpha-tocopherol) can reduce intima-media thickness of the carotid arteries. It is, however, not clarified whether these vitamins may have a preventive effect against cardiovascular events.


METHODS
The literature on the effects in relation to several cardiovascular endpoints of vitamins C and E, also used in combination, has been evaluated. The literature has been continuously and systematically collected over many years and supplemented by recent studies retrieved from Medline.


RESULTS
Observational studies including mainly healthy individuals have shown a favourable relationship between intake of vitamins C and E, also taken in combination, and subsequent cardiovascular events. However, most randomized, clinical interventional studies including patients with manifest atherosclerotic disease have not been able to document such a relationship.


CONCLUSIONS
The discrepancy found between observational studies and clinical interventional studies may be due to different study populations (healthy/ill individuals) and differences regarding age, sex, diet, smoking, degree of oxidative stress and other probable confounding factors. The significance of vitamins C and E in preventing cardiovascular disease is in our opinion not yet clarified.
Landmark
Knud
K
Institutt for farmakoterapi, Universitetet i Oslo, Postboks 1065 Blindern, 0316 Oslo. k.h.landmark@labmed.uio.no
Reikvam
Asmund
A
D000975:Antioxidants / Q000008:administration & dosage*; D001205:Ascorbic Acid / Q000008:administration & dosage*; D002318:Cardiovascular Diseases / Q000517:prevention & control*; D016893:Carotid Stenosis / Q000517:prevention & control*; D006801:Humans; D014810:Vitamin E / Q000008:administration & dosage*
D000975:Antioxidants; D014810:Vitamin E; D001205:Ascorbic Acid