Positive Health Online

Abstract

AZEN and colleagues, Statistical Consultation and Research Center, University of Southern California, Los Angeles USA write that experimental, epidemiological and clinical evidence is accumulating which demonstrates an association between anti-oxidant vitamin intake and reduced risk of coronary heart disease. The authors, using data from the Cholesterol Lowering Atherosclerosis Study (CLAS) studied the association of supplementary antioxidant vitamin intake upon the progression rate of early preintrusive atherosclerosis. @m: Nonsmoking 4059 year old men with previous coronary artery bypass graft surgery were randomised to either colestipol (a lipid lowering drug)/niacin plus diet or placebo plus diet treatment groups. The rate of progression of early preintrusive atherosclerosis was determined in 146 men using high-resolution ultrasound quantification of the distal common carotid artery far wall intima-media thickness (IMT). From the nutritional supplement database, 22 men had an on-trial average supplementary vitamin E intake of at least 100 IU per days (high users) and 29 men had an average on-trial supplementary vitamin C intake of at least 250 mg per day (high users). @r: When compared with low vitamin E users, high supplementary vitamin E users had less carotid IMT progression, within the placebo group. There was no effect within the drug group of vitamin E and no effect of vitamin C within either the drug of placebo group. @c: Supplementary vitamin E appears to be effective in reducing the progression of atherosclerosis in men not treated with lipid-lowering drugs when the process was still confined to the arterial wall.

Background

Methodology

Results

Conclusion

References

Azen SP et al. Effect of supplementary antioxidant vitamin intake on carotid arterial wall intima-media thickness in a controlled clinical trial of cholesterol lowering. Circulation. 94(10): 236972. Nov 15 1996.

Comment

The levels of antioxidant vitamins taken by the high users vitamin E (100 IU) and vitamin C (250 mg) are fairly low. It is not surprising that no effect was seen with vitamin C at merely 250 mg per day; probably it would be necessary to raise the intake of vitamin C to at least 5001000 mg per day. Likewise the vitamin E levels should have been at least 200400 IU per day. The results would probably be even more impressive with higher antioxidant intake.