19688
document
Folate levels determine effect of antioxidant supplementation on micronuclei in subjects with cardiovascular risk . We have investigated the effect of modest supplementation with alpha-tocopherol ( 100 mg/day ) , beta-carotene ( 6 mg/day ) , vitamin C ( 100 mg/day ) and selenium ( 50 microg/day ) on oxidative stress and chromosomal damage , and the influence of methylenetetrahydrofolate reductase ( MTHFR ) genotype on these end-points . Subjects were two groups of middle-aged men differing in cardiovascular risk ; 46 survivors of myocardial infarction before age 50 and 60 healthy controls . They were randomly divided into equal groups to receive antioxidants or placebo for 12 weeks . Twenty-eight patients and 58 controls completed the intervention . Micronucleus levels in peripheral lymphocytes and changes seen after intervention were studied in relation to the MTHFR C677T genotype , basal homocysteine and plasma folate levels . Ferric reducing ability of plasma and concentration of malondialdehyde were measured to assess the antioxidant effect of supplementation . There was no association of micronuclei with folate , homocysteine or malondialdehyde levels before supplementation . Micronucleus frequencies and plasma folate levels did not vary significantly with MTHFR genotype . Homocysteine levels in subjects with the TT variant genotype were significantly higher compared with CT or CC ( P = 0.001 ) , especially in subjects with low folate ( P = 0.012 ) . In the placebo control group an increase in micronuclei ( P = 0.04 ) was detected at the end of the intervention period . This effect was not seen in the supplemented group . In antioxidant-supplemented myocardial infarction survivors we found an increase in the ferric reducing ability of plasma ( P < 0.001 ) and a decrease in malondialdehyde ( P = 0.001 ) . Micronucleus frequency showed a decrease , strongest in subjects with normal folate levels ( P = 0.015 ) . In subjects with low folate levels , a high correlation was found between micronuclei after supplementation and homocysteine , both before ( r = 0.979 , P = 0.002 ) and after supplementation ( r = 0.922 , P = 0.009 ) . Thus , folate deficiency may amplify the effect of other risk factors such as elevated homocysteine levels or variant MTHFR genotype , as well as influencing the ability of antioxidant supplementation to protect against genetic damage .
19689
Intervention_Pharmacological
antioxidant supplementation
19690
Intervention_Pharmacological
supplementation with alpha-tocopherol
19691
Intervention_Pharmacological
beta-carotene
19692
Intervention_Pharmacological
vitamin C
19693
Intervention_Pharmacological
selenium
19694
Intervention_Pharmacological
antioxidants
19695
Intervention_Control
placebo
19696
Intervention_Pharmacological
supplementation
19697
Intervention_Pharmacological
antioxidant supplementation
19698
Outcome_Physical
micronuclei
19699
Outcome_Physical
Micronucleus levels in peripheral lymphocytes and changes seen after intervention were studied in relation to the MTHFR C677T genotype , basal homocysteine and plasma folate levels . Ferric reducing ability of plasma and concentration of malondialdehyde were measured to assess the antioxidant effect of supplementation .
19700
Outcome_Physical
Micronucleus frequencies
19701
Outcome_Physical
plasma folate levels
19702
Outcome_Physical
Homocysteine levels
19703
Outcome_Physical
micronuclei
19704
Outcome_Physical
ferric reducing ability of plasma
19705
Outcome_Physical
decrease in malondialdehyde
19706
Outcome_Physical
Micronucleus frequency
19707
Outcome_Physical
micronuclei