Antioxidants may boost heart health and metabolism

04-Jul-2010 - Last updated on 06-Jul-2010 at 08:43 GMT

Long-term supplementation with antioxidants may beneficially effect sugar and fat metabolism, and boost heart health by increasing the flexibility of arteries, says a new study.

Daily supplements of vitamin C, vitamin E, coenzyme Q10 and selenium significantly improved the elasticity of arteries, and levels of HDL cholesterol in people with multiple cardiovascular risk factors, according to findings published in Nutrition & Metabolism.

“This beneficial vascular effect was associated with an improvement in glucose and lipid metabolism as well as significant decrease in blood pressure,” said lead researcher Reuven Zimlichman from Wolfson Medical Center, Israel.

The study involved 70 people with high blood pressure, diabetes, low HDL cholesterol levels, or who were smokers. The average age of the subjects was 62. The participants were randomly assigned to received either a placebo or a daily antioxidant supplement containing vitamin C (1000 mg per day), vitamin E (400 International Units per day), coenzyme Q10 (120 mg per day) and selenium (200 micrograms per day).

Six months later, and the researchers noted that people in the antioxidant group exhibited significant increases in arterial elasticity index, a measure of the flexibility – and therefore the health – of blood vessels. Specifically, the large arterial elasticity index increased from 11 to 12.7 ml/mm Hg x100, while no changes were observed in the placebo group.

Furthermore, both systolic and diastolic blood pressure decreased significantly, with the former dropping from 145.2 to 136.1 mmHg, while the later dropped from 78.4 to 75.0 mmHg, said the researchers.

Significant improvements were also observed in HDL cholesterol levels for the antioxidant group, said the researchers, but not in the placebo group.

How?

Commenting on the potential mechanism, the Israeli researchers note that previous studies have indicated that vitamins C and E may protect DNA from damage, enhance antioxidant defenses and restore the health of the cells lining blood vessels (endothelium). In addition co-Q10 “plays an essential role as an electron carrier in mitochondrial oxidative phosphorylation, improves endothelial dysfunction in diabetic patients”. They also note that selenium, via its role in various antioxidative enzymes, “provides significant protection of the coronary artery endothelium against damage by oxidative stress”.

Limitations

Prof Zimlichman and his co-workers noted that their study had several limitations, including the relatively small number of participants. In addition, they did not measure blood levels of antioxidants, so they have no indication of how well the participants complied with the supplementation.

“Furthermore, since the present study has focused on patients with multiple cardiovascular risk factors, the application of our findings to other patient populations remains uncertain,” they added.

Source: Nutrition & Metabolism
Available free to access here: http://www.nutritionandmetabolism.com/
“Effect of long-term treatment with antioxidants (vitamin C, vitamin E, coenzyme Q10 and selenium) on arterial compliance, humoral factors and inflammatory markers in patients with multiple cardiovascular risk factors”
Authors: M. Shargorodsky, O. Debbi, Z. Matas, R. Zimlichman