Human circulation system, eps10A study that was published in Nutrition (Volume 29, Issue 1 , Pages 71-75, January 2013) looked at the blood vessel health of 65 firefighters. Supplementation with aged garlic extract (300 mg/day) and  CoQ10 (30 mg/day) for a period of one year.  The authors found that the combination of the two supplements significantly improved the elasticity of the blood vessels and may be effective in preventing atherosclerosis.