Effect of antioxidant‐enriched foods on plasma Coenzyme Q 10 and total antioxidant capacity

Twenty healthy subjects integrated their diet with two types of products sequentially: In the first phase (first 14 days), the volunteers were given the following food items not supplemented with vitamin E (vit. E) or Coenzyme Q 10 (CoQ 10 ): breakfast, 250 mL skimmed milk; mid‐morning snack, 330 mL fruit juice; mid‐afternoon snack, low‐fat yogurt 125 g; after dinner, low‐fat dessert 110 g. In the second phase, from day 14 to day 35, the same items were added with vit. E and CoQ 10 (a total daily supplementation of 19.4 mg CoQ 10 and 13.7 mg vit.E). After taking the supplemented products for 2 weeks, plasma CoQ 10 reached 1.30 µg/mL, nearly twice the initial values. These levels further increased after 3 weeks of supplementation. Vit. E levels significantly ( p  <0.001) increased only after 3 weeks of supplementation, reaching 7.9 ± 2.8 µg/mL, 39% more than the initial value. The total plasma fatty acid pattern did not change substantially throughout the study. The increase of the total antioxidant capacity of plasma was significant ( p  <0.001) for days 28 and 35, with values close to 0.24 ± 0.09 mM Trolox (a nearly 60% increase).