Postprandial antioxidant effect of the Mediterranean diet supplemented with coenzyme Q10 in elderly men and women

Abstract

Postprandial oxidative stress is characterized by an increased susceptibility of the organism towards oxidative damage after consumption of a meal rich in lipids and/or carbohydrates. We have investigated whether the quality of dietary fat alters postprandial cellular oxidative stress and whether the supplementation with coenzyme Q(10) (CoQ) lowers postprandial oxidative stress in an elderly population. In this randomized crossover study, 20 participants were assigned to receive three isocaloric diets for periods of 4 week each: (1) Mediterranean diet supplemented with CoQ (Med+CoQ diet), (2) Mediterranean diet (Med diet), and (3) saturated fatty acid-rich diet (SFA diet). After a 12-h fast, the volunteers consumed a breakfast with a fat composition similar to that consumed in each of the diets. CoQ, lipid peroxides (LPO), oxidized low-density lipoprotein (oxLDL), protein carbonyl (PC), total nitrite, nitrotyrosine plasma levels, catalase, superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities and ischemic reactive hyperaemia (IRH) were determined. Med diet produced a lower postprandial GPx activity and a lower decrease in total nitrite level compared to the SFA diet. Med and Med+CoQ diets induced a higher postprandial increase in IRH and a lower postprandial LPO, oxLDL, and nitrotyrosine plasma levels than the SFA diet. Moreover, the Med+CoQ diet produced a lower postprandial decrease in total nitrite and a greater decrease in PC levels compared to the other two diets and lower SOD, CAT, and GPx activities than the SFA diet.In conclusion, Med diet reduces postprandial oxidative stress by reducing processes of cellular oxidation and increases the action of the antioxidant system in elderly persons and the administration of CoQ further improves this redox balance.

Fig. 1

Differences in A IRH change, B total nitrite levels in plasma, and C plasma PC levels according to the type of fat consumed during the postprandial phase. Differences in the parameter levels between time 0 and time 2 are shown as ∆ 2 h (value of time 2 minus value of time 0), and between time 0 and time 4 are shown as ∆ 4 h (value of time 4 minus value of time 0). Data were analyzed using ANOVA for repeated measures. All values represent the mean ± standard errors (SE). Bars with different superscript letters depict statistically significantly differences (p < 0.05). p1, diet effect; p2, time effect; p3, diet × time interaction

Fig. 2

Postprandial plasma levels in A total CoQ and B LPO according to the type of fat significantly differences (p < 0.05). p1, diet effect; p2, time effect; p3, diet × time interaction