Lipophilic antioxidants and polyunsaturated fatty acids in lipoprotein classes: distribution and interaction

OBJECTIVE: To study the lipoprotein distribution of supplemented coenzyme Q10 (CoQ10), vitamin E, and polyunsaturated fatty acids (PUFA). DESIGN: Balanced three-period crossover study. SETTING: University research unit. SUBJECTS: Eighteen apparently healthy free-living non-smoking volunteers (nine women, nine men), mean age 26 +/- 3 y, recruited among the university students; no dropouts. INTERVENTIONS: Three supplementation periods of 10 days: 100 mg/day CoQ10, 350 mg/day D-alpha-tocopherol, and 2 g/day concentrated fish oil. Fasting venous blood samples were collected twice before the first period and then after each period. Plasma and isolated lipoproteins were analysed for cholesterol, triacylglycerol, alpha- and gamma-tocopherol, CoQ10, and fatty acid composition. RESULTS: Significant (P < 0.05) increase in CoQ10 and alpha-tocopherol occurred in all lipoprotein classes after supplementation. CoQ10 was primarily incorporated into low-density lipoprotein (LDL). alpha-tocopherol and fish oil n-3 PUFAs had similar patterns. They were equally distributed between LDL and high-density lipoprotein (HDL), with a smaller part in VLDL. The total sum of PUFA was unchanged following all supplementations, but fish oil increased the amount of n-3 fatty acids at the expense of n-6 fatty acids. CONCLUSION: Lipoprotein distribution of CoQ10 is markedly different from that of alpha-tocopherol, suggesting that they may be metabolised by distinct routes. alpha-Tocopherol is distributed similarly to n-3 fatty acids, thus providing protection on location for the oxidatively labile PUFAs.