Evaluation of lipid oxidation after ingestion of bakery products enriched with phytosterols, β-carotene and α-tocopherol

Background & aims: The aim of this study was to investigate the effect of the consumption of croissants and magdalenas (Spanish muffins), enriched with sterol esters, α-tocopherol and β-carotene, on plasma lipid peroxidation. TBA and conjugated dienes were used as markers of lipid peroxidation. Methods: The study was made to a population without changes in their diet or lifestyle, and based on a randomized double-blind controlled repeated measures design. The sample size was 57. During 8 weeks, the subjects of the control group (29) received two daily pieces (standard croissant and muffin), whereas those of the experimental group (28) received the same products, but enriched with sterol-esters, α-tocopherol and β-carotene. Results: The treatment has a positive effect on TBA value for control group and that given to experimental group has negative effect. The mean difference between two groups is 3.16 (P=0.044). Also TBA was found to be significantly correlated with HDL-, LDL-cholesterol and α-tocopherol, both before and after treatment, but TBA was only significantly correlated with β-carotene before treatment. Finally, the effects on LDL-cholesterol, α-tocopherol and TBA presented similar correlation matrices in the two groups, most correlation coefficients being significant at group level, in spite of the low sample sizes, revealing the association between treatment effects.