Plain language summary
Olive oil has been shown to be protective against heart disease and cancer. This small trial aimed to look at changes in gene expression after consuming olive oil. The trial involved six healthy, young adult males who consumed 50ml virgin olive oil, while following a low-phenolic diet. Gene expression was measured at baseline and six hours after olive oil consumption. Following olive oil consumption several changes in gene expression were observed that were related to known protective effects, such as reduced inflammation, increased high density lipoprotein (HDL) cholesterol and improved glucose and insulin sensitivity. The authors summarised that the protective effects linked with olive oil consumption could be achieved through gene expression. However, it was acknowledged that a limitation of the trial was the lack of a control group.
Abstract
Olive oil consumption is protective against risk factors for cardiovascular and cancer diseases. A nutrigenomic approach was performed to assess whether changes in gene expression could occur in human peripheral blood mononuclear cells after oli ve oil ingestion at postprandial state. Six healthy male volunteers ingested, at fasting state, 50 ml of olive oil. Prior to intervention a 1-week washout period with a controlled diet and sunflower oil as the only source of fat was followed. During the 3 days before and on the intervention day, a very low-phenolic compound diet was followed. At baseline (0 h) and at post-ingestion (6 h), total RNA was isolated and gene expression (29,082 genes) was evaluated by microarray. From microarray data, nutrient-gene interactions were observed in genes related to metabolism, cellular processes, cancer, and atherosclerosis (e.g. USP48 by 2.16; OGT by 1.68-fold change) and associated processes such as inflammation (e.g. AKAP13 by 2.30; IL-10 by 1.66-fold change) and DNA damage (e.g. DCLRE1C by 1.47; POLK by 1.44- fold change). When results obtained by microarray were verified by qRT-PCR in nine genes, full concordance was achieved only in the case of up-regulated genes. Changes were observed at a real-life dose of olive oil, as it is daily consumed in some Mediterranean areas. Our results support the hypothesis that postprandial protective changes related to olive oil consumption could be mediated through gene expression changes.
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