By O’Shaughnessy’s News Service
People in Greece, Southern Italy, and Spain have lower rates of colon, breast, prostate, and ovarian cancer than Northern Europeans. This is attributed to differences in diet. In the Mediterranean diet, the primary source of fat is extra-virgin olive oil (EVOO); the Northerners use butter and lard.
The EVOO benefit is dramatic —an almost 50% lower rate of colon cancer, for example. Extra-virginity is important because the polyphenols in freshly pressed olive oil degrade with aging and re-processing.
Andrea Di Francesco and colleagues in Mauro Maccarrone’s lab have been studying EVOO’s mechanism of action. Exposing colon cancer cells (Caco-2) to EVOO or an extract of its phenolic compounds resulted in “a selective increase in CB1 gene expression” and “inhibited proliferation of Caco-2 cells and arrested their cycle.”
The researchers also fed healthy rats with a standard diet and an EVOO supplement, then looked for changes in cells lining the colon. Ten days of EVOO supplement led to “a significant increase in CB1 gene expression levels in colon.”
This was due to “epigentic mechanisms.” As explained by Maccarrone, “We found that CB1 is less expressed in cancer cells because it is more methylated at the promoter level. The gene is there, but it is not expressed.”
A “promoter” is a region of DNA that initiates transcription of a particular gene. It’s where DNA is turned into RNA. Methylation refers to the addition of methyl groups (CH3) to a molecule.
Catalyzed by specific enzymes, methylation is involved in regulating gene expression and protein function. In normal cells, the promoter region is not highly methylated and the gene is expressed. But in cancer cells, the promoter region is highly methylated and the gene is silenced. More methylation of the gene means less CB1 expression and weaker endocannabinoid tone.
Aberrant methylation appears to be a precipitating factor in the development of cancer. But methylation doesn’t just happen on its own. If a gene is inappropriately methylated, then some process in the body is causing this to happen.
Psychological trauma and high level activation of the body’s stress system, especially in early childhood, are known to trigger abnormal methylation that changes DNA and disables genes. So, too, in animals. There have been studies that show differences in maternal care during the first six days of a rat’s life result in different methylation patterns in promoter regions, thereby influencing gene expression.
Poor diet and exposure to environmental toxins can also skew gene expression.
“Attack of the Fastidiosi”
No sooner do we begin to appreciate the health benefits of extra virgin olive oil, than a bacterium starts destroying Italy’s best trees. Jim Yardley’s piece in the NY Times May 11 is scarier than any of those Hollywood movie ads we’re bombarded with while trying to watch the NBA playoffs. Here’s an excerpt:
Scientists estimate that one million olive trees in the peninsula, known as the Salento, are infected with the bacterium, Xylella fastidiosa, a figure that could rise rapidly.