Dietary Cholesterol Shown to Increase Colon Cancer Risk
Nutrition / Natural Medicine Update No. 81 (January 29, 2018)
with Dr. James Meschino
Research Topic: Dietary Cholesterol Shown to Increase Colon Cancer Risk
Source: Journal Cell Stem Cell (January 2018)
For many years studies have suggested that a high animal fat diet (with the exception of fish), has been linked to higher rates of colon cancer. Researchers have discovered mechanisms that explain how higher levels of animal fat ingestion increase colon cancer risk. As an example, high animal fat consumption increases the production of secondary sterols and creates alterations in the gut microflora that have been shown to promote colon cancer development.
But what about the cholesterol found in these high-fat animal foods? Studies suggest that a higher cholesterol intake may also directly increases colon cancer risk. So, the study published in the journal Cell Stem Cell in January 2018 was a ground-breaking study that showed the exact mechanism by which dietary cholesterol increases cancer development in the colon. As one of the researchers stated, “while the connection between dietary cholesterol and colon cancer is well established, no one has previously explained the mechanism behind it.”
Using an animal model, the study showed that higher intakes of dietary cholesterol increased the concentration of cholesterol that accumulated in the outer skin (the cell membrane) of cells that line the colon. In turn, the high levels of cholesterol in the outer skin of the intestinal cells acted like a triggering signal for the cells to divide at a faster and faster rate. As the cells divided faster they made more genetic mistakes that transformed normal cells into colon cancer cells. In fact, the tumor cell formation was more than 100-fold under the influence of high dietary cholesterol.
The researchers explained it this way, “as the animals’ cholesterol levels rose, their cells divided more rapidly, causing the tissue lining their guts to expand and their intestines to lengthen. These changes significantly sped up the rate of tumor formation in their colons”. Colon cancer is the second leading cause of cancer death, after lung cancer, in most developed countries. Our high intake of animal fats, trans-fats, and cholesterol are strongly linked to the development of this cancer.
Studies like this one are now explaining the mechanisms through which these fats, as well as the ingestion of cholesterol itself, alter cell behaviour in ways that convert normal, healthy cells into colon cancer cells. The take-home message remains to consume a diet that is low in animal fat, trans-fats, deep fried foods, and in cholesterol.
I have included a link to the research study in the text below
Bo Wang, Xin Rong, Elisa N.D. Palladino, Jiafang Wang, Alan M. Fogelman, Martín G. Martín, Waddah A. Alrefai, David A. Ford, Peter Tontonoz. Phospholipid Remodeling and Cholesterol Availability Regulate Intestinal Stemness and Tumorigenesis. Cell Stem Cell, 2018
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