Doctors have provided another justification for cutting out fatty foods - they will increase your risk of colon cancer.
Fatty foods have long been linked to poor health outcomes and potentially deadly conditions such as diabetes and heart disease.
According to experts at the U.S. Centers for Disease Control and Prevention (CDC), eating food high in saturated fats such as red meat strongly influence the risk of colorectal cancer, and scientists now believe they have discovered why.
"There's epidemiological evidence for a strong link between obesity and increased tumour risk," said Arizona State University School of Life Sciences assistant professor Miyeko Mana. "And in the intestine, the stem cells are the likely cell of origin for cancer. So, what is that connection? Well, diet is something that feeds into that cycle of obesity and colorectal cancer."
Mana's team have completed a new study of mice that details the link in greater detail than ever before and how broken-down foods making their way through the gut interact with intestinal stem cells (ISC) that lie along the inside surfaces of the gut - whose response to increased levels of fat in our diets may cause cancer.
From their data, Mana and her team found they could trace the development of cancer, from diet all the way to tumour formation.
First, fats are broken down to free fatty acids. The free fatty acids then stimulate sensors and turn on genes that can break down those acids. Surplus free fatty acids are transported to the mitochondria, which can burn them up by oxidation to make more energy to feed the stem cells, which multiply, grow and regenerate gut tissue. But when the ISC numbers are expanded, there is a greater likelihood of mutations that lead to colon cancer due to the number of cells present.
"The idea is that this larger pool of cells remain in the intestine and accumulate mutations, and that means they can be a source of mutated cells leading to transformation and tumour initiation," said Mana. "We do think that is a likely possibility when there are conditions that expand your stem cell pool."
The new research, which Mana hopes to expand to humans, provides hope that one day doctors will be able to greatly reduce the risk of colorectal cancer by understanding exactly how it develops over time.