Eating vegetables and fruits can release a molecule in the body that can douse the inflammation in colon before triggering cancer development, according to a new study.
The study by Texas AgriLife Research scientist Dr. Nancy Turner revealed that the molecule, called quercetin, gets into the body through onions, peppers, tomatoes and most other common produce but also in "fun things like wine,"
Turner said: "Just about any plant-based food in the human diet has some level of quercetin."
While earlier studies showed quercetin was effective in reducing the rate of colon cancer in laboratory tests, the currents study has shown how quercetin could help other inflammatory bowel diseases such as Crohn's and celiac disease.
"The nice thing is that albeit high relative to what you see in the American diet, the level used in this study is actually similar to what can be achieved in diets around the world such as in, say, the Mediterranean-style diets. So it's not an unachievable goal for us good ol' Americans if we do the right thing with our food consumption," said Turner.
For this study, the researchers examined the response of quercetin-supplement diets in lab rats, some in the early stages of colon cancer formation and others without cancer.
"Early lesions in a colon are some of the first true changes in the colon that can be observed visually. This in not just something you see in our animal model. You see it in human patients as well," she said.
Called "aberrant crypts," they are thought to be a marker or predictor of tumour formation. She noted that quercetin is known to reduce the number of these crypts.
"We were able to decrease the number of cells that were proliferating in the colon. And we were able to increase the number of cells that were undergoing apoptosis. So the net effect of that is, we were able to maintain almost a normal number of cells," she said.
Then the researchers decided to examine relatively new findings - that inflammation is one of the biggest contributors of the development of colon cancer.
They targeted two enzymes - known to researchers as Cox-1 and Cox-2. The first is a routine protein that the body expresses all the time, she said. But the second Cox has implications in a lot of diseases.
"Cox-2 is an inducible protein that is expressed in the body when there is some kind of external stimulous to a cell. We think of high levels of Cox-2 as being a bad thing," said Turner.
One of those bad things is colon cancer. Not only is Cox-2 present in that disease, but recent research showed that before Cox-2 levels rose in colon cancer, the Cox-1 levels first became elevated. Cox-1, therefore, has some sort of control over whether Cox-2 gets expressed, she explained.
"We did see that both groups - both the control groups and the carcinogen-injected groups that were consuming quercetin in their diets - had lower levels of both Cox-1 and Cox-2. So that would tend to suggest that there may be opportunity for quercetin to suppress tumour development," said Turner.
She said that additional research is needed on this portion of the work to better understand the connections. But she advised people to go ahead and eat plenty of fruits and vegetables.
She noted that in addition to colon cancer, quercetin has shown positive impacts in warding off other chronic ailments such as cardiovascular disease.
The study is published in the Journal of Nutrition.