A growing body of evidence indicates that the trillions of bacteria that live in the digestive tract – might play a role in altering cancer risk. Now, a study suggests that how those bacteria are organized and where they are located in the gut might influence the risk of certain colon cancers.
The study, published in The Proceedings of the National Academies of Science, focused on biofilms – communities of bacteria that help bacteria communicate with each other and grow more efficiently.
When bacteria organize into biofilms, they can breach the protective inner layer in the gut and invade the local tissue, promoting inflammation and possibly cancer.
We have an interesting relationship with the bacteria in our gut. Although many of the microbes provide beneficial services, bacteria – both “good” and “bad” – can cause us harm, so we keep them all at arm’s length, so to speak. Normal, healthy tissue in the colon is coated with a two-layered covering of mucus –a mesh-like outer layer and a gel-like inner layer. Whereas the outer layer creates a moist, cozy environment for bacteria, the inner layer is less hospitable: it provides the last line of defense against their invasion.
A paper published recently in the journal Science has generated an enormous amount of media coverage. The paper’s matter-of-fact title, “Variation in Cancer Incidence Among Tissues Can Be Explained By the Number of Stem Cell Divisions,” doesn’t sound like something that would set the internet buzzing, but it sure did.
That’s because of how the paper was promoted and covered: “MOST CANCERS DUE TO BAD LUCK, NOT PREVENTABLE, STUDY FINDS” screamed one headline. But there’s a sharp disconnect between this paper’s findings and the hype surrounding it.
Here at AICR, we fund and analyze the research showing that a healthy weight, a healthy diet and regular physical activity could prevent hundreds of thousands of U.S. cancers every year. We’re concerned that the oversimplified coverage this study received will reinforce the widespread conviction that cancer “just happens” and cause Americans to throw up their hands and ignore the empowering, evidence-based message that everyday choices play an important protective role in risk for many of the most common cancers.
When looking at this paper, ask yourself three basic questions. Continue reading
There’s strong research now showing that being active can reduce your risk of colorectal cancer, but how physical activity affects survivors of this cancer is not as clear. Now comes a study suggesting that being active — both before and after diagnosis —can lengthen survival for colorectal cancer survivors.
Not watching a lot of television — a common measure for sedentary living — was also found to improve survival. Survivors who were watching fewer than two hours a day of TV before diagnosis had a reduced risk of mortality compared to those watching five or more hours of TV a day.
The study was published in the Journal of Clinical Oncology last week.
For pre-diagnosis, study authors used data from approximately 3,800 survivors who were part of the large NIH-AARP Diet and Health Study study. In the mid 1990s, the participants were 50 to 71 years old. They answered questionnaires about how much TV they watched, their activity and other lifestyle habits. Those who had developed colorectal cancer were identified in 2006. Continue reading