Colorectal cancer rates in the Acadiana region are among the nation’s highest, a health issue possibly linked to the region’s Cajun heritage, according to a study by the LSU Health New Orleans School of Public Health.

The possible link was found when researchers examined cancer data in parishes with the largest population of French speakers from 2005 to 2009. The study found higher colorectal cancer rates for those parishes than state and national rates.

“Obviously, we’d need to do further studies to try and figure out if it’s a hereditary effect or if there’s some kind of environment risk factor or if it’s some kind of combination of both,” said Dr. Jordan Karlitz, gastroenterologist at the Tulane University School of Medicine and adjunct faculty at the LSU Health Center.

“I think the important thing is that we identified a high-risk population, so at least we can go and study that population in more detail in hope to prevent cancer.”

The study, which began in 2013, looked at 18 parishes in southwestern Louisiana with large French-speaking populations and discerned that the risk for colon cancer was higher in the region for white people and particularly white males.

Between 2005 and 2009, the study says, there were 3,288 colon cancer cases identified among white males in the 18-parish region, which translates into 66 cases per 100,000 people.

The state’s rate for white males is 61 cases per 100,000 people. And for the nation, the rate for white males is 53.1 per 100,000 people.

The study found even higher colon cancer rates among white males in a subgroup of nine parishes with 10 percent or more French speakers than the other parishes studied. In those parishes, the rate of colon cancer incidents is 72.6 per 100,000 people. That statistic is 13 percent higher than for Louisiana as a whole and 23 percent higher than the rate for the United States.

The nine more at-risk parishes are Acadia, Assumption, Avoyelles, Evangeline, Jefferson Davis, Lafourche, St. Landry, St. Martin and Vermilion.

“In this population, we identified higher rates of colon cancer in the parishes where more French is spoken,” Karlitz said. “What we saw is that when you look at the more French-speaking parishes and you look at what the white population in that region, the rates of colon cancer is higher.”

The researchers chose to study the Acadiana region because of its “founder” population, or a population that breaks off from a main population, as the Cajuns who immigrated from Canada and France to Louisiana did in the 1700s.

“When you have a founder population like that, certain hereditary conditions can be seen in the population,” Karlitz said. “In the Cajun population, there are certain genetic diseases that are increased, such as Tay -Sachs.”

Tay-Sachs is an inherited disorder that destroys nerve cells in the brain and spinal cord. It’s rare in the general population but more common among Cajuns in Louisiana, Old Amish communities in Pennsylvania and families of eastern European Jewish descent, according to websites about the disease.

As for the possibility of Cajun cuisine being the main cause of the high risk of colorectal cancer rates in Acadiana, Karlitz maintained that more research would be needed to clear up conflicting studies on cancer and diet.

“Some of the dietary factors are hard to pin down,” he said. “Some studies suggest that red meat may be a dietary risk factor for colon cancer, but others don’t. Fruits and vegetables can protect, and in the Cajun diet, there are a lot of those and it’s definitely not clear.”

Future research could yield information on risk factors specific to the Acadiana region and beyond, Karlitz said.

The researchers were able to discern this information without having to collect their own information thanks to the state-mandated Louisiana Tumor Registry, which tracks cancer throughout the state and is readily available for scientists and analysts to use.

“This is very important to research,” Dr. Xiao-Cheng Wu, director of the Tumor Registry, located on the campus of the LSU Health Center in New Orleans. “This is exactly what our data should be used for. We need to let people know how important the Louisiana Tumor Registry is for cancer surveillance and prevention.”

The study used data from LSU Health New Orleans School of Public Health’s Louisiana Tumor Registry. The paper is published online in Clinical and Translational Gastroenterology, a Nature journal, at http://www.