Certain Fatty Acids Responsible for Worsening Crohn's Disease

Palmitic acid found in olive oil, butter, cheese, milk, and meat may worsen inflammation.

A recent study evaluated the role of omega-6 and omega-7 fatty acids in relation to Crohn’s disease, and found that depending on which is at play, it could worsen or improve the disease’s condition.

Crohn’s disease is an inflammatory condition of the digestive tract that causes abdominal pain, diarrhea, fever, and weight loss. The causes of the disease are unknown, but it is thought to stem from an interplay between environmental and genetic factors.

There is no cure for the disease, but it can be managed through lifestyle alterations in patients, such as dietary changes and taking anti-inflammatory drugs.

“Dietary therapies for Crohn’s disease should be examined more systematically, and this study provides a good first step,” said Dennis Ko, an assistant professor of molecular genetics and microbiology in the Duke School of Medicine.

Research has suggested that high-fat diets may be linked to Crohn’s disease, but never have the 2 been joined through shared genetics. Genetic variations occur more often in people with Crohn’s disease, including subtle changes to the DNA such as a single-letter change.

Separate studies show that specific genetic variations are linked to higher levels of some fatty acids in the bloodstream. In this particular study, researchers identified overlaps between palmitoleic acid, a type of omega-7 fatty acid, and Crohn’s with a software tool called CPAG.

The software allows researchers to evaluate the results of more than 1400 genome-wide association studies that have been published on the topic thus far.

“The basis of the approach is simply to ask, ‘Is the [genetic] overlap between the two diseases or traits more than you’d expect just by chance?’” Ko said.

In the past, this question went unanswered. CPAG will continue to grow as the inclusion of additional data becomes available and other researchers can use the software to analyze their own genetic findings in light of all published studies.

The software, however, does not predict the relationship between 1 trait or disease and another.

Researchers tested zebrafish models to see whether fatty acid levels in the bloodstream was a cause or a consequence of the disease. To their surprise, omega-7 was not responsible for worsening the inflammation. Rather, it was its saturated counterpart, palmitic acid, found in olive oil, butter, cheese, milk, and meat.

Another surprise for scientists came in the fact that omega-6 fatty acid lessened inflammation in the zebrafish, which is found in vegetable oils. Omega-6 had been shown in a previous study to be lower than normal in the blood Crohn’s disease patients.

Ko warns that patients should not jump to conclusions and change their diets in an attempt to lessen the effects of the disease. More research needs to be done to confirm or disprove the findings of this study.

“If we can deepen our understanding of lipid imbalance in Crohn’s disease and the consequences of having too much or too little of any one lipid in particular, then we might eventually be able to develop new strategies for managing Crohn’s disease and other inflammatory disorders,” said John Rawls, co-author of the study and associate professor of molecular genetics and microbiology in the Duke School of Medicine.