Study Links Eating Yogurt to Changes in Brain Function

Patient Expert

You've probably heard that old adage, "You are what you eat." But it may go even further than that -- what you eat may actually affect your brain's functioning. That news should make you stop and really think about what you're putting on your plate (and into your mouth) if you're someone (like me) who has a family history of dementia and wants to do everything possible to avoid this condition.

A new study out of the University of California, Los Angeles found that changes in gut bacteria that are caused by diet also can result in changes in brain function.   This study involved 36 women who were between the ages of 18 and 55. The researchers divided the women into three groups. One group was asked to eat specific yogurt that contained a mix of several probiotics, which are bacteria that are believed to have a positive effect on the intestines. This group was asked to eat this type of yogurt two times daily over a four-week period. The second group was asked to eat a dairy product that was similar to yogurt but that did not contain probiotics. The third group did not eat yogurt or the dairy product.

The researchers took functional magnetic resonance imaging (fMRI) scans of the women's brains at the start of the study and then again after the four-week period. The scans were used to see the brain during a state of rest. MRIS also were taken during an emotion-recognition task in which the women were shown a series of pictures that had people with angry or frightened facial expressions and asked to match the photos to other faces with similar emotions. This particular assessment was designed to measure the engagement of the affective and cognitive brain regions in response to a visual stimulus.

Their analysis found that the group that ate yogurt had a decrease in activity in the insula (which processes and integrates internal body sensations) and the somatosensory cortex during the emotional reactivity task. These women also had a decrease in the engagement of a widespread network in the brain that includes areas related to emotion, cognition and senses. In comparison, the women in the other two groups had stable or increased activity in this network.

Furthermore, the women who consumed probiotics had greater connectivity between a key brainstem region and the cognition-associated areas of the prefrontal cortex during the resting brain scan.   The group that didn't eat any dairy product had greater connectivity between the brainstem region and the emotion- and sensation-related regions, while the group that ate the non-probiotic product had results in between these two groups.

"Many of us have a container of yogurt in our refrigerator that we may eat for enjoyment, for calcium or because we think it might help our health in other ways," said Dr. Kristen Tillisch, an associate professor of medicine at UCLA's David Geffen School of Medicine and lead author of the study. "Our findings indicate that some of the contents of yogurt may actually change the way our brain responds to the environment. When we consider the implications of this work, the old sayings 'you are what you eat' and 'gut feelings' take on new meaning."

The researchers believe that this research will lead to the expansion of studies designed to find new strategies to prevent or treat digestive, mental and neurological disorders through dietary changes. "There are studies showing that what we eat can alter the composition and products of the gut flora in particular, that people with high-vegetable, fiber-based diets have a different composition of their microbiota, or gut environment, than people who eat the more typical Western diet that is high in fat and carbohydrates," said Dr. Emeran Mayer, a professor of medicine, physiology and psychiatry at the David Geffen School of Medicine at UCLA and the study's senior author. "Now we know that this has an effect not only on the metabolism but also affects brain function."

Primary Source for This Sharepost:

Champeau, R. (2013). Changing gut bacteria through diet affects brain function, UCLA study shows. UCLA Health.