Everyone knows that overdosing on fat and sugar can add extra pounds and cause a variety of physical health problems. Researchers from Oregon State University say that the dietary indulgence can also go to your head.
In a study published in the journal Neuroscience and reported by Honor Whiteman in Medical News Today, the researchers say that mice consuming high-fat or high-sugar diets had gut bacteria changes that reduced cognitive functioning, sugar was the biggest problem and a gut microbe called Akkermansia muciniphila could prove effective in improving thinness and metabolic health among overweight or obese people (http://www.medicalnewstoday.com/articles/295785.php).
According to the study, high-fat and high-sugar diets are responsible for changes in gut bacteria associated with loss of "cognitive flexibility," the ability to adapt to changing situations. The high-sugar diet was also associated with poorer short- and long-term memory. As principal investigator Prof. Kathy Magnusson, of the College of Veterinary Medicine and the Linus Pauling Institute at Oregon State, explained, "Bacteria can release compounds that act as neurotransmitters, stimulate sensory nerves or the immune system and affect a wide range of biological functions. We're not sure just what messages are being sent, but we are tracking down the pathways and the effects."
The Oregon State researchers used 2-month-old male mice, which were fed either a high-fat diet (42% fat, 43% carbohydrate), a high-sugar diet (12% fat, 70% carbohydrate, mainly from sugars) or a normal diet. Before and after the dietary intervention, the researcher team analyzed the feces of the mice to determine the composition of their gut bacteria and assessed their short- and long-term memory and cognitive flexibility by means of water maze testing and novel object and location tasks. Prof. Magnusson explained cognitive flexibility as needing to find a different route home when the familiar road is closed. Both diets showed an increase in bacteria called Clostridiales and a reduction in bacteria known as Bacteroidales. These changes were associated with reduced cognitive flexibility.
An even more remarkable study at Oregon State found that three-fourths of elementary school children in a highly educated community in the Pacific Northwest had vitamin D levels that were either insufficient or deficient, and they also lacked an adequate intake of other important nutrients. The results of the study, reported last year in the Journal of Extension by scientists from the Linus Pauling Institute at Oregon State, show that nutritional deficiencies can be huge even in communities with a very knowledgeable population and easy access to high quality, affordable food. While other studies have found similar concerns in areas with low socioeconomic status, poor food availability and lower levels of education, it was unexpected in Corvallis, Oregon, a university town with many grocery stores, a free bus transit system and some of the highest educational levels in the nation (http://oregonstate.edu/ua/ncs/archives/2014/oct/educated-community-no-protection-against-poor-diet-children).