Only a few days of eating a high diet in saturated fat could be enough to cause memory problems and related cerebral inflammation in older adults, suggests a new study in rats.
The researchers fed separate groups of young and old rats, the high diet in fat for three days or for three months to compare how fast the changes in the brain against the rest of the body occur when they eat an unhealthy diet.
As expected based on the previous research of diabetes and obesity, eating fatty foods for three months led to metabolic problems, intestinal inflammation and dramatic changes in intestinal bacteria in all rats compared to those that ate normal chow, while only three days of high fat did not cause important metabolic or intestinal changes.
However, when it came to changes in the brain, the researchers found that only the oldest rats, if they were in the high fat diet for three months or only three days, had a bad performance in the memory tests and showed negative inflammatory changes in the brain.
The results dissipate the idea that the inflammation related to the diet in the brain that ages is driven by obesity, said Senior study author Ruth Barrientos, a researcher at the Institute for Behavioral Medicine Research at Ohio State University. Most research on the effects of fatty and processed foods have focused on obesity, however, the impact of unhealthy food, independent of obesity, remains largely unexplored.
“The unhealthy diets and obesity are linked, but they are not inseparable. We are really looking for the effects of the diet directly on the brain. And we show that within three days, long before obesity is established, tremendous neuroinflammatory changes are occurring at the University of Medicine of the State of Ohio.
“Changes in the body in all animals are occurring more slowly and are not really necessary to cause memory disability and brain changes. We would never have known that brain inflammation is the main cause of alterations of memory induced by the high diet in fat without comparing the two timelines.”
The research was recently published in the magazine Immunity and aging.
Years of research in the Barrientos laboratory have suggested that aging causes a long -term “barley” of the inflammatory brain profile along with a loss of reserve of brain cells to recover, and that an unhealthy diet can make things worse for the brain in older adults.
Fat constitutes 60% of the calories in the high fat diet used in the study, which could be equated with a variety of fast food options: for example, nutritional data shows that fat represents approximately 60% of the calories in a double book by McDonald’s Double Smoky BLT with cheese or a burger King Double Whopper with cheese.
After the animals were in high -fat diets for three or three months, the researchers performed tests that evaluated two types of common memory problems in older people with dementia that are based on separate regions of the brain: contextual memory mediated by the hippocampus (the primary memory center of the brain) and the memory of caddas failures that originates in the tonsil (the fear and the center of the dog brain).
Compared to control animals that eat chow and young rats in the high fat diet, aged rats showed that behaviors that indicate that both types of memory were affected after only three days of fatty foods, and the behaviors persisted as they continued with the high diet in fat for three months.
The researchers also saw changes in the levels of a range of protein called cytokines in aged rats after three days of fatty foods, which indicated a deregulated inflammatory response. Three months after being in the high diet in fat, some of the cytokine levels had changed but remained deregulated, and cognitive problems persisted in behavioral tests.
“A deviation of basal inflammatory markers is a negative response and it has been shown that it harms learning and memory functions,” said Barrientos.
Compared to the rats that eat normal chow, young and old animals obtained more weight and showed signs of metabolic dysfunction (bad insulin control and blood sugar, inflammatory proteins in the fat tissue (adipose) and alterations of the intestinal microbiome, after three months with the high diet in fat. The memory and behavior of young rats and brain tissue Fatty foods.
“These diets lead to changes related to obesity in young and old animals, however, young animals seem more resistant to the effects of the high diet in memory in memory. We believe that it is probably due to their ability to activate compensatory anti -inflammatory responses, which lack elderly animals,” Barrientos said.
“In addition, with the inflammation of glucose, insulin and adipose, everything in young and old animals, there is no way to distinguish what is causing the deterioration of memory only in old animals if you only look at what is happening in the body. It is what is happening in the brain what is important for the response of memory.”
This work was supported by subsidies from the National Institute on Aging.
Co-authors include Michael Butler, Stephanie Muscat, Brigitte González Olmo, Sabrina Mackey-Alfonso, Nashali Massa, Bryan Alvarez, Jade Blackwell, Menaz Bettes and James De Demars of the state of Ohio; and Maria Elisa Caetano-Silva, Akriti Shrestha, Robert McCusker and Jacob Allen of the University of Illinois in Urbano-Champaign.