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New research in mice finds links between a Western diet and cognitive decline. Catherine Falls Commercial/Getty Images
  • Researchers examine the role of a Western diet in cognitive decline and neurodegenerative issues in mice.
  • Previous research has shown a connection between poor diet and obesity and Alzheimer’s disease.
  • The new research in rodents may point to a mechanism behind this, which scientists could use to develop potential therapies for treating neurodegenerative disorders.

Over the past few years, studies on a typical Western diet have linked it to adverse reactions in the body, including prostate cancer, sepsis, and chronic gut infections.

A new study suggests that a Western diet may have a negative effect on the brain, leading to cognitive decline and neurodegenerative issues. The researchers believe their findings may offer potential therapies for the treatment of neurodegenerative disorders, such as Alzheimer’s disease.

The study appears in the journal iScience.

Neurodegenerative disorders include a variety of conditions resulting from loss of structure and function of the central or peripheral nervous system. The two most common neurodegenerative disorders are Alzheimer’s disease and Parkinson’s disease.

According to the Alzheimer’s Association (AA), more than 6 million adults in the United States have the condition, and the Parkinson’s Foundation states that about 1 million people in the U.S. have Parkinson’s disease.

Previous research shows that the impact of obesity and a poor diet can increase a person’s risk of developing a neurodegenerative condition, such as Alzheimer’s disease.

Another study earlier this year found that preventing obesity earlier in life through a healthier diet could delay or prevent Alzheimer’s disease.

A typical Western diet, which health experts also refer to as the Standard American Diet, usually includes greater amounts of food with higher calorie and fat percentages and lower nutritional value.

In a previous study, researchers from the Marshall University Joan C. Edwards School of Medicine (Edwards) in Huntington, WV, pinpointed a peptide called NaKtide as a way to block signals from the cellular sodium-potassium pump called Na,K-ATPase. By blocking the signal, the study authors lowered obesity growth in mice fed a high fat diet.

The present research suggests that a Western diet creates cognitive decline and neurodegeneration through increased Na,K-ATPase signaling in adipocytes, or fat cells.

When the researchers hindered the Na,K-ATPase signal through the use of NaKtide in those fat cells, they found it halted the adverse effects the Western diet had on the brain, especially the hippocampus, which plays a vital role in learning and long-term memory.

In the study, the researchers used a gene-altered mouse model. They fed the mice either a normal diet or a Western type diet for 12 weeks. They also gave the mice the antibiotic doxycycline to activate NaKtide in the fat cells.

At the conclusion of the study, the researchers observed that the mice eating the Western diet increased their body weight significantly compared with the mice on a normal diet. Additionally, the first group of mice showed noteworthy insulin resistance, low energy, and lowered oxygen levels.

Moreover, a Western diet increases the type of cytokine molecules that promote inflammation. The body requires both anti-inflammatory and pro-inflammatory cytokines to regulate the response of the other. Having too many inflammatory cytokines can cause certain conditions, including neurodegenerative diseases.

The study authors also found that the mice eating the Western diet showed signs of behavioral changes and changes in gene expression and signaling in line with those typical of people with Alzheimer’s and Parkinson’s diseases.

For the authors of the study, the next step is carrying out further research to try to replicate the present findings in humans. The research also shows the possibility of a therapy targeting turning off Na,K-ATPase signaling in fat cells.

According to senior study author Dr. Joseph Shapiro, M.D., vice president and dean at Edwards, while it is too early to talk about new medications that might target the adipocyte redox state, “Dietary modulation to avoid exacerbation of oxidative stress in adipocytes might be worth examining in clinical neurodegeneration.”

Medical News Today also spoke with Dr. Percy Griffin, Ph.D., director of Scientific Engagement for the AA, on what implications this research may have on suggested dietary changes for someone with Alzheimer’s disease or with heightened risk factors. He said:

“This research offers a novel avenue to attenuate the effects of the Western diet by blocking Na,K-ATPase signaling in fat cells. Although this work is interesting, the connection to neurodegeneration is preliminary. An important next step for this research would be to provide more evidence of neuronal protection and explore a mechanism for this effect.”

“Previous work has explored the effect of a high fat diet on inflammation in the brain and an increased risk [of] Alzheimer’s disease and other dementias. On the other hand, there’s a lot of work showing that eating a diet high in vegetables, fruits, and healthy fats — that is, the Mediterranean diet — may decrease one’s risk [of] cognitive decline. The [AA] is currently conducting a clinical trial called U.S. POINTER that aims to evaluate whether lifestyle interventions — including eating a healthy diet, getting regular exercise, and staying cognitively engaged — can reduce risk of cognitive decline.”

What potential implications this research might have on a typical Western diet? “Rodents differ from humans in many, many ways, and it is quite possible that components of what we call a Western diet, such as high fat, may be less problematic in people than in rodents,” Dr. Shapiro told MNT.

“However, we do think that simple sugars, especially fructose, may be problematic for people as well as rodents, based on extensive study by other researchers.”