Western Diet Linked To Neurodegenerative Diseases

What is the Western Diet? 

The Western Pattern Diet is a modern-day style diet that mostly contains high amounts of processed foods, red meat, high-fat dairy products, high-sugar foods, and pre-packaged foods, that increase the risk of chronic illness.

This diet is “rich in red meat, dairy products, processed and artificially sweetened foods, and salt, with minimal intake of fruits, vegetables, fish, legumes, and whole grains.

In 2006 the typical American diet was about 2,200 calories per day, with 50% of calories from carbohydrates, 15% protein, and 35% fat. These macronutrient intakes fall within the Acceptable Macronutrient Distribution Ranges (AMDR) for adults identified by the Food and Nutrition Board of the United States Institute of Medicine as “associated with reduced risk of chronic diseases while providing adequate intakes of essential nutrients,” which are 45–65% carbohydrate, 10–35% protein, and 20–35% fat as a percentage of total energy. 

However, the nutritional quality of the specific foods comprising those macronutrients is often poor, as with the “Western” pattern.

A review of eating habits in the United States in 2004 found that about 75% of restaurant meals were from fast-food restaurants. Nearly half of the meals ordered from a menu were hamburgers, French fries, or poultry — and about one-third of orders included a carbonated beverage drink.

Neurodegenerative disease is an umbrella term describing a group of conditions characterized by progressive nervous system dysfunction. These include Alzheimer’s disease (AD), Parkinson’s disease (PD), and mild cognitive impairment (MCI), a state of impaired cognitive function that is early and abnormal, but symptoms are not as severe as dementia.

Clinical Studies

A study by Morris et al showed that high saturated fat intake is associated with increased risk of Alzheimer’s disease over a 4-6 year period in adults greater than 65 years of age. 

Diet has also been suggested as a factor contributing to the development of Parkinson’s disease. Population-based case-control studies have demonstrated that, compared to healthy controls, individuals with Parkinson’s have a higher intake of total fat and saturated fat 5 years preceding diagnosis and higher intake of animals fats 1-year preceding diagnosis. 

The Western diet can lead to changes in brain regions associated with energy regulation and the affective appraisal of food according to different studies. It is now widely agreed that there has been a rise in obesity levels in Western societies over the past 30 years, with recent estimates suggesting greater than one-third of the United States population are obese. Both overweight and obesity are major risk factors for non-communicable diseases such as type 2 diabetes, cardiovascular diseases, and cancer. 

These diets are also starting to be viewed as contributing factors to the onset of Attention-deficit and hyperactivity disorder and other neurodegenerative conditions, and these neural dysfunction result in impaired social, educational, and occupational function. 

New Study Findings

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 from Komal Sodhi and colleagues, published in the journal iScience 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 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.

They used a gene-altered mouse model and fed the mice either a normal diet or a Western-type diet for 12 weeks. They observed that the mice eating the Western diet increased their body weight significantly compared with the mice on a normal diet. 

They also saw that 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 authors consider that the next step is carrying out further research to try to replicate their findings in humans. It also shows the possibility of a therapy targeting turning off Na.K-ATPase signaling in fat cells. 

Sources: 

Corrie Pelc (2021, Oct 27). Western diet linked to cognitive decline and neurodegeneration in mouse study. Medical News Today. Retrieved from:
https://www.medicalnewstoday.com/articles/western-diet-linked-to-cognitive-decline-and-neurodegeneration-in-mouse-study

Last, Allen R.; Wilson, Stephen A. (2006). “Low-Carbohydrate Diets”. American Family Physician. 73 (11): 1942–8. PMID 16770923

Food and Nutrition Board. Institute of Medicine (2005). Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington, DC: The National Academies Press. pp. 14–15. doi:10.17226/10490.  

Heather Francis, et al. The longer-term impacts of Western diet on human cognition and the brain. Appetite. 2013. Volume 63, 2013, Pages 119-128, ISSN 0195-6663. https://doi.org/10.1016/j.appet.2012.12.018.

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https://www.medicalnewstoday.com/articles/320616