Dietary patterns are very important in determining certain detrimental and advantageous effects on the body. This study reveals the biomarkers or indicators of cognitive impairment specifically Alzheimer’s disease. Authors conducted diet interventions and studied the comparative effects of high-saturated fat/high-simple carbohydrate (HIGH) diet versus low-saturated fat/low-simple carbohydrate (LOW) diet on cerebrospinal fluid present in our nervous system. The main findings of this study are that a high saturated-fat and simple-carbohydrate diet generates some disease-related processes in the brain that increase the chances of getting Alzheimer’s disease. On the other hand, low saturated-fat and low simple-carbohydrate diet contain a defensive mechanism against Alzheimer’s disease.
Consumption of saturated fats and simple carbohydrates can lead to obesity, diabetes, and heart diseases, which are proven risk factors for brain aging. Previous diet intervention studies on animal models have shown that high-saturated fat or high-simple sugars diet can modulate one of the proteins in the body, causing errors in insulin signaling in the brain. There has not been any study that considered the effects of diet interventions on biomarkers for Alzheimer’s disease in cerebrospinal fluid in humans. This study can help to determine the effect of diet on Alzheimer’s disease and its possible treatment plans. “This important area of study might elucidate the early effects of diet on Alzheimer’s disease pathogenesis and implicate diet as a critical environmental factor in the Alzheimer’s disease causal pathway.”
* Forty-nine adults were studied, of whom 20 healthy individuals (average age 69.3) were taken as controls and 29 (average age 67.6) had amnestic mild cognitive impairment (aMCI), a disorder causing Alzheimer’s disease.
* The participants in both the groups received HIGH diet or LOW diet randomly.
* These participants were given cognitive testing, oral glucose tolerance testing, blood collection to measure glucose, insulin, and cholesterol levels, and lumbar puncture to take out cerebrospinal fluid. These procedures were performed before the diet intervention and in the fourth week after it.
* Some protein assays for Alzheimer’s disease biomarkers were also performed.
* HIGH diet results in raised insulin in the body and lowered insulin sensitivity, whereas LOW diet results in reduced insulin and high insulin sensitivity.
* HIGH diet raised the cholesterol concentration and LOW diet lowered these concentrations in both the groups. In MCI groups, changes were found to be two-fold.
* The concentration of a protein reflecting oxidative damage to central nervous system decreased in LOW diet and increased in HIGH diet.
* Delayed visual recall improved with LOW diet in both the groups.
The length of time for HIGH diet consumption was restricted because of safety issues. Longer exposure might have provided more insights into cognitive changes. Also, the sample size of this study was small. More samples can lead to a more thorough analysis. This study requires manipulation of the amount and type of carbohydrates and fats because the diet was designed in a way that promotes insulin resistance and type 2 diabetes. This manipulation may have produced different results.
This diet intervention on human model study gave us the overall picture of how Alzheimer’s disease biomarkers in central nervous system are affected by diet-induced metabolic changes. Diets low in saturated fats and simple sugars are related to improved biomarker profiles and delayed memory. These diets can improve brain health and provide protection from Alzheimer’s disease. This study can be explored further and extended for longer durations, which might help in identifying some therapeutic targets. The study of functional changes associated with dietary effects may open up important sites that can guide us in designing effective treatment options for Alzheimer’s disease.
For More Information:
Diet Intervention and Cerebrospinal Fluid: Indicators in Functioning of Brain Processes
Publication Journal: Archives of Neurology, February 2011
By Jennifer Bayer-Carter; Pattie Green, PhD