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Possible Factors that can Reduce Effects of Decline and Dementia in the Old-Age (Part 2)



In part 1 of this article series, we examined two studies on how cognitive activity is affecting cognitive performance in later years. In this second article, we will look at how physical activity and cardiovascular risk factors may influence the outbreak of Alzheimer’s Disease.

Physical Activity

Study 1 (Low and High Intensity Exercise)

In the past, studies on the influence of physical activity on the brain have relied on numerous volunteers submitting their own reports as to how much they exercise over their lifetime, or a certain period of time. Rush University Medical Center in Chicago offered a different approach to such studies, in a population of more than 700 senior people with an average age of 82 whom were all dementia-free prior to the study. Each volunteer was fitted with an actigraph, a device that is worn on the wrist for up to 10 days, that records all physical activity, including exercises like running, gardening, and even fidgeting.

The volunteers’ cognitive health was tracked over the next 4 years, and it was found that those with the highest levels of daily activity, according to the actigraph, had the slowest rates of cognitive decline, and also had about half the risk of contracting Alzheimer’s, when compared to the other less active participants.

Senior exercise

Study 2 (Exercise and Diet)

In another study at the University of Washington in Seattle, it was found that physical activity, along with diet, influenced changes in beta-amyloid 42 levels in cerebrospinal fluid, changes very similar to those of Alzheimer’s. This particular study included a total of 41 participants of an average of 68, with normal or mild cognitive impairment (MCI). Based on surveys of their typical exercise levels and frequencies, the volunteers were categorized in varying levels of intensity of physical activity groups. (High-intensity activities included aerobic classes, biking, swimming, etc) (Low-intensity activities included walking the dog, stretching, gardening, etc) For 4 weeks, the participants followed either a healthy diet (low in saturated fats and refined sugars), or an unhealthy diet (high in saturated fat and sugar), while maintaining their regular lifestyle and levels of exercise.

At the beginning and end of the study, the volunteers were measured in their levels of several CSF Alzheimer’s biomarkers. Beta-amyloid 42, one of these markers, was impacted by diet. This biomarker decreased (moved towards Alzheimer’s) in participants whom ate the unhealthy diet, and increased (moved towards normal levels) in those who ate the healthy diet. As well, those whom regularly engaged themselves in high-intensity exercises, alongside the healthy diet showed even greater benefits on beta-amyloid 42 levels. Even those who were part of the unhealthy diet, but still engaged in high-intensity exercise, showed less negative impacts from the unhealthy diet. All in all, the results from this study suggest that the potential of a healthy diet is highest when combined with regular, high-intensity exercise.

Study 3 (Effects of exercise on the brain)

Numerous studies have shown that brain function is positively influenced by aerobic exercise in older adults, but it is unclear as to which mechanisms in the body perform this. A study made at the University of Iowa suggests that by exercising, an individual increases the levels of certain protein growth factors that give support to neuronal health. This particular study included 65 senior individuals with an average age of 99, whom were assigned to one of two programs: an aerobic walking program, or a control program of balance and flexibility exercises.

After the span of one year, those in the aerobic walking program displayed higher levels of functional connectivity on MRI scans in various brain networks that supposedly degenerate with age, as compared to the balance group. In the aerobic group, this improved functional connectivity was associated with an increase in the blood levels of three growth factors: brain-derived neurotrophic factor, insulin-like growth factor type 1, and vascular endothelial growth factor. All three of these factors are known to promote neutral growth, functionality, and plasticity.

Cardiovascular Risk Factors

Another group of factors that may increase the risk of Alzheimer’s disease are cardiovascular diseases, such as high blood pressure. A study at Banner Alzheimer’s Institute in Phoenix, utilized positron emission tomography imaging to show that high blood pressure levels led to increased brain beta-amyloid levels in cognitively normal adults. The participants in this study included 32 adults, aged 47 to 68, all with normal cognitive levels. Brain scans showed lower brain glucose metabolism (a symptom leading to Alzheimer’s) in the adults with higher blood pressure.


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