Exercise That May Slow Alzheimer's

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The benefits of physical exercise include both reducing the risk of dementia as well as slowing the progression of dementia once it's present. But, is there a certain type of exercise that is the most effective?

There are multiple studies that have looked at this question. Here are summaries of four different studies that provide interesting insights about the role of different kinds of exercise and how they affects our brains.

In the first study, older adults between the ages of 65 and 93, all of whom had a diagnosis of mild cognitive impairment, were split between a physical exercise group and a control group which received three educational classes on health over the course of 12 months. The exercise group's curriculum consisted of aerobic exercise, muscle strength training, and postural balance retraining.

The results in this study demonstrated a clear improvement in both memory and in overall cognitive functioning for participants in the exercise group. They also showed that brain volume was maintained for those in the exercise group. Brain atrophy has been strongly correlated with cognitive decline.

Although this study doesn't isolate one type of exercise or compare different types of exercise, it does add to the evidence that exercise which includes aerobic activity, muscle strength training and postural balance training can impact brain functioning.

In the second study, 120 sedentary older adults without dementia were randomly assigned to either an aerobic walking group or a stretching/toning group. After one year, those in the walking group showed a 2% increase in the size of their hippocampus as compared to the stretching group. The hippocampus is a part of the brain that controls memories, and it's one of the earlier places that shrinks and deteriorates in Alzheimer's.

In this study, the volume increase in the hippocampus was also directly related to an improvement in the participants' memory functioning.

This study demonstrates that the brain of older adults can continue to grow and improve, and that walking regularly may be one way to encourage this.

In the third study, 86 women with mild cognitive impairment (a condition where the risk for developing Alzheimer's is high) were randomly assigned to one of three groups:

  • Resistance/Weight Training
  • Aerobic/Walking
  • Balance & Tone

The results? The weight training group showed a significant improvement in selective attention (as measured by the Stroop Test) as well as associate memory, The participants in this group also demonstrated functional improvements in brain plasticity.

The walking group did show an increase in the scores on one different memory task called the Rey Auditory Visual Learning Test, but did not demonstrate any other improvements or any physical changes in the brain. The balance and toning group demonstrated no cognitive improvements.

The researchers concluded that weight-training for those already diagnosed with mild cognitive impairment was an effective way not just to stave off Alzheimer's, but even to improve the cognitive function and physical health of the brain.

A fourth study compared how the initial level of cognitive functioning affected the results after participants were assigned to either a weight training group or a balance/toning group. According to the Alzheimer's Association International Conference, the results demonstrated that:

  • The most improvement came from those who were in the resistance training group and had higher cognitive functioning at the beginning of the study.
  • For participants with lower cognitive functioning at the beginning of the study, the effects of weight training and balance/tone exercises were about equal.
  • Overall, participants in the balance/tone exercise group were the least likely to demonstrate improvement and the most likely to decline.

What are they saying, in summary? Prevention appears most effective while the brain is healthy, and early detection and exercise (specifically resistance/weight training) is key to maintaining cognitive functioning.

Sources:

Alzheimer's Association International Conference (AAIC) 2012. July 15, 2012. Abstracts F1-03-01, FI-03-02, P1-109, and P1-121.

Archives of Internal Medicine. 2012;172(8):666-668. Preventing dementia: Trajectory of cognitive decline can be altered in seniors at risk for dementia. http://www.sciencedaily.com/releases/2012/04/120423162403.htm

JAMA Internal Medicine. April 23, 2012, Vol 172, No. 8. Resistance Training Promotes Cognitive and Functional Brain Plasticity in Seniors With Probable Mild Cognitive Impairment. http://archinte.jamanetwork.com/article.aspx?articleid=1135414#Results

PLOS One. April 09, 2013. A Randomized Controlled Trial of Multicomponent Exercise in Older Adults with Mild Cognitive Impairment. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0061483

Proceedings of the National Academy of Sciences of the United States of America (PNAS).  February 15, 2011.vol. 108, no. 7. Exercise training increases size of hippocampus and improves memory. http://www.pnas.org/content/108/7/3017.full

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