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Saturday, March 17, 2018

Aerobic Exercise Makes You Smarter

On several occasions, I have written about the anti-aging beneficial effects of exercise. New studies, confirm earlier findings of exercise benefit. Now, a new study shows that exercise reduces levels of the major inflammatory chemical, interleukin-6, and an associated enhancement of neural activity in the brain circuitry used to encode information and form memories.
In response to earlier studies by others showing that exercise improves mental function, a team from mostly German universities studied the effects of exercise on 32 subjects aged 52 to 71 years old. They were particularly interested in memory because prior studies by others made it clear that age usually impairs memories of names and faces, situations and events, which are categorized as episodic memory. Tests of recall of episodic memory show marked age decrements in many subjects, even if they are given reminder cues.
Other researchers had shown that exercise, particularly aerobic exercise, reduces decline of episodic memory. This group of researchers wanted to explore why this benefit occurs. They examined two possibilities for the benefit of exercise:

1. Reduction of inflammatory chemicals (interleukin-6), which is known to occur with aerobic exercise in younger people, and
2. Strengthened connection among neurons that encode and form episodic memories (in the hippocampus, thalamus, and medial prefrontal cortex).

In the experiment on day one, subjects completed a survey that revealed each person's level of physical activity over the past week and gave a blood sample for measuring the baseline level of interleukin-6. Each subject then took several standardized tests of episodic memory. Then each subject had their brains scanned with fMRI while they were asked to memorize a series of faces and their association with a profession (pilot, electrician, bus driver, etc.). After the scan, they were tested for recall. The purpose of the scan was to assess functional connectivity, that is, how strongly the activation correlated in the brain areas that participate in encoding and memory formation.
The exercise survey allowed subjects to be grouped on the basis of aerobic and non-aerobic exercise during the prior week. The aerobic group remembered more items on the episodic memory task. The aerobic group also revealed stronger functional connectivity among several areas in the memory network. Additionally, there was a correlation with levels of the inflammatory chemical: subjects showing strong functional connectivity had the lowest levels of interleukin-6.
Limitations of the study include a failure to distinguish the intensity of exercise. For example, one can jog three hours a week at high speed or rather leisurely. Also, actual fitness of each subject was not measured, just a log of their exercise activities during the prior week. Another factor is that only one inflammatory chemical was studied. Interleukin-6 is one of a large family of such chemicals known as cytokines, and there are other inflammatory chemicals as well. Moreover, the significance of interleukin was not evaluated. When brain is damaged (by stress, metabolic production of free radicals, or whatever), interleukin-6 is released as a defense mechanism.
Nonetheless, a strong correlation, consistent with prior studies, was demonstrated between aerobic exercise, inflammation, and mental function. The authors did not speculate on why these effects occurred. I will.
Two contributing factors are obvious. One obvious factor is that aerobic exercise improves cardiovascular function and likely improves blood flow through the brain. The other obvious factor is that aerobic exercise releases the "feel-good" endorphins. Endorphins alleviate stress. Stress, more specifically the cortisol released during stress, shrinks the synaptic connections between neurons, which of course can be expected to diminish functional connectivity and information processing efficiency. Stress increases the level of inflammatory chemicals like interleukin-6. The low level of interleukin-6 in the aerobic group indicates that these brains were somewhat protected from the ravages of stress and free radicals.
Bottom line: aerobic exercise is good for older people. In addition to the well-known cardiovascular benefits, aerobic exercise makes people more sharp mentally. How one gets the needed aerobic exercise probably doesn't matter, as long as the exercise is sufficiently intense and sustained. Jogging, bike riding, swimming, and fast-moving sports should all prove beneficial.

Readers of this column will be interested in "Memory Medic's" e-book, Improve Your Memory for a Healthy Brain. Memory Is the Canary in Your Brain's Coal Mine (available in all formats from The book, devoted exclusively to memory issues in seniors, includes review of many of the ideas in these columns over the last five years.


Thielen, Jan-Willem et al. (2016. Aerobic activity in the healthy elderly is associated with larger plasticity in memory related brain structures and lower system inflammation. Frontiers in Aging Neuroscience. 26 December. doi.: 10.3389/fnagi.2016.00319

Erta, M., Quintana, A., and Hidalgo, J. (2012) Interleukin-6, a Major Cytokine in the Central Nervous System. Int. J. Biol. Sci. 8(9):1254-1266. doi:10.7150/ijbs.4679. Available from

Monday, March 05, 2018

Lifestyle Effects on Working Memory Ability

On multiple occasions, readers of my learning and memory blog posts asked me what they could do to improve their working memory. This is an important and very practical question. Working memory affects all aspects of life success: personal, educational, and professional. I usually tell them to practice attentiveness and concentration. But I probably should tell them to adapt a healthier lifestyle.

For over a decade a variety of studies have implicated lifestyle in memory function. A rigorous new study confirms these results. An Israeli research team studied 823 participants, aged 22-37 years, using brain scans taken during a difficult memory task, post-scan memory tests, and numerous measures of health and lifestyle. The brain scans identified the brain areas that particularly engage in working memory tasks, most important of which were the dorsolateral prefrontal cortex, parietal cortex, and anterior cingulate cortex. These then served as a frame of reference to check for correlations with health and lifestyle.

The key finding was a strong correlation between activity in working-memory brain areas and health and lifestyle. With all behavior/health variables considered together, the highest positive correlation occurred, in order, with fluid intelligence, reading, spatial orientation, picture vocabulary, several memory tests, and attentiveness.  

They observed an opposite correlation for such specific life-style indicators as large body mass index and a variety of unwise lifestyles such as binge drinking, and regular smoking. Health variables that correlated negatively with working-memory brain areas included high body-mass index, high blood pressure, poor glucose regulation.

The healthy lifestyle variables also correlated with other cognitive functions, such as fluid intelligence, reading/language skills, visuospatial orientation, sustained attention, mental flexibility and emotional intelligence, and physical endurance. Thus, the working memory benefit from healthy lifestyles seems to reflect a general improvement of brain function that good health confers.
The principle confirmed here supports the underlying theme of my recent e-book for seniors, which explained how memory serves a function like a canary in the coal mine. Memory decline is a warning signal of a damaged brain. That book explains the healthy life styles that people should be using as they age in order to keep the brain healthy and prevent memory deterioration. Changing lifestyle after the damage has already occurred may be too late. The point is that young people with healthy lifestyles have better brain function, and those lifestyles will help both body and brain to age well.
I recently published a book, “To Tell the Truth: Save Us from Concealment, Half-truths, Misrepresentation, Spin, and Fake News.” It is an inexpensive ($3.99), e-book now available at Amazon. At you can choose among several e-book formats, including pdf.


Klemm, W. R. (2014). Improve Your Memory for a Healthy Brain. Memory Is the Canary in Your Brain's Coal Mine.

Moser, D. A. et al. (2017). An integrated brain-behavior model for working memory. Molecular Psychiatry. Doi: 10.1038/mp.2017.247