Brain Posts on diet and exercise lead the list of topics with the most page views in 2014.

Here are the top five most viewed blog posts. Merry Christmas to all and best wishes for a productive and peaceful 2015.

Clicking on the title will link you to the full Brain Post blog on the topic.

5. Aging, Exercise and Brain Plasticity

This post examined a review of the effects of aging and exercise on the brain. Exercise appears to reduce the rate of atrophy of the brain hippocampus with age. Enhanced brain blood flow with exercise may provide a boost in brain plasticity needed to deal with vascular degeneration.

4. Lo Carb-Mediterranean Diet Combo Sheds Fat in Trial

A research team from Greece published results of a trial of a very low carbohydrate diet alternating with low carbohydrate Mediterranean style diet. Over one year subjects in this study lost an average of 35 pounds. Metabolic changes including lower cholesterol levels were favorable in the study subjects.

3. Alternate Day Fasting for Weight Loss and Cardioprotection

A small study compared a 12 week program of alternate day fasting with control who continued their typical diet. The alternate day fasting group was allowed to eat an evening meal of about 500 calories. The alternate day fasting group lost an average of a pound per week and showed evidence of reduced inflammation including lower CRP levels.

2. Varenicline for Smoking Cessation

In this post, I reviewed four manuscripts relevant to varenicline (Chantix in U.S.) treatment in smoking cessation. Varenicline appears an effective options for treatment of smoking cessation and may be combined with other drug agents such as bupropion. It also appears promising for smokers suffering from a psychiatric disorder when used under the supervision of a physician.

1. How the Body Blocks Effect of Exercise After Weight Loss

The number one post for 2014 examined a study of how the body compensate to weight loss. Weight loss results in a dialing back of resting energy expenditure promoting weight regain. This effect contributes to poor long-term maintenance of weight loss and underscores the needed for continued exercise following weight loss.

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Photo of Christmas Lights at Rhema Church in Tulsa from the author's files. 

Exercise promotes cognitive function in children, adults and elderly individuals.

The mechanism for this effect is unclear. Some of the effect may be due to a general improvement in vascular function and health.

Another potential mechanism is via increased neuroplasticity mediated by neurotrophic factors.

Brain-derived neurotrophic factor (BNDF) is a known contributor to brain neuroplasticity. Levels of BNDF can be determined with serum assays.

RL Leckie and colleagues recently found support for BNDF mediation in an exercise in an interventional study with an elderly population.

The key elements of the design for their study included the following elements.

• Participants: Adults between the ages of 55 and 80
• Exercise intervention: Daily supervised walking sessions beginning with 10 minutes increasing to 40 minutes. Control intervention included stretching and toning sessions lead by an exercise professional
• Cognitive assessment: Task-switching paradigm commonly used to assess executive function
• Blood assay: Serum brain-derived neurotropic factor (BNDF) levels and BDNF genotype
• Statistical analysis: Multivariate linear regression analysis with key dependent variable being cognitive performance after one year of intervention

The main findings from the study included:

• Serum BDNF increased in the exercise group
• This effect was limited to primarily the participants over 70 years of age
• Enhanced executive function following exercise was demonstrated in those over 70
• BDNF level increases in the over 70 age group correlated with cognitive performance

The authors note their does not mean exercise is not important for cognitive function in the younger age group (55-70 years of age). Their study only highlights the age interaction with BDNF in moderating a single executive function task.

BDNF levels decrease with age and the level of decrease in BDNF correlates with reduction in volume of the brain hippocampus. The hippocampus plays a key role in memory function and in decline in memory associated with aging.

It is quite possible that regular exercise after age 70 reduces the age related effect on cognition moderated by BDNF.

Readers with more interest in this study can access the free full text manuscript by clicking on the PMID link in the citation below.

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Leckie RL, Oberlin LE, Voss MW, Prakash RS, Szabo-Reed A, Chaddock-Heyman L, Phillips SM, Gothe NP, Mailey E, Vieira-Potter VJ, Martin SA, Pence BD, Lin M, Parasuraman R, Greenwood PM, Fryxell KJ, Woods JA, McAuley E, Kramer AF, & Erickson KI (2014). BDNF mediates improvements in executive function following a 1-year exercise intervention. Frontiers in human neuroscience, 8 PMID: 25566019

Growing evidence links physical activity to improved cognitive outcome in elderly individuals.

Few studies have examined effects of exercise on those at highest risk for Alzheimer's disease.

J Carson Smith and colleagues recently published a prospective study of a cohort of older adults using structural magnetic resonance imaging.

The key elements of the design of their study included the following elements:
Participants: 97 adults between the ages of 65 and 89
Physical activity level: Frequency and intensity of leisure activity was assessed using the Stanford Brief Activity Survey
Alzheimer's risk status: Assessed using APOE genotype
Brain scanning protocol: Magnetic resonance imaging of brain using a 3T scanner at baseline and 18 months later. The brain hippocampal volume was identified as a key structure involved in APOE-related atrophy and memory decline
Statistical analysis: Participants were grouped in low and high physical activity groups and those with and without high-risk APOE Alzheimer's risk

The research team identified a statistically significant interaction between high-risk Alzheimer's participant and physical activity:

"Hippocampal volume decreased 3% in the High Risk/Low PA (physical activity) group whereas the volumetric changes in the remaining three groups were negligible."

The high-risk Alzheimer's group that participated in higher levels of physical activity appeared to have significant protection against hippocampal atrophy. To reach the higher levels of physical activity in the study they had to endorse one of the following levels:

• Brisk walking 15 minutes daily three or more days per week
• Jogging 15 minutes daily three or more days per week
• Swimming 15 minutes daily three or more days per week
• Moderately difficult chores 45 minutes daily three or more days per week
• Regular jogging, running, bicycling or swimming 30 minutes or more
• Playing sports such as handball or tennis an hour or more 

The authors examine the potential mechanisms for physical activity to reduce hippocampal atrophy in those with the high risk APOE genotype.

They note the beneficial effect of exercise may be through effects on cholinergic function, brain lipid metabolism or reduced neuroinflammation.

If this study is replicated it is an important finding with several implications.

One implication is that it may be one of the first research findings to support routine genetic testing for APOE and Alzheimer's risk. Those identified as high risk by APOE status could be targeted for aggressive behavioral interventions to increase physical activity along with increased surveillance of cognitive function.

Readers with more interest in this research can access the free full-text manuscript by clicking on the PMID link in the citation below.

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Photo of roseate spoonbill at sunset is from the author's files.

Smith JC, Nielson KA, Woodard JL, Seidenberg M, Durgerian S, Hazlett KE, Figueroa CM, Kandah CC, Kay CD, Matthews MA, & Rao SM (2014). Physical activity reduces hippocampal atrophy in elders at genetic risk for Alzheimer's disease. Frontiers in aging neuroscience, 6 PMID: 24795624

Happy New Year to All! Hoping everyone has a healthy, happy and productive year in 2015.

I have been working on a topic list for 2015. I will be following my pattern of focusing on a specific brain research topic each month.

During the month I will post primarily on that topic after reviewing relevant research abstracts and manuscripts.

The topic list is taken from areas showing the most reader interest as well as covering area not recently reviewed.

I occasionally post off topic when a specific issue of importance arises.

The topic outline for 2015 will be:
January: Diet, Weight Loss and the Brain
February: Exercise
March: Parenting
April: Attention deficit disorder
May: Conduct disorder
June: Alzheimer's disease
July: Bipolar disorder
August: Social anxiety disorder
September: Migraine headaches
October: Neuropsychology
November: Brain imaging
December: Genetics

Brain Posts aims to select brain research relevant to translation to better clinical care for brain disorders.

Additionally, the blog provides an incentive for me to continue reading, learning and trying to keep up with key brain research advances.

Today's photo is from my files of an edited photo from the Rhema church Christmas lights.

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