Quote: Exercise and the brain

The implication is that exercising during development, as your brain is growing, is changing the brain in concert with normal developmental changes, resulting in your having more permanent wiring of the brain in support of things like learning and memory. It seems important to [exercise] early in life.

David Bucci 
How Exercise Affects the Brain: Age and Genetics Play a Role

This Mother’s Day give the gift of brain health

University of British researcher Teresa Liu-Ambrose, PhD, P.T. and her associates published a study in the April 23 Archives of Internal Medicine that revealed older women improved mild problems in thinking and memory by performing resistance exercises. Megan Brooks, writing for Medscape Medical News, summarized the study:

Six months of twice-weekly resistance training (RT) improved executive function, associative memory, and regional patterns of functional brain plasticity in a group of older women with probable mild cognitive impairment (MCI).

In previous work, Liu-Ambrose had reported “improved executive function in cognitively healthy older women” who performed resistance exercises twice a week for one year. The current study suggests an even more powerful effect of resistance training: it can improve mild cognitive dysfunction in just six months.

Maybe this Mother’s Day, consider taking mom to the sporting goods store for some barbells.

Even more good news for mom (and dad)

Image: istockphotoIn addition to resistance training, daily activity is also important for maintaining brain health. A recent study published in the April 24 issue of Neurology found daily physical activity reduces the risk of developing Alzheimer’s disease. Nicholas Bakalar, writing for The New York Times, notes the study:

….included 716 people, average age 82, without cognitive impairment. Each wore a wrist actigraph, a device that measures movement, for about 10 days to establish his or her usual level of daily physical activity. Over the next four years, 71 of them developed Alzheimer’s.

The research found those performing the highest level of physical activity reduced their risk of developing Alzheimer’s disease by half compared to those that were the least active.         

Maybe it’s is time to put the computer down and take mom and dad for a walk. If they have passed on as my parents have, walk in their memory.

Brain Health: Omega-3 fatty acids slow brain shrinkage

New research is revealing the benefits of omega-3 fatty acids on brain health, in particular, on reducing loss of brain volume associated with ageing. This recent news report (PubMed abstract not yet available), adds to previous work by measuring the level of O3 in the subjects red blood cells over a 3-month period and correlating it to total brain volume as measured on MRI. The study of 1,575 subjects compared the brain MRI scans of the 25% with the lowest level of O3 to the rest of the group. According to the WSJ:

… participants with low levels of omega-3 fatty acids in their blood had slightly smaller brains and scored lower on memory and cognitive tests than people with higher blood levels of omega-3s. The changes in the brain were equivalent to about two years of normal brain aging…

The study is important because of its large size and because the subject’s O3 levels were measured instead of utilizing food diaries for an estimate of O3 intake. However, a more interesting, and perhaps revealing question would have been comparing the subjects in the lowest quartile to those in the highest quartile. This may have revealed omega-3 fatty acids provide an even greater protection from brain volume loss than the two years in the study.

Bottom line: To prevent or slow brain shrinkage, eat your fish or take an omega-3 supplement.

Related Posts

• Brain Health: Omega-3 fatty acids reduce anxiety
• Quote: Adiposity causes inflammation of the hypothalamus
• Inflammation impairs frontal lobe brain function
• Brain Health: Fish oil helps maintain brain volume
• An "Insight of the Decade": Chronic inflammation kills

Update 3/2/2012
Abstract of study published in Neurology

Quotes: High carb diet and Alzheimer's Disease

 In this paper, we highlight how an excess of dietary carbohydrates, particularly fructose, alongside a relative deficiency in dietary fats and cholesterol, may lead to the development of Alzheimer's disease.”

This leads to cholesterol deficiency in neurons, which significantly impairs their ability to function.”

Other neurodegenerative diseases ... may also be due in large part to this same underlying cause.”

Nutrition and Alzheimer's disease: The detrimental role of a high carbohydrate diet. 
Eur J Intern Med. 2011 Apr;22(2):134-40

Quote: Adiposity causes inflammation of the hypothalamus

Adiposity is associated with chronic low-grade systemic inflammation and increased inflammation in the hypothalamus, a key structure in feeding behavior.

Obesity-mediated inflammation may damage the brain circuit that regulates food intake. Brain Res. 2011 Feb 10;1373:101-9. 

In other words, excess fatty tissue in obesity harms the hypothalamus, the brain structure that regulates feeding behaviour, and makes it more difficult to control overeating. Through inflammation, excess fatty tissue takes control. The solution, a non-inflammatory diet such as the Paleo diet. 

Related links:

• An "Insight of the Decade": Chronic inflammation kills
• Inflammation impairs frontal lobe brain function
• Brain Health: Omega-3 fatty acids reduce anxiety
• The microenvironment: “… an entirely new way of thinking about cancer”

Brain Health: Stay smart with exercise

By Dr. John

The authors of a new report published in the Mayo Clinic Proceedings reviewed 1,600 articles on the role exercise in cognitive function and found 130 studies pertinent to the issue. According to Medscape Neurology, the lead author, neurologist J. Eric Ahlskog, MD, PhD, notes:

Normal aging is associated with brain shrinkage, and this appears to be primarily mediated by progressive loss of synapses and related neuronal connections (the 'neuropil').

Dr. Ahlskog summarized the findings: 

We concluded that you can make a very compelling argument for [aerobic] exercise as a disease-modifying strategy to prevent dementia and mild cognitive impairment, and for favorably modifying these processes once they have developed.

While the type and amount of exercise varied among the studies, to Dr. Ahlskog, the studies suggests increasing "the heart rate to about 60% of maximum" in several sessions for a total about 150 minutes each a week. Even though the literature on resistance training was "less extensive", Dr. Ahlskog noted it was also beneficial. Cyrus Raji, MD, PhD of the University of Pittsburgh, not a participant in the study, concurred: 

While the majority of the evidence shows that aerobic physical activity is the best type of physical activity for this purpose, resistance training with weights may also be helpful.

Dr. Raji's impression of the study:

This paper nicely summarizes all of the latest evidence showing how regular physical activity can promote better brain health with aging and reduce the risk of Alzheimer's disease.

Brain Health: Fish oil helps maintain brain volume

By Dr. John

The first signs of human consciousness were found in Blombos Cave, South Africa and date to 70 to 80 thousand years ago. It is probably no accident that the site is littered with evidence of seafood consumption. Indeed, significant inclusion of seafood and fish in the human diet may represent the final nutritional factor in development of the human mind. 

The typical American diet is profoundly different from that of our Paleolithic ancestors and is increasingly considered the root of many modern diseases.

In a new study reported by EurekAlert, researchers at Rhode Island Hospital's Alzheimer's Disease and Memory Disorders Center revealed older adults taking fish oil supplements preserved brain volume and had smaller cerebral ventricles (a healthy sign suggesting less brain atrophy). Lead investigator, Lori Daiello, PharmD, states:

"In the imaging analyses for the entire study population, we found a significant positive association between fish oil supplement use and average brain volumes in two critical areas utilized in memory and thinking (cerebral cortex and hippocampus), as well as smaller brain ventricular volumes compared to non-users at any given time in the study. In other words, fish oil use was associated with less brain shrinkage in patients taking these supplements during the ADNI study compared to those who didn't report using them."

This observational study is just one additional piece of evidence demonstrating our continued movement away from the original human diet comes at a price. In this case, a shrinking brain. 

Related Posts
The Standard or Average American Diet  
Inflammation impairs frontal lobe brain function 
Brain Health: Omega-3 fatty acids reduce anxiety
Loren Cordain - Origins and Evolution of the Western Diet 

Brain Health: Omega-3 fatty acids reduce anxiety

Salmon is an excellent source of anti-inflammatory omega-3 fatty acids. Select wild-caught Alaska salmon to reduce environmental impact.By Dr. John

The typical American diet, based largely on grains, added sugars and fats, and dairy, is pro-inflammatory. Recent studies suggest low-grade chronic inflammation affects neurological function, including the frontal pathways of the brain.

On July 19, a research study published in Brain, Behavior and Immunity revealed dietary omega-3 fatty acids decrease anxiety by reducing inflammation.

The randomized controlled 12-week trial included 68 volunteer medical students. Half received omega-3 supplementation and the other half, placebo. Psychological surveys measuring anxiety, stress, and depression, and blood samples measuring inflammatory cytokines were obtained "during lower-stress periods as well as on days before an exam." As reported by EurekAlert, even though the school had changed its curriculum by eliminating the stressful clustering of medical exams over a 3 day period, students "receiving the omega-3 showed a 20 percent reduction in anxiety compared to the placebo group." There was no change in depressive symptoms.

The reduction in anxiety appears to be modulated by a decrease in cytokines. Students taking the omega-3 supplements had a 14% reduction in the cytokine interleukin-6. The study concluded:

These data suggest that n-3 supplementation can reduce inflammation and anxiety even among healthy young adults. The reduction in anxiety symptoms associated with n-3 supplementation provides the first evidence that n-3 may have potential anxiolytic benefits for individuals without an anxiety disorder diagnosis.

So, are you stressed or anxious? Stick to the Paleo diet to reduce brain inflammation. Eat plenty of fish. Still anxious? Supplement with omega-3. 

Links

• Omega-3 supplementation lowers inflammation and anxiety in medical students: A randomized controlled trial. - PubMed
• Omega-3 reduces anxiety and inflammation in healthy students - EurekAlert
• The Standard or Average American Diet - PaleoTerran 
• Inflammation impairs frontal lobe brain function - PaleoTerran
• An "Insight of the Decade": Chronic inflammation kills - PaleoTerran

Inflammation impairs frontal lobe brain function

One of the great advantages of the Paleolithic diet when compared to the SAD (Standard American Diet) is the normal balance of omega-3 and omega-6 fatty acids. While both are important for health, the ratio of the two should be in balance with roughly equal amounts of O-3 and O-6. As Jonny Bowden, PhD, CNS writes -

Now if you go back and look at the diet of all the hunter-gatherer societies, the “natural” diet of Paleolithic man, and the basic diet of any civilization that lived off the land, eating unprocessed and unrefined foods, you find an interesting relationship between the consumption of the two types of fatty acids: It was always in balance. 

Now consider the SAD diet: the ratio of O-3/O-6 is 1/15! And that is a conservative estimate. The inflammatory omega-6 fatty acids are much higher than the anti-inflammatory omega-3 fatty acids. As Artemis P. Simopoulus of the Center for Genetics, Nutrition, and Health in Washington DC notes - 

A very high omega-6/omega-3 ratio, as is found in today’s Western diet, promotes the pathogenesis of many diseases, including cardiovascular disease, cancer, osteoporosis, and inflammatory and autoimmune diseases. 

In addition to contributing to the development of these diseases, evidence is building that inflammation also affects brain function. In the March 30, 2010 issue of Neurology, H Wersching and colleagues detail their research on the effects of inflammation on higher-level thinking called executive function, specifically on planning, decision-making and self-control. The researchers measured high-sensitivity-C-reactive protein, a marker of inflammation, in 447 persons (average age of 63 years) without a history of stroke. High-field MRI scans of the brain were obtained in 321 of these. Sophisticated measures of brain integrity were performed including "fluid-attenuated inversion recovery sequences for assessment of white matter hyperintensities, automated quantification of brain parenchyma volumes, and diffusion tensor imaging for calculation of global and regional white matter integrity, quantified by fractional anisotropy (FA)."

The subjects with high C-reactive protein, thus inflammation, had evidence of "cerebral microstructural disintegration" primarily affecting the "frontal pathways and corresponding executive function", clear evidence that inflammation disrupts frontal brain processes. 

Time for more vegetables.

Related Entries:
An "Insight of the Decade": Chronic inflammation kills
Are mainstream nutritionists beginning to recognize the value of Paleolithic nutrition?