A little food for thought

The average retirement age of a physician is between 67-74 years of age. Of those physicians who leave full time work, 40% will continue with some part time medical practice. The overall average life expectancy in the US is 79.3 yrs (F-81.6, M-76.9). That means life will end for 50% of all adults at that age … however 50% will continue to live, maybe for many more years. College graduates also tend to have a greater than 8 year life expectancy over their counterparts (making up a significant portion of the latter half on the Gaussian curve). There are things beyond our control that will impact our mental health and longevity including genetics, family history and acute medical illness. However, the odds are we will be around for a few more election cycles.

Abnormal brain aging

Dementia is defined as the loss of cognitive capacity to the detriment of social functioning and individual living that lasts longer than 6 months. Though memory loss is an early component of this disorder, other symptoms include executive functioning, language difficulties, working (immediate) memory, spatial memory and visual memory. The risk of someone getting dementia at age 65 is 1:70. This increases to 1:5 by age 85.

There are many causes of dementia, the most well-known being Alzheimer’s disease. Alzheimer’s and vascular dementia account for a large percentage of severe onset dementia.

Dementia and the normal aging brain

Dementia is not considered the normal process of brain aging. However, it is clear that the normal aging process also demonstrates progressive functional losses in perception, cognition and memory. A growing body of evidence seems to suggest a down-regulation of neuromodulatory system functions and increasingly poor signal–to-noise conditions (getting lost in the process). Traditional thought was that the machinery of thinking simply wore down (Mahnke et al , 2006). It has been shown that four core biological factors may contribute to normal brain aging.

  1. Reduced schedules of brain activity (going through the motion)
  2. Noisy processing (inability to filter),
  3. Weakened neuromodulatory control
  4. Negative learning (lack of input).

These combined components may produce “negative” brain plasticity and a decrease in function.

Teaching an old dog new tricks

The hippocampus and the parahippocampal area, a key memory region, has been shown to decrease in size with age (a normal occurrence)(Raz et al 1998). White matter changes have also been seen on MRI studies with increasing memory loss (Madden et al 2009). Despite these normal physical changes, the brain has the ability to alter its functional capacity throughout life both in a negative and positive manner. For example, the same group of patients who demonstrated an age related decrease in size of the hippocampus actually showed a subsequent increase in size with simple exercise for 6 months (AARP Bulletin, 2016). There are numerous stories of patients with traumatic brain injuries leading to impairment of motor function (Doidge “the Brain that changes itself”, 2003). Over time, these patients were able to regain function by diverting the brain activity to another area of the gray matter.

The idea of improving brain function by taking advantage of this unique ability of the brain to “respond ” has created much interest in an attempt to provide tools to counter the normal aging brain and prevent the onset of dementia. We will discuss several of these recommendations in later sections. 

“…Can’t Remember…” What is really going on?

Several studies have shown consistent areas of decreased function with normal brain aging. Of these, a decrease in speed of the cognitive process was the most consistent change in the aging brain (Birren 1965, Woods 1980, Cerella 1985, Salthouse 1996). This was related to an increase in the deletion of random links in the memory network creating a much longer memorial processing pathway (Craik 1982, Rabinowitz 1982).

Deficiencies in two important mechanisms were outlined :

  1. “Limited time mechanism” in which the older adult has a more difficult time performing higher-level operations within an allotted time.
  2. “Simultaneity mechanism” – decreased ability to consider concurrent task-relevant components because of the loss of earlier processing pathways (Salthouse et al 1996). Interestingly this correlated with findings that suggested the difficulty of the aging brain to filter irrelevant material, subsequently interfering with the primary task. Again speed of processing was the most age-related variance in cognitive tasking (salthouse 1985a, 1985b, 1996). However, the task was eventually accomplished in this group if time demands were eliminated. It is easy to understand how important these capacities are to the ability of the physician to provide patient care, especially in complex or urgent situations.

Is it a one way street?

As the process of cognitive aging has been better understood, it is predictable that the question of reversibility and maintenance would be explored. With the assistance of environmental support (contextual guidance, mental crutches), memory was found to be improved with trigger words or phrases (vitally important in the case of my ever-changing CHOA password) (Craik 1986, 1987, Smith 1977). Familiarity of the situation or the physical surroundings was also critical to minimizing age deficits (Craik 1994, Park 2000).

Numerous studies have shown the effectiveness of structured mental training programs in which prolonged cognitive exercises over 6 months demonstrated significant improvement in function (…Could this be (gulp) the argument for recertification?) (Mahncke 2006,Shaffer 2016, Mahncke Connor 2006). The hypothesis is that the use of structured brain exercises in an aging population can be utilized to create positive brain plasticity and potentially prevent or delay the need for expensive assisted living needs.

Specific repetitive functions (albeit with constant changing parameters .. think patient care) within a daily activity can also elicit positive physical changes in the brain. For example, London cab drivers had larger hippocampi than London bus drivers because of the need of the former to constantly assimilate new information and create complex spatial information to navigate routes (Maguire 2006). Bus drivers obviously took repetitive routes. Bilinguals were also noted to have changes in the brain compared to monolinguals, specifically an increase in the left inferior parietal cortex (Mechelli et al 2004). Professional musicians also demonstrated a significant increase in gray matter over non-musicians (Gaser et al 2003). Even studying for exams produced changes in the parietal cortex of medical students before and after a test (Draganski 2006).

Maintaining

Maybe even more relevant than compensation of brain function is the idea of maintaining cognitive health. It is clear that there are certain activities that have been shown to decrease the chance of dementia and maintain a high level of cognitive function. Four recurrent areas of discussion include:

  1. Mental stimulation
  2. Physical exercise
  3. Control chronic health issues
  4. Nutrition

Mental stimulation

So do those sudoku puzzles really help? The answer is maybe not so much but the more important answer is that it is critical to constantly challenge your brain activity. New input is the key. Here are some ways to “poke” at your brain.

Studies have shown that reading is a “whole brain activity “(Stine-Morrow 2015).  Reading at an early age and being an avid reader as an adult has been shown to be very impactful for brain health, especially articles that may challenge set ideas or introduce new interests. Music has also been shown to be extremely ‘brain healthy” in particular,  listening to new music outside your comfort zone (Yes, your child’s Hip hop)(www.hopkinsmedicine.org). In any of these events, one should be challenged to think “top –down”. Engage in dissecting what has been read or heard, dig deeper into the material. “Zoom out, then zoom in”

Social group identity and interaction has been shown to be critical for cognitive health, even more than individual connections (Haslam et al 2016). Family, religious or professional/ special interest groups can serve this role. Interacting on social media may also help!! A recent study showed a significant benefit for complex working memory in a group who were given the task to learn and use Facebook compared to their cohorts who did not. A dramatic difference was noted in cognitive testing between the two groups (Myhre et al 2016) . Nothing about dating sites was mentioned.

Sustained engagement in a new activity has shown to be one of the most promising tools in maintaining and improving cognitive function (Park et al 2013). A study group was assigned a new skill acquisition (quilting and digital photography) for several nights a week over three months. This group demonstrated a significant improvement in cognitive thinking.  Acquiring a second language, attending night classes, learning the salsa or any new activity that involves a period of months to years are equally effective.

How about brain teasers?  They are a good workout for the brain but target very specific cognitive abilities that do not necessarily transfer to thinking or problem solving (Held , http://time.com) Again, novelty is extremely important to brain health. Recent “brain apps“ for the cellphone may provide new and different tasks to fill a few minutes (Santanachote 2014).

Included are five brain apps considered to be the best:

  1. Luminosity
  2. CogniFit Brain Fitness
  3. Personal Zen
  4. Brain trainer special
  5. Brain Fitness Pro

Physical activity

Physical activity is on the top of almost every list of recommendations to maintain brain health and prevent dementia.

Regular exercise  (aerobic and anaerobic) has been shown to provide many gains including general health, control of chronic medical conditions and stress relief. Exercise has also been shown to actually increase blood vessels in the brain and increase synaptic communication (held 2014, health.harvard.edu). Sleep should be listed under physical activity. Sleep deprivation has been shown to decrease brain plasticity (Kuhn et al 2016). Adequate sleep provides recalibration and improves synaptic plasticity possibly through a plasma protein (BDNF). To “sleep on it” may be very good advise.

Chronic illness

Along with physical activity, the second most common factor that decreases the likelihood of dementia is control of chronic health issues (Harvard health edu). These include high blood pressure, high cholesterol, diabetes, sleep apnea, depression and hypothyroidism. Included is also abstinence from tobacco and limited alcohol consumption. Also mentioned was the prevention of traumatic brain injuries (Harvard edu).

Nutrition: Brain food

There is obviously a close relationship with all of the above-mentioned areas and nutrition. We can eat to keep the brain happy (Edwards  www.selfgorwth.com).

  1. Water – adequate hydration is critical for maintaining a healthy brain. Chronic or recurrent dehydration can often lead to headaches and fatigue.
  2. Oxygen – Eating large meals will divert oxygen away from other areas of the body including the brain (postprandiol nap attack). Small and frequent meals may provide better overall daily function.
  3. Foods
    1. Neurotransmitters
      1. Acetylcholine –(movement, thinking, memory) –egg yolks, peanuts, wheat germs, meat , fish, milk, vegetables and cheese
      2. Dopamine (emotional arousal) –   meat, milk products, fish, beans, nuts soy (3-4oz of protein/day)
      3. Serotonin  (arousal , sleep, mood , appetite) – pasta, starchy vegetables, potatoes, breads, cereals
    2. Proteins – 3-4 oz. per day
    3. Carbs – enhances absorption of tryptophan.  – grains, fruits, vegetables
    4. Fat – Omega 3 fatty acids –salmon, tuna sardines, flax seed
    5. Vitamins – B vitamins (folic acid, B6, B12)  can help lower homocysteine levels , high levels have been linked to increased risk of dementia. Also antioxidants A,C and E.

“The Finish Line”

A well-known bumper sticker reads:

“If you didn’t know how old you were, how old would you guess?” Cognitive health is an area that brings together the physical components of our lives (nutrition, exercise, control of medical conditions, etc.) with our mental health (stress -control, mindfulness, humor).

Several things are obvious.

  1. We have a much longer road to travel before we cross the finish line than our predecessors, especially as functioning physicians.
  2. There are concrete things that we can do to provide the best chance that our journey continuous to be productive and engaging.
  3. These activities require a commitment that begins “yesterday” and continuous for the rest of our lives.

Hope this created a little “brain sweat” for you.

Dr. Williams is also the Children’s Chief of Plastic and Craniofacial Surgery and is a member of the Children’s Board of Trustees.