Start Your Engines!

By Karen and Erica

When we were a bit younger, we expected to spend our short post-career lives doing very little except sitting in rocking chairs, reading novels, munching on bonbons and sipping martinis. We would be old and tired, our time horizon would make serious efforts at fitness irrelevant, and a couple of years of total self indulgence was all that would be left for us before we ascended to the pearly gates.

Then we grew up.

• We learned that we might have thirty years to live after we retired. 
• We learned that our minds would continue to be active during those thirty years–if we took care of ourselves and disease did not intervene.
• We learned that our bodies would keep functioning during those thirty years–if we took care of ourselves and disease did not intervene.

We had to give up the fantasy of a short, self-indulgent post career interlude, and replace it with a long, energetic, new lease on life. Actually, a pretty exciting exchange. Except now we had to do something if we wanted our longer lives to be mobile and sentient.

Our longer lives are a gift, but living longer with dementia is not part of the plan–if we can help it. 

While more than 55 million people worldwide are living with dementia, and that number is expected to rise to 78 million by 2030 and 150 million by 2050. There have been notable advances in drug treatments that can help slow the progression of different types of dementia—including Alzheimer’s disease, which is the most common form of the condition—but there is no specific cure to reverse a dementia diagnosis. 

And, at least to seopme extent, we can help it. Exercise! We read recently in the New York Times’ 5-Day Brain Health Challenge:

“Exercise is top, No. 1, when we’re thinking about the biggest bang for your buck,” said Dr. Gregg Day, a neurologist at the Mayo Clinic.

Numerous studies have shown that people who exercise regularly tend to perform better on attention, memory and executive functioning tests. There can be a small cognitive boost immediately after a workout, and the effects are sustained if people exercise consistently. And while staying active can’t guarantee you won’t develop dementia, over the long term, it is associated with a lower risk of it.

Researchers think that moving your muscles benefits your brain in part because of special signaling molecules called exerkines. During and after a workout, your muscles, fat and other organs release these molecules into the bloodstream, some of which make their way up to the brain. There, those exerkines go to work, helping to facilitate the growth of new connections between neurons, the repair of brain cells and, possibly, the birth of new neurons.

Exercise also appears to improve blood flow in the brain. That ramps up the delivery of good things to brain cells, like oxygen, glucose and those amazing exerkines. And it helps remove more bad things, namely toxic proteins, like amyloid, that can build up and damage brain cells, increasing the risk for Alzheimer’s.

All of the changes brought on by exercise are “essentially allowing your brain to age more slowly than if you’re physically inactive,” said Kirk Erickson, the chair of neuroscience at the AdventHealth Research Institute.

We never heard of exerkines before, but they seem to be important to maintaining the complex organisms that are our bodies running smoothly. 

Exerkines are defined as signalling moieties released in response to acute and/or chronic exercise, which exert their effects through endocrine, paracrine and/or autocrine pathways. A multitude of organs, cells and tissues release these factors, including skeletal muscle (myokines), the heart (cardiokines), liver (hepatokines), white adipose tissue (adipokines), brown adipose tissue (baptokines) and neurons (neurokines). Exerkines have potential roles in improving cardiovascular, metabolic, immune and neurological health.

Probably better to have been exercising all along, but even if you are slothful, like us, there is hope.

Research has shown that people who take regular exercise may be up to 20% less likely to develop dementia than those who don’t take regular exercise. This came from some analysis that combined the results of 58 studies into exercise and dementia.

It has been shown that going from being inactive to doing some amount of exercise has the biggest impact. Sustaining physical activity throughout midlife also seems to have the best effect on reducing dementia risk. 

Happily, even as we get older, we can start moving 

Published in JAMA Network Open, the study found that exercising during midlife from ages 45 to 64 may lower dementia risk by 41 percent, while exercising during late life from ages 65 to 88 could lower this risk by 45 percent. The intensity of physical activity mattered during midlife, with high-intensity exercise yielding the lowest risk of dementia, but the researchers did not observe a difference in risk based on exercise intensity among older adults. 

And apparently we do not need to spend our entire day exercising, though more is better.

The researchers found that engaging in as little as 35 minutes of moderate to vigorous physical activity per week, compared to zero minutes per week, was associated with a 41% lower risk of developing dementia over an average four-year follow-up period. Even for frail older adults—those at elevated risk of adverse health outcomes—greater activity was associated with lower dementia risks. 

The researchers found dementia risk decreased with higher amounts of physical activity. Dementia risks were 60% lower in participants in the 35 to 69.9 minutes of physical activity/week category; 63% lower in the 70 to 139.9 minutes/week category; and 69% lower in the 140 and over minutes/week category. 

We take these admonitions seriously, and we are making at least some efforts at moving for some part of most days. Apparently, 10,000 steps a day are not necessary, and walking that much takes some time, so we often combine walking with grocery shopping or some other chore. And we know weight exercises are also critical, so we spend time in the gym. We don’t always enjoy it–though usually we feel better once we do it. And since we need to exercise to keep thinking, then we guess we should do it.

So get out there, ladies, and start your engines.  

Tell us how it goes!