by Buck Institute
December 11, 2019 . BLOG
Cognitive Fitness: Help your brain look great in spandex
By Eric Verdin, President and CEO of the Buck Institute
If your doctor told you there was a pill you could take that that would decrease your risk of dementia by up to 50%, and the side effects included reduced body weight and improved heart health, what would you do? I think we all know the answer to that hypothetical. Unfortunately exercise doesn’t come in pill form quite yet!
But ask yourself: what does being fit mean to you? You might exercise to lose weight. Or your focus could be on building muscle. Others may focus on endurance. Each type of fitness requires its own specific exercise regime. Now there is growing evidence that focusing on brain health might require its own specialized type of exercise.
In the spring I wrote about exercise as an overall strategy to promote healthy aging. Today I want to drill down a bit more here to focus on the relationship between exercise, cognitive health, and dementia. This is a very promising area of research.
It might not be intuitive that exercise is good for the brain. After all, working out moves the body, but the brain isn’t exactly doing hard labor when you’re on that rowing machine. It turns out, however, that exercise seems to act through a variety of biological mechanisms to support cognition. Studies in both mice and humans show that exercise supports neuron growth by increasing the production of a key factor that our nerve cells just love: brain-derived neurotrophic factor (BDNF). It also increases blood flow to the brain, which brings vital nutrients and oxygen. There is also interesting work showing that regular exercise changes which genes get turned on and off (epigenetic changes), resulting in an overall healthier epigenetic profile. Bottom line: exercise has measurable biological effects on the brain, and all these changes are for the better.
So how do these positive changes translate when it comes to aging and age-related disease? Simply put, the changes make your brain work better by delaying cognitive decline associated with aging, and potentially even delaying the onset of dementias like Alzheimer’s disease. A recent article in the New York Times highlights results from two recent studies. One study used long-term data from a Norwegian dataset. It found that not only was there a reduced incidence of dementia in a cohort that maintained fitness over time, there was also a reduced incidence in those who were not as fit but set out to improve their fitness over time. People who moved from unfit to fit over time saw a 48% risk reduction in dementia incidence, and delayed the onset of dementia by more than two years. They also seemed to increase their average lifespan by about the same amount. This is a great reminder that it’s never too late to start exercising.
The really exciting science is coming as we learn specifically what kind of exercise is best for brain health. The other study described in the New York Times looked at exactly this question. Researchers at McMaster University collected a group of sedentary adults over 60 years old as study participants and randomly assigned them to three different exercise regimes: stretching (as a control group); steady treadmill walking; and high-intensity interval treadmill walking. After 12 weeks, only the group assigned to the high-intensity interval training showed overall improvements in memory performance.
Another interesting association from this study is that, even within the high-intensity group, increased fitness was correlated with increased cognitive function. That is, the more that someone’s cardiovascular fitness improved, the more their cognitive function improved. There is also good evidence that resistance training has memory-boosting benefits. Older adults with Mild Cognitive Impairment had improved memory after a 6-month strength-training course, relative to a control group.
So what is the lesson here? It seems that pushing yourself and working up a bit of a sweat is key to gaining cognitive benefits from exercise. A walk around the block or easy stretching simply don’t seem to confer the same benefits. This is not to say that you must run uphill until you collapse to do it right. Everyone is at a different starting point, and different amounts of exercise will be “pushing it” for different people.
What the data does tell us is that fitness is training your mind as much as it is training your body. Keep up with it as much as you can, and try to increase the intensity of your exercise as you get fitter. It’s likely that you can’t just pick one workout and stick with it indefinitely. Once it becomes too easy you will likely need to up it a bit to gain and maintain cognitive benefits. And remember that any movement is better than none. Even if you can’t work yourself up to a sweat regularly, there are overall health benefits to getting just 4,400 steps a day, with increasing benefits up to about 7,500 steps. While there will always be exceptions, movement is the single best healthy aging tool we have.
Finally, remember, a prescription for exercise is free, has virtually no negative side effects, and doesn’t require FDA approval. With most medications, there is consideration over whether a specific prescription is appropriate. For example, are statins the right choice? Are the side effects of one drug worth the benefits it can provide? Additionally, each drug goes through many years of testing before it is demonstrated safe and effective and can be approved. This is not the case with exercise. Are you wondering if you should do it? The answer is yes!! And you can start right now! Literally, the rest of this blog post is not important relative to the benefits of exercise. Put down your phone, step away form the computer, and start moving!
For those of you still reading, thanks for your dedication to my blog! NOW go exercise!