"You are as old as you think you are," the saying goes. Well, not quite. You, that is the inner you in your brain, is as old as your brain is. But your brain age may or may not correlate with chronological age.
The other day at my gym workout, I again saw a young black guy, built like Captain America, whose workout schedule sometimes overlaps with mine. We had not met, and out of the blue he came up to me and said, “You are my inspiration. You inspire me to be able to work out like you when I get your age.” Wow! I inspire somebody! Then my balloon popped when I realized that he knew I was old just by looking at me. My body may not look like I’m 83, but I guess hair loss and the lines in my face betray me.
The point of this story is that the bodily organs do not have the same rate of aging. Skin ages rather conspicuously in most older people. Specific organs may age at different rates depending on what they have been exposed to, for example skin and sun, liver and alcohol, lungs and smoking, or fat tissue and too many calories. The brain may age more rapidly than other organs if you damage it with drugs or concussion, or clog its small arteries with high cholesterol, or shrivel its synaptic connections by lack of mental stimulation or not coping with stress.
Is there some biological equivalent to tree rings to show how old your brain actually is? A scientist at the Imperial College in London, James Cole, is developing an interesting approach for estimating brain age. Moreover, the technique seems to predict approximately when you will die.
In the study thus far, MRI brain scans were taken on 2,001 people between 18 and 90 years of age. A computer algorithm evaluated these scans to construct a frame of reference for what is normal for a given age. Then the scans from 669 adults, all born in 1936, were compared against the norms to determine whether the 81 year-old brains were normal for that age.
The people whose brains were older than normal performed more poorly on fitness measures such as lung function, walking speed, and fluid intelligence. They also had increased risk of dying sooner. Predictions became more reliable when the brain-scan data were combined with the methylation of blood DNA, a marker of life experience effects on gene expression.
Another group of workers at UCLA had determined that these kinds of gene changes predict the risk of mortality. This group, headed by Steve Horvath, evaluated these gene expression changes in various tissues of a 112-year-old woman and found that her brain was younger than her other tissues. A "young" brain will help you to live longer and also have a better quality of life.
There are two take-home implications of such research. The first is that lifestyle and environmental influences affect one's age and that not all tissues age at the same rate. The second is that it may now be possible to test which interventions to slow brain aging actually work. We currently think aging brain is slowed by exercise, by anti-oxidants, by healthy diets, by reducing stress. Having objective measures for aging in general and brain in particular will help us decide how well such preventive measures work. There is also the possibility that such measurement tools may help us identify who is aging too fast and why that is happening, which in turn may lead to better therapy.
While we wait on technology, there is one symptom of excessive brain aging we can all notice: memory loss. As the title of my book suggests, memory is the canary in your brain's coal mine.
Get the most out of life as you age. You can slow brain aging by following the advice in Memory Medic's inexpensive e-book, "Improve Your Memory for a Healthy Brain. Memory Is the Canary in Your Brain's Coal Mine." It is available in Kindle at Amazon and all formats at Smashwords.com.
Sources:
Kwon, Diana (2017). How to tell a person's "brain age." The Scientist. May 22.
Cole, James H. et al. (2015). Prediction of brain age suggests accelerated atrophy after traumatic brain injury. Annals Neurology.77(4), 571-581. doi: 10.1oo2/ana.24367. http://onlinelibrary.wiley.com/doi/10.1002/ana.24367/full
No comments:
Post a Comment