Aging is a phenomenon in which various bodily functions degrade with the passage of time. Aging itself is not an illness, but as described in a previous article, aging can trigger various forms of disease. While we have been able to observe the various phenomena that arise due to aging—increases in hypertension and blood glucose level, for example—we have been unable to monitor aging itself. What would be the result if we could find some way to directly measure aging? Here, we learn about the potential of electroencephalography for observing aging as a numeric value.
An era of simple, at-home monitoring through EEG
How can we visualize aging? In our efforts to answer that question, Teijin is currently focusing on electroencephalography (EEG). EEG is a method for recording the electrical activity of nerve cells in the brain. EEG is conventionally performed for medical purposes, such as for the treatment of epilepsy or other specific diseases, but an era in which EEG-based self-care is commonplace may come. This is because EEG devices that allow simple, at-home measurements of brain waves for health maintenance are being developed.
Conventional EEG devices require attaching electrodes across the entire head, a troublesome, time-consuming procedure that has limited their use to medical facilities. However, an Osaka University-based startup called PGV, Inc. has developed a high-precision wearable EEG sensor. This sensor weighs only 27 grams, and it comes in a sheet-like form that can be easily applied like an adhesive bandage. This allows for simple at-home EEG measurements similar to taking your temperature or blood pressure. PGV has applied this device to brain monitoring during sleep and states of excitement, and is performing development toward analyzing the resulting data for use in disease prediction and analysis of emotions.
Can EEG-based self-care activate brain functions?
PGV Chief Scientific Officer, Haruo Mizutani, Ph.D., describes the situation as follows: “EEG analytical values are indicators that classify brain arousal levels. We see completely different recordings when measuring brains in different states—deep sleep, light sleep, awake but relaxed, focused energy and concentration… EEG measurements can likely be applied in many ways, but they have been particularly studied for sleep monitoring. Through daily monitoring of our sleep, we can learn about our sleep patterns and measure how deeply we are sleeping. We believe that brainwaves exhibit patterns unique to the individual, like a fingerprint, but by monitoring our brainwaves and analyzing their state, we may be able to alleviate sleep disturbances and eventually learn to activate our brains.”
It is thought that our brains start aging in our forties or fifties. As abnormal aging substances accumulate within our brain, our cognitive functions gradually decline. Preventing this accumulation is key to preventing deterioration of brain functions, and high-quality sleep is one means to that end. Parasympathetic nerves dominantly work while we sleep, especially in the deep-sleep state called “slow-wave sleep” that appears within around ninety minutes after we fall asleep, and this is the time during which bodily and neural repair work occurs. Indeed, recent research has revealed that elderly people with shorter sleep times undergo increased brain atrophy. We also know that deep sleep durations suddenly decrease in middle and old age. This means that measuring brain activity to grasp our own sleep states and performing self-care aimed at improving sleep quality might help us activate out brains and put the brakes on aging.
“There is a clear correlation between aging and sleep,” Dr. Mizutani says. “If we can use EEG monitoring to accurately measure ratios of deep-sleep time, we will likely come to learn the role that sleep plays in aging phenomena. If we can discover solutions to that end, I believe that it may become possible to slow aging by keeping track of our brainwaves to control deep sleep.”