How should we take on aging as we enter an era of 100-year lifespans? In this exhibition, the aging project team demonstrated measurements of brain age. We also hosted a lecture by Shin’ichiro Imai of the Departments of Developmental Biology and Medicine at Washington University in St. Louis, and PGV Chief Scientist Haruo Mizutani. These guest speakers presented their thoughts on how we might control aging in the future.
How to live a physically and emotionally rewarding life until our final days
Human lifespans have nearly doubled over the past century. We can now expect to live to our eighties instead of until our forties, and this has resulted in significant lifestyle changes. Now that we are heading toward an era of 100-year lifespans , what care should we take to ensure good health until our final days? In its involvement with this project, the aging project team came up with the “life potential curve” as a way of visualizing a life in which both physical and mental health are maintained at high peak levels. Further, nicotinamide mononucleotide (NMN), a target of Imai’s research, is increasingly attracting attention as a substance that may provide a first step in this direction.
The talk began with a description of NMN by Imai. “NMN is converted into a substance called NAD for use within our bodies. NAD is vital to life in all species, from bacteria to humans. We know that enzymes called sirtuins, which play an important role in our body, act on the hypothalamus of our brain to control aging and lifespan. NAD activates these sirtuin proteins, but we know that NAD levels decrease with age. When there is insufficient NAD, sirtuins are no longer activated, causing various problems associated with aging. Aging research is currently proceeding around the world, and NMN is at the center of much of this research. The hope is that we can replace lost NAD by supplementing NMN, and the entire world is waiting for the answer.”
Imai says that we can work toward supplementing NAD in two ways: getting an appropriate amount of exercise every day and living a regular life. “Exercise increases the enzymes that produce NMN. Further, NAD production is controlled by the circadian rhythm, so we think that maintaining our internal clocks is also important. NMN is found in some fruits and vegetables, including soybeans, avocados, and broccoli, so it’s probably best to try to eat those foods. There’s even more NMN present in blood, like the turtle blood that some people drink in Japan. A popular joke among aging researchers is that Dracula’s immortality is probably the result of activate sirtuins from of all the NMN he gets from sucking blood.”
Can brainwaves show us our “brain age”? The hidden potential of brainwaves
The aging project team’s section of the exhibition aimed at considering how we should face aging, and visualizations of aging were one theme within that goal. We demonstrated a high-precision, miniaturized brainwave sensor developed by PGV for measuring “brain age.” Haruo Mizutani, who developed this method for estimating brain age from brainwaves, described how this device can be used.
“Along the lines of what Dr. Imai just said about circadian rhythms, we can measure brainwaves to visualize lifestyle and sleep rhythms. Sleep is known to occur at various levels, from light to deep sleep, and deep sleep is thought to be an important factor for expelling accumulated wastes from the brain. When we compare younger and older subjects, we can see differences in sleep stages by age: young subjects enter deep sleep immediately after falling asleep, while older subjects experience less deep sleep, are awake for longer, and have trouble reaching deep-sleep stages.”
However, not all brain functions deteriorate with aging; some continue to mature as we age. For example, it is thought that we experience peak ability to concentrate at 43, ability to recognize emotions at 48, and vocabulary ability at 67.
“By measuring brainwaves in this way,” Mizutani says, “little by little we have come to understand not only changes in sleep and lifestyle rhythms, but also correlations between aging and brain functions. In the future, we may be able to apply these measurements in various ways, such as disease prevention.”
Imai says that various everyday factors may contribute to delaying aging. Indeed, he suggests that his own dietary practices since 2014 might provide a hint.
“The most important thing in terms of diet is to have a breakfast that helps regulate the daily circadian rhythm. A high caloric intake at the start of the active phase of the day is sensed by neurons in the hypothalamus, which resets the internal clock. In my case, every morning at around 8:00 AM I eat a dinner-sized breakfast, and then at around 8:00 PM I have a simple dinner—usually a glass or two of wine with some fruit and cheese. Then I fast for twelve hours until breakfast the following day. Called intermittent fasting, this is thought to delay aging and extend life. What we eat is important for slowing the speed of aging, but it’s also very important to be conscious of when we eat.”
An age may come in which by visualizing our own brain’s state and our sleep rhythms, we can make objective judgements about how we are aging. If NMN’s antiaging effects on humans can be demonstrated in clinical trials that are currently underway, we may see a future in which we have some control over our aging. In the meantime, we should pay attention to our daily lifestyles, such as getting enough exercise and maintaining a diet that regulates our circadian rhythms. By doing so, we will be able to realize the “productive aging” that Imai advocates. The essence of Teijin’s target for quality of life in the future is a new form of aging that enables all individuals to enjoy a healthy life and to contribute to society. We believe that the key to skillfully coping with aging may be the realization of productive lives in a society of longevity and 100-year lifespans.