A new way to optimize sleep and light exposure can reduce jet lag and improve alertness
Wearable technology can be used to calculate optimal personalized sleep and light schedule
December 18, 2019
Science Daily/Rensselaer Polytechnic Institute
Researchers explain how they have developed and demonstrated a series of algorithms that can analyze biometric information recorded by a smart device and then recommend the best combination of sleep and light to help a person readjust their circadian rhythm.
Whether you're traveling for work or for fun, nothing ruins the start of a trip quite like jet lag. Engineers affiliated with the Lighting Enabled Systems & Applications (LESA) Center at Rensselaer Polytechnic Institute have developed a way to deliver personalized advice using smart wearable technology that would help travelers adjust more quickly.
In a series of articles, including one published today in PLOS ONE, the researchers explain how they have developed and demonstrated a series of algorithms that can analyze biometric information recorded by a smart device and then recommend the best combination of sleep and light to help a person readjust their circadian rhythm.
"Using these algorithms and a mathematical model of a person's circadian rhythm, we have the ability to compute the best light to adjust your circadian rhythm and foster your well-being. This opens the opportunity to create a smart and healthy environment," said Agung Julius, an associate professor of electrical, computer, and systems engineering at Rensselaer and one of the authors on this paper.
The same, he said, goes for determining the sleep -- both how much and when it should be received -- a person needs.
Circadian rhythms are master internal clocks that help regulate many of our physiological processes, including sleep, metabolism, hormone secretion, and even how our brain functions. Energy, alertness, and other biological processes can suffer when that rhythm doesn't align with the clock one is actually trying to follow.
The Department of Defense is funding this research because of the benefits the researchers' findings could bring to the alertness of service members.
"The circadian and sleep processes are also very tightly related to your mental state and how alert you are," Julius said. "If you try to do something in the wrong time of day, your alertness is not going to be as effective as if you do it in the right time of day as defined by your circadian clock."
Julius explained that a person's circadian rhythm variation is typically determined using information gathered from a blood or saliva test that measures levels of the hormone melatonin. The problem with that traditional approach is that obtaining the results takes time and doesn't allow for instant analysis.
The LESA team, which includes John Wen, head of the Department of Electrical, Computer, and Systems Engineering at Rensselaer and co-author on this paper, has been working on algorithms that process data -- like heart rate and body temperature -- that can be collected from wearable smart technology and converted into an estimate of a person's circadian rhythm variation.
"The question is whether that kind of data can give you as accurate an estimation as the clinical standard," Julius said.
What the team has found and demonstrated is that the estimates their algorithms generated are in line with clinical hormone measurement techniques. Julius said these findings are indicative that the team's approach works.
"This work is important, because it characterizes the fundamental processes the human body uses to synchronize circadian and sleep processes. By developing biosensing analytics to characterize circadian phase, it is now possible to optimize the efficient use of light with appropriate spectral properties to help optimize and maintain human health and performance," said Robert Karlicek, the director of the LESA Center. "This will be important to other work related to lighting and health in LESA's clinical research test beds at Thomas Jefferson University and the University of New Mexico."
https://www.sciencedaily.com/releases/2019/12/191218153325.htm
How eating feeds into the body clock
April 25, 2019
Science Daily/Medical Research Council
New research has found it is not just what you eat, but when you eat that is important -- knowledge which could improve the health of shift workers and people suffering from jet lag.
The Medical Research Council (MRC)-funded study, published today in the journal Cell, is the first to identify insulin as a primary signal that helps communicate the timing of meals to the cellular clocks located across our body, commonly known as the body clock.
The team behind the research believe this improved understanding may lead to new ways to alleviate the ill-health associated with disruption to the body clock. These could include eating at specific times or taking drugs that target insulin signalling.
The body clock -- also known as the circadian rhythm -- is a 24-hour biological cycle that occurs individually in every cell of the body, driving daily rhythms in our physiology, from when we sleep, to hormone levels, to how we respond to medication. Our body clock is synchronised with the surrounding environment by exposure to daylight and the timing of meals. This synchrony is important for long-term health, and it is well known that disrupting your circadian rhythm by shift work or travel across time zones can be detrimental for health. Importantly, it is thought that eating at unusual times, as often occurrs during shift work and jet lag, is a major cause of body clock disruption. However, it has not previously been known exactly how the body clock senses and responds to meal timing, making it difficult to provide medical advice or interventions that might alleviate the problem.
Researchers at the MRC Laboratory of Molecular Biology (LMB) in Cambridge and the University of Manchester have now identified insulin as a primary signal that helps communicate the timing of meals to the cellular clocks across our body, and in doing so strengthen the circadian rhythm. The team's experiments in cultured cells, and replicated in mice, show that insulin, a hormone released when we eat, adjusts circadian rhythms in many different cells and tissues individually, by stimulating production of a protein called PERIOD, an essential cog within every cell's circadian clock.
Dr John O'Neill, a research leader at the MRC LMB who led the Cambridge research team, said: "At the heart of these cellular clocks is a complex set of molecules whose interaction provides precise 24-hour timing. What we have shown here is that the insulin, released when we eat, can act as a timing signal to cells throughout our body."
Working with Dr David Bechtold, a senior lecturer at the University of Manchester, the researchers found that when insulin was provided to mice at the 'wrong' biological time -- when the animals would normally be resting -- it disrupted normal circadian rhythms, causing less distinction between day and night.
Dr Bechtold said: "We already know that modern society poses many challenges to our health and wellbeing -- things that are viewed as commonplace, such as shift-work, sleep deprivation, and jet lag, disrupt our body clock. It is now becoming clear that circadian disruption is increasing the incidence and severity of many diseases, including cardiovascular disease and type 2 diabetes."
Dr Priya Crosby, a researcher at the MRC LMB and lead author on the study, highlighted: "Our data suggests that eating at the wrong times could have a major impact on our circadian rhythms. There is still work to do here, but paying particular attention to meal timing and light exposure is likely the best way to mitigate the adverse effects of shift-work. Even for those who work more traditional hours, being careful about when we eat is an important way to help maintain healthy body clocks, especially as we age."
https://www.sciencedaily.com/releases/2019/04/190425143607.htm