Over 6 million Americans are affected by Alzheimer’s disease (AD) according to recent estimates, and those numbers are predicted to increase with the aging population. Those with this debilitating disease struggle to deal with a range of symptoms which includes a variety of disruptions to their circadian rhythms such as changes to their sleep cycle, increasing moments of confusion, difficulty falling to sleep and staying asleep, and loss of lucid moments.
Findings from their mice studies suggest that it is possible to correct circadian disruptions that are connected to Alzheimer’s disease with a variation of time-restricted feeding that prioritizes limiting the eating time window without restricting the amount of food consumed. The authors report that animals fed on this time-restricted schedule displayed improvements in memory as well as reductions in the accumulation of amyloid proteins in their brains.
“For many years, we assumed that the circadian disruptions seen in people with Alzheimer’s are a result of neurodegeneration, but we’re now learning it may be the other way around — circadian disruption may be one of the main drivers of Alzheimer’s pathology,” says senior study author Paula Desplats, Ph.D., professor in the Department of Neurosciences at UC San Diego School of Medicine. “This makes circadian disruptions a promising target for new Alzheimer’s treatments, and our findings provide the proof-of-concept for an easy and accessible way to correct these disruptions.”
“Circadian disruptions in Alzheimer’s are the leading cause of nursing home placement,” Prof. Desplats explains. “Anything we can do to help patients restore their circadian rhythm will make a huge difference in how we manage Alzheimer’s in the clinic and how caregivers help patients manage the disease at home.”
Currently, there is no known cure for this horrible brain-wasting disease despite decades of research. In recent years, boosting the circadian clock has been emerging as a promising approach to improving brain health, and controlling the daily cycle of eating/fasting is one way to accomplish this. To test this theory the researchers used mouse models of Alzheimer’s disease that were only allowed to eat within a six-hour window, which in the human equivalent would be around 14 hours of fasting, and the results were compared to controls who were given free access to food at all hours.
Mice in the intervention group displayed stringer memory, were less hyperactive at night, followed a more regular sleep schedule, displayed fewer sleep disruptions, and performed better on a series of cognitive tests compared to the controls. Additionally, it was noted that the intervention animals also had improvements on molecular levels in multiple genes associated with AD, neuroinflammation expression was differently, and there were reductions in the accumulation of amyloid proteins in their brains, all of which are some of the most well-known features of Alzheimer’s disease.
According to the researchers, their findings demonstrated that the time-restricted feeding schedule helps to mitigate some of the behavioral symptoms associated with AD. As this intervention appeared to substantially change the pathology of the disease in mice, the researchers are optimistic that their findings will easily translate to human clinical research, with the added benefit of the intervention approach being based on lifestyle changes as opposed to relying on drugs that can have negative side effects.
“Time-restricted feeding is a strategy that people can easily and immediately integrate into their lives,” Prof. Desplats concludes. “If we can reproduce our results in humans, this approach could be a simple way to dramatically improve the lives of people living with Alzheimer’s and those who care for them.”
