A study has shown that it is possible to correct the body's biological clock in Alzheimer's patients with time-restricted diets, a type of intermittent fasting focused on limiting the daily eating window without limiting the amount of food consumed.

Nearly 80 per cent of people with Alzheimer's experience difficulty sleeping and worsening cognitive function at night, confusion in the evenings, and difficulty falling and staying asleep.

A new study from researchers at the University of California (UC) San Diego School of Medicine has shown in an experimental model that it is possible to correct the circadian disruptions seen in Alzheimer's disease.

In the study, published in Cell Metabolism, experimental models that were fed on a time-restricted schedule showed improvements in memory and reduced accumulation of amyloid proteins in the brain. The authors say the findings will likely result in a human clinical trial.

"For many years, we assumed that the circadian disruptions seen in people with Alzheimer’s are a result of neuro-degeneration, 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,” said senior study author Paula Desplats, a professor in the Department of Neurosciences at UC San Diego School of Medicine.

“Our findings provide the proof-of-concept for an easy and accessible way to correct these disruptions,” she added.

The researchers tested this strategy in an experimental model of Alzheimer’s disease, feeding the experimental model on a time-restricted schedule where they were only allowed to eat within a six-hour window each day. For humans, this would translate to about 14 hours of fasting each day.

Compared to the control experimental model who were provided food at all hours, the experimental model fed on the time-restricted schedule had better memory, were less hyperactive at night, followed a more regular sleep schedule and experienced fewer disruptions during sleep.

The test experimental model also performed better on cognitive assessments than the control experimental model, demonstrating that the time-restricted feeding schedule was able to help mitigate the behavioural symptoms of Alzheimer’s disease.

"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,” said Desplats.

The researchers also observed improvements in the experimental model on a molecular level. In an experimental model fed on a restricted schedule, the researchers found that multiple genes associated with Alzheimer’s and neuroinflammation were expressed differently.

They also found that the feeding schedule helped reduce the amount of amyloid protein that accumulated in the brain. Amyloid deposits are one of the most well-known features of Alzheimer’s disease.

“Time-restricted feeding is a strategy that people can easily and immediately integrate into their lives,” said Desplats.