Time-restricted feeding, also known as intermittent fasting, involves limiting the energy consumed to specific times of the day and fasting the rest of the time. According to a recent study, time-restricted feeding enhanced cognition and decreased Alzheimer’s pathology in the brain in a mouse model.
Alzheimer’s disease, the most prevalent type of dementia, is a progressive and eventually fatal neurological disorder. Despite the massive research to find its precise underlying causes and treatment, its proper cure remains unknown.
Current treatments available can assist in relieving symptoms such as memory loss, sleep problems, and behavioral concerns. Donanemab, aducanumab, and lecanemab, three more recent monoclonal antibody medications that remove amyloid plaques (the hallmarks of Alzheimer’s), perform well in clinical trials. However, due to ongoing research, these are not yet generally accessible. Lifestyle changes are another strategy for alleviating Alzheimer’s symptoms.
According to a laboratory study, time-restricted feeding rectifies the circadian abnormalities caused by Alzheimer’s, enhances cognition, and lessens the buildup of amyloid, a protein linked to the development of dementia [1].
A recent mouse model study from the University of California San Diego School of Medicine published in Cell Metabolism revealed that intermittent fasting, or time-restricted feeding, may assist patients with Alzheimer’s [2].
What is Intermittent Fasting?
Intermittent fasting or time-restricted feeding entails whole or partial food abstinence. Methods include eating only during a specific time daily or fasting one or more days every week while eating regularly on the other days.
Although there is little study on intermittent fasting in humans, numerous studies are underway due to its supposed several health advantages.
Weight loss, a lower risk of type 2 diabetes, better heart health, a lower risk of some malignancies, and better brain function are all possible benefits.
Previous mice research has connected time-restricted feeding to gene modifications, longer life spans, and a lower risk of developing cancer [4]. According to the most recent study, time-restricted feeding in mice reversed the circadian abnormalities caused by Alzheimer’s disease.
Circadian disturbances and Alzheimer’s
Circadian disruptions, such as irregular sleep patterns and trouble falling or staying asleep, are common aspects of Alzheimer’s and frequently start before the disease has fully developed.
According to research, there is a bidirectional association between circadian abnormalities and the pathology of Alzheimer’s disease [5]. Circadian rhythm modifications cause protein buildup and other modifications linked to neurodegeneration. Additionally, dysfunctional circadian rhythms are a result of neurodegenerative alterations.
Alterations in activity patterns in models of Alzheimer’s
Transgenic mice designed to develop the pathology of Alzheimer’s and wild-type mice were both used by the researchers in the latest study.
The researchers randomly separated the mice into two groups, each with some transgenic and some wild-type mice. All the mice were accustomed to 12 hours of darkness and 12 hours of light.
The transgenic Alzheimer’s disease mice had disturbed sleep patterns and irregular activity rhythms, and they were considerably more active at night than the wild-type mice.
One group had access to food continuously, whereas the other only had it available for six hours each day during the 12-hour light period. Both groups consumed equal amounts of food despite the different food availability, and there were no apparent changes in body weight between them. The researchers assessed the mice’s cognitive function via the novel object recognition test (NOR) and eight-arm radial arm maze (RAM) methods. They also collected blood samples from the mice for investigation.
They euthanized the mice at the end of the experiment and examined their brains to determine changes in gene expression and the degree of amyloid buildup.
Benefits of time-restricted feeding
Time-restricted feeding reduced blood glucose levels in all mice and altered gene expression in Alzheimer’s mice, curtailing the expression of genes associated with neuroinflammation and regulating clock-controlled genes. The researchers investigated the effect of time-restricted feeding on behavior in Alzheimer’s disease mice after 3 months. They discovered that males and females had different impacts, with only females enhancing total sleep. Both sexes experienced enhanced sleep onset and decreased hyperactivity.
Compared to mice with unlimited food, the Alzheimer’s disease animals on time-restricted feeding showed considerably fewer amyloid plaques. According to the researchers, time-restricted eating may minimize amyloid accumulation while increasing the amyloid elimination rate.
Additionally, the mice receiving time-restricted feeding displayed enhanced cognitive and memory abilities. Before time-restricted eating, the Alzheimer’s disease mice scored lower than wild-type mice in the NOR and RAM tests. When given time-restricted feeding, they performed better on both tasks than Alzheimer’s disease mice who had unlimited food. The cognitive function of the Alzheimer’s disease mice on time-restricted feeding increased to nearly identical levels to those of the wild-type mice.
What’s next?
Even though the study involved mice, and results from studies on animals can be challenging to extrapolate to studies on humans, it offers a solid framework for considering how intermittent fasting may impact Alzheimer’s disease in people. Given the potential benefits of intermittent fasting for neuroprotection and metabolic health, it is logical to assume that there will be similar effects in people.
The study’s researchers believe that intermittent fasting could be a simple method to help patients with Alzheimer’s with their circadian issues, which is one of the primary reasons they require residential care. If researchers can replicate these findings in humans, this strategy could be a simple approach to drastically enhance the lives of patients with Alzheimer’s and their caregivers.
References
- Vetter, C., 2020. Circadian disruption: What do we actually mean?. European Journal of Neuroscience, 51(1), pp.531-550.
- Whittaker, D.S., Akhmetova, L., Carlin, D., Romero, H., Welsh, D.K., Colwell, C.S. and Desplats, P., 2023. Circadian modulation by time-restricted feeding rescues brain pathology and improves memory in mouse models of Alzheimer’s disease. Cell Metabolism
- Deota, S., Lin, T., Chaix, A., Williams, A., Le, H., Calligaro, H., Ramasamy, R., Huang, L. and Panda, S., 2023. Diurnal transcriptome landscape of a multi-tissue response to time-restricted feeding in mammals. Cell metabolism, 35(1), pp.150-165.
- Pan, X., Taylor, M.J., Cohen, E., Hanna, N. and Mota, S., 2020. Circadian clock, time-restricted feeding and reproduction. International journal of molecular sciences, 21(3), p.831.
- Li, P., Gao, L., Gaba, A., Yu, L., Cui, L., Fan, W., Lim, A.S., Bennett, D.A., Buchman, A.S. and Hu, K., 2020. Circadian disturbances in Alzheimer’s disease progression: a prospective observational cohort study of community-based older adults. The Lancet Healthy Longevity, 1(3), pp.e96-e105.
- Could time-restricted eating help manage Alzheimer’s symptoms? Medical News Daily. https://www.medicalnewstoday.com/articles/intermittent-fasting-time-restricted-eating-alzheimers-disease#Why-might-intermittent-fasting-cause-improvements. Published Online: 29th Aug, 2023, 7th Sep, 2023.
