Like the depths of our oceans, the human mind has been charted only at its surface, leaving vast amounts of knowledge yet to be discovered. Among the issues yet to be explored is the effect of intermittent fasting (IF) as a possible intervention for dementia.
IF is defined as an eating pattern in which individuals switch between fasting and normal food intake on a regular schedule. Although the exact mechanism that drives IF outcomes has been a source of contention in the medical community, it has been shown to be an effective intervention against obesity, non-alcoholic fatty liver disease and chronic diseases such as diabetes and cancer. But what about dementia? Can IF play a role in the preservation of the human mind? Let’s dive in.
Due to the sheer magnitude of our oceans, we often take for granted the possible negative impacts of what we introduce into them. Similarly, the harsh reality of human overconsumption has not yet revealed its effect on the human mind. Or has it?
A recent study found that global cognition, verbal memory, language and executive functions improved in correlation with a decrease in body mass index (BMI). The pronounced correlation between the results and the age of patients also suggests improved outcomes with early intervention. Astonishingly, the study goes on to describe the correlation between specific categories of nutrients and their cognitive impact. It found that a decrease in carbohydrate intake was associated with improvement in verbal memory, executive function and subjective complaints. On the other hand, a decrease in fat intake was associated with improvements in verbal memory.
Alzheimer’s disease (AD) remains the leading cause of dementia among the elderly. Although not fully understood, IF has shown to have a possible neuroprotective effect leading to an increase in the neurogenesis levels in the hippocampus. This may provide protection against acute brain injuries such as stroke and neurodegenerative diseases. A study of 1,993 subjects of 60 years old and above revealed that Caloric Restriction (CR) can slow cognitive decline. In contrast, subjects with higher blood sugar and hyperlipidemia were found to be at higher risk for cognitive decline.
As we explore the ecosystem beneath the surface of the mind, we can witness the responses when consumption variables change. For example, gastric bypass surgery is a common procedure aimed at reducing a patient’s caloric intake. However, Roue-En-Y Gastric Bypass surgery leads to an improvement of cognitive functions and a significant reduction in the expression of amyloid beta precursor protein mRNA and protein in mononuclear cells, which has a role in preventing AD. There was a significant reduction in the expression of two other proteins involved in the formation and deposition of β-amyloid.
On a cellular level, the human body engages in a process called autophagy, meaning self (auto) eating (phagy). This cellular function breaks down and recycles cells that are damaged or mutated to provide nutrients to those that are not. Why is this important? The hallmark of AD is the buildup of β-amyloid that damages neuronal cells. CR and IF may have a role in inducing autophagy in protein-laden cells, clearing that buildup and leading to cognitive improvement. IF may provide a mode of cellular maintenance as well as cellular protection.
Brain-Derived Neurotrophic Factor (BDNF), a molecule involved in changes related to learning and memory, has been associated with 10-year risks for incident dementia in a large population-based sample. However, BDNF levels increase with physical activity and reduced caloric intake, leading to a potential therapeutic effect in decreasing dementia risk.
Thus, IF has been shown to have an effective role in the management and prevention of dementia. It improves cognitive functions and no adverse effects have been linked to it in reviewed studies.
It’s commonly said that what we most want to find is in the place we least want to look. Although the idea of exploring the bottom of the ocean induces a sense of anxiety and fear, it may provide the very answers we need to better understand our species. Similarly, future research in the area of CR and IF and their effects on dementia will surely bear these same fruits.
The author would like to acknowledge Keisa Mokenela, BSc.MD candidate at St. James School of Medicine, for his contributions to this post.