Intermittent Fasting: Changing the tides of dementia

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.

The comments section is closed.

  • Manju Rai says:

    Along with diet and intermediate fasting, you should also do physical exercises as well. You can do jogging, Yoga and other things. Also, you can start with resistance bands if you want to start exercising at home. An alone diet can’t help you to maintain a healthy and balanced life.

  • Barry Flath says:

    Good general piece on the potential of a safe and simple approach to prevent a number of age related disorders. CR mimetics, autophagy /mitophagy inducers and senolytics for clearing damaged cells are all key areas of current research. IR and CR may be one way to activate all these processes.

  • Othman Farahneh says:

    I am currently researching the effect of intermittent fasting (IF) and caloric restriction (CR) on dementia and cognition. I can tell that the results are promising and in fact, many studies concluded that IF and/or CR has a positive impact on cognitive functions. Esplanade M RCT (2018) was 10 years long and had a large sample cohort (n=5145). Participants were randomly assigned to Intensive lifestyle intervention which consists of CR 1200–1800 kcal/day and ≥175 min/week physical activity and control diabetes support and education group, it was found that Intensive lifestyle intervention was associated with better cognitive outcomes and lower complaints about difficulties in decision-making and problem-solving ability. Also, a decrease in BMI through CR in obese participants with mild cognitive impairment was correlated with improvements in memory, executive function, global cognition, and language, [Horie’s RCT (2016)]. another study that studied the effect of CR on cognitive functions was Prehn RCT (2017), it was found that after 12 weeks, the CR group found to have a better memory performance, learning, delayed recall compared to the control group, in addition to a significant increase in gray matter density in bilateral Inferior frontal gyrus in the CR compared to the control group.

    In the literature, There are only limited studies discussing specifically the effect of IF on dementia in humans, however, some studies assessed other types of interventions that may mimic IF, such as decreasing the caloric intake without a complete fasting period, weight loss, DASH diet, Blood Pressure reduction, and exercise. These studies can indicate that lifestyle intervention might play important role in the management of dementia, especially because pharmacotherapy has a limited effect.

    Based on the above-mentioned RCTs and other RCTs in the literature that found a positive impact of IF in humans and laboratory animals, IF might have a positive impact on cognition and dementia, However, further research is still needed.

    Thank you

  • Catherine Oliver says:

    I don’t understand the conclusion here. Some of these studies appear to be about weight loss, not IF. And the studies related to IF contain qualifiers like “may”, “possible” and “potential.”
    So how can the conclusion be ” IF has been shown to have an effective role in the management and prevention of dementia.”?
    I’m aware that Healthy Debate is not a peer-reviewed publication, but I would like to know if
    there is some kind of review of articles before they’re posted in Healthy Debate, or can anyone just post whatever they want?

    • Marska99 says:

      This is labelled as an opinion piece. This is the author’s take. That’s it. It’s how this Helen person has made conclusions based on the presented evidence. You might come to a different conclusion, but it’s her piece.

      Learn the difference between opinion, reporting and peer-review before you make an ignorant comment like this. Jeez. Can’t believe this even warrants explaining.



      • Hah says:

        Remarkable you’re calling someone ignorant and citing Wikipedia.

      • Linda says:

        I.F. is often practiced in relation to a Keto diet. A Keto diet removes most carbohydrates(which convert to sugars) from the diet. Since it was discovered that a doctor in the U.S. reported false research data concerning the need for high amount of carbohydrates in our diet, which resulted in a North American food guide that called for a high number of servings of carbohydrates, the result was a population of overweight people. The suggestion that fats be limited and that fats are bad, also created many health issues. There has been research showing that it is necessary for our brains to have certain fats to function properly, hence, a higher rate of dementia and alzheimers.
        I would challenge doctors with a science background to take their critical thinking into the realm of understanding the chemistry and what is happening at that level, when I.F. is employed. It is a very old idea that if everyone lost weight our world would be healthier. Unhealthy people need help to become healthy and then they can loose weight. Unfortunatley, many healthcare providers spend too much time judging patients, instead of determining what is happening to cause them to gain weight. Medicine needs to start doing the job of science, not guessing. When we start doing more research and start thinking out of the pharmaceutical box, perhaps there could be a clearer understanding of disease states and a better treatment protocals that includes actually curing disease, not just doing symptomatic treatment that generally causes more issues. Most pharmaceutical drugs do not cure disease, but cover symptoms or change natural body processes. Doctors also need to have a mandatory ongoing education requirement to keep up with the science that is often times out there but not being reviewed, and be willing to learn from the experiences of their patients. We have developed an aging population that is unwell in later years and is plagued with prescription drug use as a fast, simple way to symptomatically treat patients and make them reliant on the healthcare industry.


Helen Senderovich


Helen Senderovich is an assistant professor at the University of Toronto, practicing palliative care and geriatrics at Baycrest, a clinician-teacher, researcher and an author of manuscripts and books.

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