As we’re in the middle of the holy month of Ramadhan, I can’t help but wonder was there a deeper, scientific reason behind fasting. Perhaps a reason that could not be explained at the time. Whether you are Muslim or not, the benefits of intermittent fasting are evident through new and ongoing research. Some of the most renowned doctors promote fasting, all with a slightly different lens based on their area of interest. For example, Dr Ethan Weiss discusses the advantages to cardiological health and weight loss. Dr Rahul Jandial discusses the benefits in terms of increasing your brain’s natural growth factors and improving cognition. Dr Jason Fung is the world leading expert on intermittent fasting and low-carb diets, he discusses a broad range of advantages to this practice from regulating hormone levels to cellular repair. So, we know there are so many benefits – but does fasting impact dementia onset? And if so… how?
Typically, it is believed that we need to eat in order to maintain our function. Dr Jason Fung denies this claim, by stating that the brain is a vital organ, and brain power will be preserved beyond everything else and may even be exceeded in a fasting state. Think about Christmas day – after you feast on that huge meal, do you really feel mentally sharp? Or do you feel a little tired and dull? Even in the animal world, we’ve all seen images of a lion experiencing that post-prandial laziness after the maddest hunt.
But does fasting actually improve mental abilities? Studies have shown that intermittent fasting’s impact on glucose metabolism can have benefits in terms of neuronal resistance. Certain ketones that are expressed only when a person is fasting can stimulate the production on BDNF – brain derived neurotrophic factor, a brain derived hormone which is a key factor in increasing brain power.
Fasting does other things to – such as decreasing your glucose and regulating your insulin. Thus, in turn producing counter-regulatory hormones, and stimulating your sympathetic nervous system. This will result in more noradrenaline, which will make you more focused and better able to concentrate. This optimises a lot of things in terms of neuroplasticity, neurogenesis and neuron resilience. In order to see some of these benefits – the fasting period needs to be long enough to undergo the metabolic switch from glucose to ketones, typically this is around 14/16 hours.
There are additional processes that occur during fasting – known as autophagy and mitophagy. Autophagy is the process of intracellular recycling where your body breaks down old subcellular parts. Then, when you eat again – you are able to successfully rebuild these proteins. This is a process of regeneration and rejuvenation. When this is applied to the mitochondria – this is known as mitophagy. It is the mitophagy that could be playing a role in increasing the available energy to the brain which is the key factor in diseases such as dementia.
There are lots of studies out there that show that fasting can actually increase the resistance of neurons against damage. And there are other studies that suggest that you can cleanse your brain of some of the harmful proteins that are accumulating in AD. Alternate daily fasting has been shown to increase heat shock protein 70, and this helps to clear tau and amyloid protein which are toxic to the brain and accumulate in AD.
The great scholars and philosophers of the ancient Greek era all fasted to clarify their thoughts and improve their perspective abilities. Fasting is an important practice in Buddhism and Hinduism alike. Allowing your body an extending period without consumption could provide internal cleansing and rejuvenation – is it worth a try?
Thanks for listening, Hannah!
Hannah Hussain  is a PhD Student in Health Economics at The University of Sheffield. As a proud third generation migrant and British-Asian, her career path has been linear and ever evolving, originally qualifying as a Pharmacist in Nottingham, then Health Economics in Birmingham. Her studies have opened a world into Psychology, Mental Health and other areas of health, and with that and personal influences she found her passion for dementia.