Intermittent Fasting for Improved Brain Health

intermittent fasting and brain health
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What if there were a simple, easy way to improve your brain health? Intermittent fasting not only has the potential to make you smarter, happier, and healthier but could help you stay that way for longer, well into old age. We explore the science behind intermittent fasting for brain health.

Fasting, Brain Health, and Evolution

When humans were hunter-gatherers, food was sometimes plentiful, and sometimes scarce. Feast or famine was a way of life. In evolutionary terms, you’re still a hunter-gatherer because your body hasn’t had time to adapt to the constant availability of food modern life offers.

Humans who survived the feast or famine era, developed sharper brain function when they went hungry. They needed to be at the top of their game to hunt. 

Societies have slowly developed around steady sources of food. But before food became reliably available, people most likely ate one or two large meals per day. It’s likely their sleeping patterns were similar to our own. 

Hunter-gatherers would have eaten their meals during the day when it was easier for them to find food. They had no way to save and store leftovers, so there was no easy quick, easy breakfast available as soon as they rolled out of bed. Their natural eating pattern was probably similar to a 16:8 style fast.Modern life makes food available to you 24/7, but your mind has evolved to perform best when it cycles through fed and fasted states. Scientists caution against interpreting this as a reason to return to caveman-like living, but they do recognize your brain can perform better as a result of intermittent fasting.

How Fasting Changes Your Brain

An eating plan that stabilizes your blood sugar, reduces systemic inflammation, and removes free-radicals positively impacts your brain as well as your body. Intermittent fasting can do all that  effectively. Here’s how:

intermittent fasting for brain health

Brain Proteins

Intermittent fasting improves your brain health by increasing your production of the brain-derived  neurotrophic factor BDNF. This protein helps the neurons in your brain resist degeneration, disease, and dysfunction. For example, some studies show BDNF may help your neurons resist age-related brain diseases like dementia, and play a vital role in stroke rehabilitation.

BDNF preserves homeostasis in your brain by mediating the effects of fasting on mood, cognition, cardiovascular functioning, and peripheral metabolism. BDNF increases your insulin sensitivity and regulates your heart rate and other parasympathetic actions.

In short, BDNF helps you be smart, energetic, and happy, and entering into a fasted state will trigger it.


Autophagy is the process your body uses to break down and clear out damaged cells to make space for new ones. Short-term fasting causes a substantial increase in neuronal autophagy, which takes place in your brain. Dysfunctional autophagy is associated with age-related brain diseases, like Alzheimer’s, Dementia, Amyotrophic Lateral Sclerosis (ALS), Huntington’s, and Parkinson’s disease. We need more studies on humans, but early research shows intermittent fasting can prevent the early onset of these brain diseases and help improve cognition.


Ketosis is the process your brain uses when it turns to fat for energy if glucose is no longer available. It’s triggered by intermittent fasting, which removes glucose as a source of energy during the fasting window. This “metabolic switch” is related to your brain health for a variety of reasons. 

You can achieve ketosis by following a ketogenic eating plan, but that’s not sustainable long term. Intermittent fasting offers many of the same results and a few unique ones, and it’s a healthy lifestyle option, not a diet.


Neuroplasticity is your brain’s ability to create new neuronal networks, and metabolic switching enhances this process. During metabolic switching, your brain receives energy from glucose when you eat, and from fats when you fast. The resulting molecular and cellular adaptations enhance your brain’s resistance to injury, disease, and stress. 

Neuroplasticity as a result of intermittent fasting can enhance your cognitive function and improve your mood as new neurons form in your prefrontal cortex. It’s the process of hormesis, triggered by intermittent fasting, which reduces your inflammation and oxidative stress, and increases neuron growth to improve your memory, learning, and cognition.

How Intermittent Fasting Makes You Smarter

Studies in mice show the mice who fasted were more alert, learned more quickly, and showed improvements in their memory, as opposed to mice who were fed regular meals. The fasted mice experienced new neuron growth and an increase in brain connectivity. 

BDNF is increased when ketones increase, autophagy improves new cellular growth, and neuroplasticity increases connections in the prefrontal cortex.  

From an evolutionary standpoint, it makes sense that brain size and cognitive function would be preserved during times of fasting, even when the body loses weight and organs reduce in size in response to caloric restriction.

How Intermittent Fasting Can Make You Happier

What’s good for your brain is good for your emotions, and intermittent fasting may play a positive role here too. Scientists hypothesize that the effects of fasting on the neuroendocrine system include an antidepressant effect. Both human and animal studies show intermittent fasting can reduce your risk of depression and produce an antidepressant effect. Fasting may increase your sense of euphoria and reduce your stress, anxiety, and tension. This effect is thanks to the increased presence of BDNF, ketone production, and an increase in the availability of neurotransmitters and serotonin.

Intermittent fasting and aging

Fasting, Brain Health, and Aging

Intermittent fasting’s effects on your brain health are especially important as you age. As you age, you may see a significant decrease in the autophagy process, which can lead to age-related brain disease. 

Intermittent fasting maintains your brain health by changing the cellular and metabolic pathways that regulate human life-span. So, your neurons are protected from environmental and genetic factors that would otherwise trigger disease and deterioration. 

Scientists are still trying to understand how these processes work, but, early studies show fasting affects your brain health through insulin signaling pathways, antioxidant effects, proteins such as BDNF, and other neurotrophic factors. 

It’s never too late for a fasting protocol to have positive effects. A study of adults over the age of 60 demonstrated that intermittent fasting improves memory. As levels of insulin decreased while in the fasted state, memory increased. 

Could fasting help you live longer by keeping your brain functioning as you age? Some scientists think so and are studying the effects of intermittent fasting on human life-span. 

It makes perfect sense that intermittent fasting can boost your brain health and just as it can improve your overall health and wellness since the two are intimately connected. Intermittent fasting can help you live better now and slow down aging by improving your e cognition, mood, and memory.

Author's bio


Sara-Mai Conway

Sara-Mai is a writer who specializes in physical and mental health, nutrition, and fitness. She has 20 years of professional experience in the health and wellness industry and is a certified yoga instructor.