The brain is an amazing and incredibly busy organ, working 24/7 to keep you alive and well. Though it weighs only about 3 pounds, it’s a mighty machine that regulates just about every aspect of your existence, from thought, emotion, senses, behavior and movements to hundreds of behind-the-scenes ‘automatic’ bodily processes like breathing, heart rate, body temperature, hormone balance and so much more. So, protecting its health – and helping it age as slowly as possible – becomes, well, a no-brainer.

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Fortunately, there are a number of ways you can help put the brakes on your brain aging process. One of my favorites is free, easy and enormously beneficial – I’m talking about intermittent fasting (IF), also known as ‘time-restricted eating’ or TRE.

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While you might think of IF as a weight-loss hack (note: the jury’s still out on how helpful it actually is for weight), its benefits go far beyond the scale – improving heart health, blood sugar control and reducing inflammation, blood pressure and even cancer risk. And yes, it does some impressive things for your brain as well. 

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Though the idea of fasting been around for thousands of years – even Hippocrates was a fan – more recently, scientists and neurologists have started to pay more attention to how taking regular breaks from eating can protect your brain and possibly even sharpen your cognitive powers. 

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So, how does IF help upgrade your brain’s health, for as long as possible? Let us count the ways fasting can make that happen:

1. It helps give your brain a deep clean.

When you fast – remember we’re talking hours, not days – your body switches on the process known as ‘autophagy,’ that is, the cleaning up and recycling system for your cells. The autophagy process clears out the worn-out cells, strips out the salvageable cellular parts and then recycles them to use for energy and to create new cells for your brain (and elsewhere). Fresh, healthy, newly-built brain cells? Yes, please – and keep ‘em coming.

2. It helps tame inflammation in your brain.

We now know that chronic inflammation is the gateway to a world of chronic ills. When it comes to the brain, inflammation is known to be major factor in cognitive decline and the development of neurological diseases like Alzheimer’s. So, what’s the work-around? Get that inflammation down with a bit of IF. Fasting has been shown to lower levels of inflammatory markers, helping to protect your brain in the long run.

3. It boosts brain-derived neurotrophic factor (BDNF).

When it comes to brain-derived neurotropic factor or BDNF, more is definitely better – and fasting boosts levels of BDNF, which supports learning, memory, mood and reduces risk of neurodegenerative disease. BDNF is a naturally occurring protein in the brain that helps keeps your billions of brain cells thriving and healthy. It helps grow new cells and cell pathways, while strengthening the brain and nerve cells you already have, protecting them from damage caused by stress. You could think of it as Miracle-Gro for your brain cells.

4. It powers up your brain’s energy factories.

Energy – we all need it, especially our brains. Turns out, IF improves the production and function of our mitochondria, the energy powerplants found in most of our cells. What does that mean for your brain? Well, it will likely work better, with more mental clarity and less brain fog. IF has also been shown to improve mitochondrial function by boosting the activity of the mitochondria themselves and by reducing free radical production, both which slow down brain aging and reduce the chances of developing neurodegenerative diseases like Alzheimer's, Parkinson's and Huntington's disease.

5. It switches your brain over to clean-burning fuel.

If you fast long enough, your body can start to make ketones —  a.k.a., the chemicals your liver produces from fat when glucose (your usual energy source) is in short supply. And, as luck would have it, your brain absolutely loves to run on ketones. They’re actually a more efficient fuel than glucose, and research indicates that they can help improve mental clarity and support brain health over time. Some studies even show ketones may help protect brain cells and reduce the risk of diseases like Alzheimer’s – and we’re certainly all for that.

6. It helps regulate your blood sugar and insulin levels.

By now, anyone much over the age of 25 knows that keeping blood sugar levels in check is essential to maintaining a healthy metabolism and for long term health in general. But, focusing on stabilizing blood sugar isn’t just good for your body below the neck — it’s a boon for your brain, and a crucial one at that. Fasting is especially helpful for improving insulin sensitivity, which reduces your risk of diabetes and brain conditions linked to insulin resistance, like Alzheimer’s.

7. It encourages the grown of new brain cells – score!

You may not realize it but, just as certain activities can kill brain cells (alcohol, I’m looking at you), the good news is that adults are capable of actually growing new brain cells. A lot of that growth happens in the hippocampus — the part of the brain that handles memory and learning. So, how to encourage brain cell growth? You guessed it – fasting has been shown to help make that happen.

8. It’s a drug-free mood-booster.

OK, so let’s talk mood. Many people frequently mention feeling more focused and upbeat when they fast, and studies have shown that IF is linked with enhancements in emotional well-being and a reduction in depression. So what factors are at play here? Think neurotransmitters and hormones. IF is thought to increase neurotransmitters such as serotonin and dopamine which contribute to a more balanced and less stressed feeling, while also helping to reduce fluctuations in hormones associated with mood.

9. It may help ward off Alzheimer’s and Parkinson’s.

Early animal studies suggest that fasting helps clear toxic proteins from the brain — like amyloid-beta — that are linked to Alzheimer’s and even slow progression in animal models of Alzheimer’s, Parkinson’s and Huntington’s diseases. In those studies, IF has been shown to increase the resistance of cells, tissues and organs to stress and common diseases associated with aging and sedentary, lifestyles. The hope is that in time, more studies will confirm similar effects in humans as well. 

Three steps to get into an IF groove.

If you’ve been toying with the idea of getting into IF, my advice is to start slow, to make your transition to this style of eating as easy as possible. Developing a bona fide IF regimen may take a little practice. Also keep in mind, it might not be right for everyone, so check with your doc first, particularly if you are pregnant, have a history of eating disorders, are on certain meds or have type 2 diabetes.  

That said, once you have the medical all clear, consider trying this three-phase approach:

STEP #1:

Start with – 12 on, 12 off – which means, start by eating all your meals within a 12-hour window (e.g., 8 AM–8 PM) and fast the remaining 12 hours. You’re probably already doing this (or close to it) without thinking about it, so it's an easy way to build awareness and establish a rhythm without major lifestyle changes. Do this for 3–7 days to get your body acclimated.

STEP #2:

Shift up to – 10 on, 14 off – up the ante a bit by fasting for 14 hours and eat within a 10-hour window (e.g., 9 AM–7 PM). You’re giving your body a little more fasting time without skipping meals entirely. This is where brain benefits – and a bit of fat-burning – really start to kick in. Do this for 7 days, or more if you need the extra time to feel comfortable with the extended fasting hours.

STEP #3:

Graduate to 8 on, 16 off – as in, fast for 16 hours and eat during an 8-hour window (e.g., 11 AM–7 PM). This is generally considered the “sweet spot” for many IF-ers — it’s sustainable long-term and supports fat burning, insulin sensitivity, cognitive clarity and fat loss. If 16 hours of fasting feels tough at first, just add fasting time in 15- or 30-minute increments over the course of a few days to your (step #2) 10 on/14 off program. 

Words of IF wisdom: do it like a pro.

If you’re a big snacker or an all-day grazer, IF may take a little more effort. If you do fall into the snacker/grazer camp, keep the following tips in mind:

1. Drink up: As in, think hydration, and lean into drinking water, black coffee, or herbal tea during fasting hours. Adding a pinch of sea salt to your water can help with electrolyte balance.

2. Keep your brain busy: If you are a hard-core breakfast-every-day-at-7 am without fail kind of person, starting your day without breakfast may feel a bit weird at first. To get over the hump, plan tasks or movement to distract yourself for the first few waking hours until your eating window begins.

3. Break your fast with quality stuff: No sugar-spiking flapjacks with maple syrup, thanks. Instead, start with protein, healthy fats, and fiber to keep your blood sugar stable, avoiding those sugar crashes. Think eggs + avocado, salmon + greens, or a protein smoothie. Make those meals count nutritionally.

4. Make sleep a priority: Fasting is harder when you’re under-slept. Aim for 7–9 hours of quality rest to support hormones like leptin and ghrelin which help control hunger.

5. Don’t play games with your eating window: In other words, avoid “famine to feast” syndrome, going on a binge eating rampage when your eating window opens. Focus on nourishing meals, not reward-style eating.