Autophagy | Calorie restriction | Coffee | Decaf | Matcha | Reishi | Chaga | Ginger-Lemon | Drinks to avoid | References
In this guide – learn what you can drink while intermittent fasting, and as importantly, what to avoid, including popular drinks and common mistakes that can break your fast.
What Can You Drink While Fasting?
In our last article, we talked about the health benefits of intermittent fasting. As we discussed, even a short 16/8 fasting regime can promote longevity and protect against various age-related diseases. As a neuroscientist who studies age-related diseases such as Parkinson’s and dementia, these findings are very intriguing.
But let’s say you just started your fasting journey or want to try one of the many different intermittent fasting schedules. You may be wondering about the exact logistics. Can you drink water while fasting? What about beverages aside from water? Is it ok to drink coffee while fasting? How about green tea? What about amino acids and pre-workout drinks? Apple-cider-vinegar? MCT Oils? How about putting a bit of salt and electrolytes in your water? Will they break your fast? Clearly, there are a lot of important questions around what you can drink while fasting that require quite a bit of research.
Delicious, near zero-calorie beverages to drink while fasting
In this article, we will go over drinks you can safely consume without breaking your fast. Even more, we’ll review a few ingredients that might even boost the longevity-promoting mechanisms of intermittent fasting and caloric restriction.
Also, we’ll focus on ingredients that won’t kick you out of ketosis and work well with most longevity lifestyles such as intermittent fasting while following a keto diet. So, you will be benefiting more from your fast. On the flip side, we’ll also talk about the potential side effects of some popular fasting drinks and common mistakes you should avoid while fasting.
To make this practical, we’ll focus more on common ingredients you can easily find in your local store or buy on Amazon, rather than exotic foods or anti-aging supplements, which we’ll cover in future posts.
I believe fasting drinks have an important place in many fasting protocols. They can help make fasting easier, enjoyable, and quite possibly, more effective. For many people, drinking while intermittent fasting can make this lifestyle much more sustainable. Having a few options you enjoy can help you stick with the plan.
I hope this information will help you get the most out of your fast and support your anti-aging and longevity goals.
What happens to your body when fasting?
In case you haven’t read our last article or if you wonder whether or not you should even fast, here’s a brief review.
Spoiler alert: I am about to share some incredible science. Expect to be inspired, and most likely, amazed at how intelligent your body is.
So, what exactly happens to our bodies when we fast?
- With fasting (and caloric restriction), you reduce the signaling pathways that are triggered by eating
- When the signaling pathways are reduced, your body then activates a protective mechanism for cell survival called autophagy that eliminates damaged cells, and at the same time, provides cells with essential nutrients[1].
- This is life’s intelligence in action. It makes sure we can survive in times when the food supply is scarce.
- To this date, autophagy is one of the most well studied anti-aging mechanisms. Based on the data, autophagy is strongly connected to an extension in both lifespan and healthspan[2].
Autophagy is the body’s natural way of clearing dead cells and toxic molecules. Essentially, it is the human body’s waste removal system at the cellular level[3]. This is a crucial longevity pathway shown in many studies to protect health and enhance lifespan.
Interestingly, autophagy has been found to decrease with age which is associated with accelerated aging[4]. In fact, in many age-related neurodegenerative diseases such as Parkinson’s and Alzheimer’s, we can see indicators of decreased autophagy such as aberrant protein accumulation[5].
On the flip side, stimulating autophagy has demonstrated impressive anti-aging effects[6]. For this reason, activating autophagy by fasting or in other ways is a potential way to prevent and protect against age-related diseases, and extend lifespan.
Feeling inspired yet?
How do fasting drinks work?
Clearly, we have plenty of evidence on the anti-aging potential of intermittent fasting. Realistically, however, the autophagy enhancement properties of intermittent fasting typically take time to show benefits, especially with short fasting window plans such as 16/8. Even more, fasting may not always be the easiest choice for everyone. Drinking nothing but water for 16 hours every day may not be something many people find appealing.
The good news here is that you don’t have to drink just plain water while intermittent fasting. In fact, you can implement other drinks and beverages that may even help to stimulate autophagy and other longevity pathways.
Now, in case you wonder how exactly this is possible, here’s some more anti-aging epigenetics science in action. The short answer, it is possible to drink more than water while fasting due to compounds known as caloric restriction mimetics[7].
Calorie restriction mimetics: can you have your cake and eat it too?
As their name suggests, caloric restriction mimetics are compounds that mimic some of the effects of caloric restriction and fasting. Once we consume them, the body responds by activating similar mechanisms and longevity pathways, like autophagy, in the same way as fasting and calorie restriction.
So, not only do these compounds not break a fast, but they may also augment its benefits.
The premise here, as one study nicely said, is that calorie restriction was shown to prolong the lifespan, but it is a very difficult thing to do. Eating compounds that reproduce the effect of calorie restriction without the need to actually restrict your calories, is much more sustainable[8]. In other words, you can have your cake and eat it too (no puns!)
Beverages you can drink during your fasting for autophagy
Now, powering your drinks with calorie restriction mimetics while fasting is more than just a theoretical idea. In fact, there’s solid evidence suggesting that these ingredients can take some of the potential benefits of fasting to the next level. Even better, these drinks can make the entire process more enjoyable.
So, without further ado, let’s get down to business, starting with my own personal favorite, black unsweetened coffee.
Can you drink coffee while fasting?
My favorite morning drink might be a bit cliche, I know. But based on the evidence, that one cup of coffee in the morning has such great potential for boosting the health-promoting actions of fasting, we simply can’t ignore it.
And that’s before we consider that coffee can really help you feel better during the fast. So, if you love coffee, and it agrees with you (more on that later), it’s a great evidence-based option you can drink while fasting.
In fact, multiple studies have shown that several compounds naturally found in coffee, especially caffeine and polyphenols, can activate anti-aging and longevity pathways[9,10].
Starbucks caffe latte or similar beverages, however, won’t work here. For best results, aim for unsweetened, black coffee.
Regular coffee (with caffeine) for fasting
Now, if you are like me, and prefer your cup of java with a good amount of caffeine, there may be benefits that seem related to caffeine. On the other hand, there are some caveats and known side effects of caffeine you should be aware of.
The good
At the cellular level, animal and human studies have shown that coffee can influence various longevity pathways such as mTOR and AMPK, which stimulate autophagy[11,12].
Additionally, caffeine is well known for its ability to enhance mood, alertness, reaction time, and attention. All of these can completely amplify your fasting experience. Something to consider, though, if you want to relax and rest during your fast, as the caffeine can make it difficult to chill.
The less good
Have you ever had too much coffee and felt wired, jittery, nervous, or even anxious? Now imagine what may happen if you drink too much coffee on an empty stomach while fasting.
Welcome to the dark side of caffeine. And you are definitely not alone here. As most coffee drinkers eventually discover, too much caffeine can cause some scary side effects like heart palpitations, nervousness, anxiety, and sleep issues. Coffee is such a common drink, we sometimes tend to forget that after all, caffeine is an extremely powerful stimulant.
Now, while some people who are extremely sensitive to caffeine should probably avoid caffeinated beverages altogether, it looks like for most people, there’s a sweet spot. To give you an idea, some studies that tested the effect of various amounts of caffeine, have found that 250mg of caffeine improved mood and performance, whereas a dose of 500mg led to nervousness, anxiety, irritability, palpitations, and even dizziness[13]. The only way to know where your threshold is with caffeine is to experiment. If two cups leave you feeling jittery, cut back to just one.
Decaf coffee can still help with fasting
Interestingly, both caffeinated and decaffeinated coffee have been shown to decrease mTOR levels in animal studies, suggesting that caffeine is not the only component of coffee that can stimulate autophagy[14,15].
In fact, the polyphenols in coffee have been shown to activate autophagy and display antioxidant and anti-inflammatory properties[16]. This is great news if you prefer to avoid or limit caffeine. You may still benefit if you drink decaf coffee while fasting.
Final thoughts about drinking coffee during fasting
As we can learn from these studies (along with the tons of anecdotal evidence from coffee drinkers), coffee can be a great drink option while intermittent fasting. Both regular coffee and decaf coffee can help enhance beneficial longevity pathways.
But what if you are not a coffee fan? Or, what if coffee doesn’t seem to agree with you? Clearly, coffee isn’t for everyone. For some people, coffee can cause sleep issues[17], stress, and anxiety[18]. Other people may experience gastrointestinal issues such as upset stomach, acid reflux and heartburn.
Luckily, mother nature’s anti-aging store is not limited to just coffee. Many other natural ingredients have been shown to support autophagy and other longevity pathways as well. We’ll cover these next.
The Anti-aging superpowers of matcha
You may have heard of matcha as a healthy substitute for coffee. Matcha has enough caffeine to give you a noticeable boost, yet, with a much gentler sustained release of energy compared to coffee. The more subtle energy boost is likely due to the other components in matcha. For people that wish to reduce their coffee intake, matcha is a great option.
What is less known about matcha, however, is that it components have been extensively studied for their remarkable anti-aging benefits.
And if that isn’t good enough, preparing and drinking matcha can be quite a culinary experience. With the vibrant green color, the grassy flavor, and the smooth texture, you can turn your fasting window into an adventure.
Before we dive deeper into some really exciting science, for those who aren’t familiar with matcha and how it is connected to longevity, here’s a quick summary:
What is matcha?
- Matcha is a type of traditional powdered green tea.
- It is grown in the shade which stresses the plant. As a defense mechanism, the plant then produces high levels of several longevity-promoting constituents, such as l-theanine, caffeine, chlorophyll, and a powerful calorie restriction mimetic molecule called epigallocatechin gallate (ECGC).
- When you drink matcha, your body is getting all these nutrients which can activate multiple longevity pathways including autophagy.
Matcha vs. regular green tea
- Unlike green tea which you infuse in hot water, with matcha, you drink the whole leaf.
- This means you consume more nutrients in their natural ratios.
- To give you an idea, one study that compared matcha to regular green tea found that the concentration of EGCG from matcha was 137 times greater[19].
Drinking matcha while intermittent fasting
Typical serving size of 2 grams of matcha has less than 10 calories and will not break your fast. In addition to caffeine, matcha is an excellent source of several powerful nutrients known for their anti-aging effects:
Epigallocatechin-3-gallate (EGCG)
This famous polyphenol is believed to be responsible for many of the health benefits associated with the consumption of green tea[20]. In terms of longevity, EGCG has been shown to promote autophagy by suppressing mTOR[21], and while this is definitely great, it can do much more for your health!
EGCG was also shown to positively influence gene expression. This means it can turn off “bad” genes that are linked to disease and turn on protective genes that can promote health and longevity[22]. This ability is known in the literature as epigenetic modification, which represents a very exciting area in longevity and anti-aging research. The premise here is that unlike our genetics which we can’t change, we can control which genes are on or off. We can do this with lifestyle choices such as diet, exercise, sleep, and other habits. Based on the research, consuming enough EGCG can help too.
L-theanine
This amino acid is known to promote alpha brain waves, which improves alertness and focus, but at the same time, relaxes the mind without inducing drowsiness[23]. This state is often associated with meditation, increased creativity, or being in the flow.
Furthermore, other data has suggested that theanine may work in synergy with caffeine to improve cognitive performance and mood[24]. For this reason, many people like to add theanine to their coffee to help “smooth” out the caffeine spikes. With matcha, you are getting both caffeine and theanine in their natural ratios found in the whole leaf. Mother nature’s chemistry is at your fingertips.
Final thoughts on drinking matcha while fasting
Hands down, the data on the longevity-health potential of matcha is quite impressive, which leaves many other great options behind. Drinking matcha while fasting can help:
- Promote multiple longevity pathways
- Support performance and well-being during the fast
- Eliminate coffee jitters
- Introduce new flavors and textures to your routine
The matcha you want to drink when you fast is very different from your local Starbucks matcha latte, though. Many matcha beverages you often see in restaurants are loaded with calories and sugars that can easily break your fast. Similarly to coffee, it is best to have your matcha with just water. When needed, you can add zero-calorie natural sweeteners such as stevia or monk fruit.
Sweeteners may be optional if you go with the high-end ceremonial grade of matcha, as these tend to have a mild sweet flavor on their own. The cheaper Culinary grade (often called premium or latte grade) is usually more bitter and is more suitable for smoothies or recipes.
Which matcha to buy for fasting?
Now, as I briefly mentioned, matcha is very popular and there are plenty of different options and grades of matcha you can buy. So, if you are new to matcha, expect a bit of a learning curve since both the matcha source and the way you make it can change your experience.
In fact, our LongevIQ research team has been studying matcha for a long time, including testing many different sources. Long story short, we experienced some drastic variations between different sources of matcha. In some cases, our testers even wondered whether the matcha they had was just standard-powered green tea! Clearly, the source of matcha matters.
Hopefully, we can share some of the findings soon. Make sure to subscribe and get our guide to choosing the best type of matcha to promote longevity when it is ready.
One more thing. If you follow Dr. David Sinclair, a Harvard professor of anti-aging (that is well known for his work on resveratrol and NMN), matcha seems to be his favorite drink while fasting. See his Instagram post on this topic. On that note, thank you David for inspiring us all to live a long and healthy life.
Reishi, the mushroom of immortality
Known as the mushroom of immortality, reishi (lingzhi, Ganoderma lucidum) has a long history of traditional use for promoting health and longevity in Asia. In Chinese medicine, reishi is viewed as an “herb of spiritual potency” with diverse medicinal properties to help increase vigor and vitality, and prolong lifespan[25,26].
Emerging research is catching up with this ancient knowledge, although it may take some time. No less than 400 bioactive compounds have been identified in reishi including triterpenoids, polysaccharides, nucleotides, plant sterols, fatty acids, and peptides. Even more intriguing is the fact that some of these naturally occurring compounds can only be found in reishi.
So, while reishi has demonstrated promising anti-aging and life extension benefits, we definitely need more studies to understand its full potential. There’s enough evidence, however, to suggest that reishi can activate several longevity pathways, which makes reishi a great option as a drink while intermittent fasting:
- Reishi has been shown to induce autophagy through the inhibition of the mTOR pathway[27]
- Certain polysaccharides and triterpenoids in reishi are able to upregulate the longevity genes FOXO4 and SIRT1[28] and activate the AMPK pathway[29].
- Reishi has also been shown to help with inflammation and oxidative stress, boost immune system function and protect the brain[30,31].
The best type of reishi to drink while fasting
Despite what you may expect, the fact that a natural ingredient is popular, doesn’t always mean you can easily find good sources of it. We have clearly seen this with matcha. What our team has discovered in the case of reishi, however, seems to take this challenge even further.
Depending on the extraction method and part of the mushroom used (fruit body, spores, and mycelium), you may get different benefits due to the different compounds in each part. And as if figuring this out is not complex enough, we haven’t even gotten to explore the impact of the environment and growing conditions or the type of reishi on its health benefits.
With all the variety and options on the market, it is best to buy reishi from a trusted source who specializes in medicinal mushrooms, that can share more data on the final product.
Some of the things to look for include:
- Lab analysis that shows the percentages of the active ingredients such as beta-glucan.
- The part of the mushroom used. Many reishi extracts only contain the mycelium, which is the root system of the mushroom. While we don’t have enough data to know for sure which part is best for longevity, some evidence suggests it may be the fruiting body[32].
- Watch out for fillers. Many medicinal mushroom products contain a significant amount of the medium the mushrooms are grown on (oats, rice, or other grains). Clearly, this doesn’t add any benefits, especially not when you fast. Ideally, aim for extracts that have had these removed.
A typical serving size is about 1 gram, although you may need more or less according to the extract potency. Simply mix the reishi with hot water and add monk fruit or stevia to sweeten. Notice that reishi brings a distinct earthy flavor to the beverage, and some extracts are very bitter. So, you have to experiment with different products as the flavor may vary. You can also mix reishi into your morning coffee for an added boost.
Does chaga break a fast?
Clearly, the evidence on reishi’s anti-aging activity is very intriguing. But what can you do if you simply can’t tolerate its flavor? Luckily, reishi is not the only medicinal mushroom that has shown longevity-promoting potential. Chaga (Inonotus obliquus) is another popular mushroom to consider that also comes with some really exciting evidence.
Here’s a quick summary of the research on the anti-aging potential of chaga:
- Induces autophagy by activating AMPK and inhibiting the mTOR pathways[33].
- Reduces oxidative stress and DNA damage[34].
- Helps with lipid metabolism, cardiac function, inflammation[35], and fatigue[36].
Now, similarly to reishi, we need to learn more about chaga’s anti-aging activity. Based on what we know at this point, however, we can say that drinking chaga while fasting is not likely to break your fast, and it may even help promote autophagy and other longevity pathways.
Flavor-wise, chaga brings a strong smooth earthy flavor that may resemble coffee. A typical serving size is around 1 gram. Mix it with hot water, add a bit of monk fruit or stevia, and enjoy! You can drink chaga on its own, with reishi, coffee, or combine all three together.
Drinking ginger lemon water and other herbal teas while fasting
Variety is the spice of life, but we are creatures of habit. Coffee and matcha are great options to drink while fasting, but they can only get you so far. For those times where your taste buds become bored, introducing something new can make a big difference.
For this purpose, unsweetened herbal teas are usually a really good option. (Watch out for fruit-based teas, however, as they may contain too much sugar).
Ginger – lemon water is a great example of a fasting drink that can open the door to some very interesting variations. You can make a hot tea with ginger and lemon or mix it with cold water instead. If you like fizzy drinks, you can mix these with sparkling water. While most people know ginger as a natural remedy for nausea or inflammation, the active compounds in ginger have been shown to promote autophagy and protect against oxidative stress[37,38].
Fizzy ginger-lemon tonic drink for fasting
Ingredients
- ½ lemon Drinking water with a few drops of lemon in the morning is a known ayurvedic practice to promote healthy digestion and detoxification.
- 1 inch fresh raw ginger root The active compounds in ginger have been shown to promote autophagy and protect against oxidative stress and inflammation, which play a role in many degenerative and age-related diseases.
- 500 ml carbonated water May help with hunger pangs in some cases.
- stevia or monk fruit (to taste) Natural sweeteners that do not impact blood sugar levels.
Instructions
- Peel the ginger root and run through a juicer
- Squeeze the juice of ½ organic lemon
- Add to the carbonated water and mix gently
- Add stevia or monk fruit to taste
- Enjoy!
What breaking your fast actually means
As you can see, there are plenty of options drinks you can enjoy while intermittent fasting. And based on the data, we can say that not only will these options not break your fast, but they are also likely to augment it.
But what exactly do we mean when we say “break the fast”? With so many different types of fasting schedules and intermittent fasting plans, what may be perfect for one plan may not be the best fit for another.
So, it’s important to consider your objectives. What are your goals? What are you trying to optimize for?
For example, are you interested in overall health, longevity, or anti-aging? Perhaps you are hoping fasting will help with weight loss or weight management. Maybe you are familiar with Dr. Jason Fung’s work and hope fasting will promote better metabolic health and insulin sensitivity. Perhaps you want to give your digestive system a rest and improve your gut health. The list of reasons why you might want to try fasting goes on and on.
Knowing your goals will help you choose the ideal plan or fasting window and avoid making mistakes that can “break your fast” which many people are unaware of.
Popular drinks and habits that break your fast
Getting out of ketosis
When you limit your food supply, especially sugar, your body eventually gets into a state of ketosis. This is when the body starts to produce ketones that act as an alternative fuel source to sugar. Ketosis is one of the major triggers of fasting mechanisms. But let’s say you just had a small beverage with just a few grams of sugars. Did this drink kick you out of ketosis? Did you just break your fast?
While everyone is different, even just a few grams of sugar may be enough to signal your body that “food is here”. This can break your fast.
Coconut water is a great example. It’s refreshing and a good source of several essential electrolytes, but it is still high enough in sugar to kick you out of ketosis. Similarly, many electrolyte drinks that provide your body with salt and trace minerals that can help with hydration, also have sugar in them. Generally speaking, keto electrolyte drinks are usually a better option to consider while fasting. Just read the label for the sugar content and make sure it says, “sugar free” and 0 grams of carbohydrates.
Staying in ketosis but consuming too many calories
The idea with most fasting plans is to reduce the signaling pathways triggered by food to activate various longevity pathways. The number of calories you consume during the fast is therefore very important, even if you stay in ketosis by consuming only fats.
Bulletproof coffee is a perfect example. Adding butter and other fats to your coffee may give you more energy and will not kick you out of ketosis. But with all these calories, your body may stop autophagy and other longevity pathways. And this is despite the fact that plain coffee is known to stimulate autophagy. There are just too many calories in this high fat coffee.
Another example is matcha latte drinks. While matcha is high in powerful anti-aging compounds shown to promote longevity mechanisms, many matcha beverages usually contain some sort of a creamer with dairy or almond milk. The addition of extra calories to the matcha may trigger similar pathways to eating a meal and halts the autophagy.
Activating mTOR
Now, let’s say your fasting drink has no sugar and is super low in calories. Clearly, that won’t kick you out of ketosis. Right? But what about autophagy and other longevity pathways?
Hands down, one of the most effective ways to shut down autophagy is to activate mTOR and protein synthesis, and according to research, that’s exactly what amino acids such as leucine, BCAA, and others can do[39]. You may recognize these from your pre or post workout drinks, and indeed, these have been shown to help with recovery after resistance training.
For those who aren’t familiar with mTOR, here’s a quick summary:
- mTOR is a protein that plays a key in cell growth and proliferation.
- When it is activated, it promotes anabolic cellular activity.
- While mTOR is a powerful pathway we need for growth and repair, it has also been shown to inhibit autophagy[40].
So, your favorite drink which may only have 5 calories with no carbs, can actually inhibit autophagy.
Another common example that many people love to consume during fasting is bone broth. Despite having very few calories, it is still high in the amino acid glycine, which can also stimulate mTOR[41].
Now, an important note here. Both autophagy and mTOR are essential for a long and healthy life. Many longevity researchers tend to focus on autophagy, but it is only part of the aging story.
The goal is not to inhibit mTOR indefinitely. Rather, we look for a cyclic fasting-eating pattern where you:
- Fast to promote autophagy and other longevity pathways to clear damaged tissues
- Refeed and activate mTOR to support building new tissue. This is important especially since loss of lean muscle mass and frailty are common concerns with aging. mTOR is definitely not the bad guy here.
Junk in fasting drinks
If you consider fasting as a tool to optimize longevity, health, and wellness, you may find this section obvious at first. But sometimes, we have to read the small print. When you take a closer look at the label of many popular drinks that appear healthy, you may find that they contain unhealthy ingredients.
Diet soda is a known junky zero-calorie drink. Your favorite fizzy drink may taste great and have zero calories, but under the hood, it contains artificial sweeteners such as aspartame or sucralose that are known to cause health issues.
Even all-natural flavored carbonated drinks often marketed as healthy tonics may not be as healthy as you think. Turns out, the devil is in the details. As a part of their flavoring, many of these drinks still contain some questionable ingredients. One common culprit is erythritol. This naturally occurring sugar alcohol doesn’t impact your blood sugar but is known to cause GI side effects.
Sometimes even knowing the benefits of intermittent fasting doesn’t make it any easier for some people, myself included. I’m much keener to participate in calorie restriction than to fully fast. That being said, my favorite way to commit to a full fast is to use tea.
In particular, I enjoy green tea with ginger. Green tea has great benefits in itself, a little caffeine to keep up the energy (but not too much, sometimes coffee on an empty stomach gives me the jitters), and the ginger can help in settling your stomach along with many other wonderful health benefits (such as anti-inflammatory properties). Ginger is a little spicy which keeps the taste buds distracted too. Bonus: both green tea and ginger help induce autophagy.
When fasting, black coffee and green tea are my go-to drinks if it’s before about 1 or 2pm. Other possibilities: turmeric tea and diluted apple cider vinegar. Both do technically have a few calories, but not really enough to break a fast. Both also contain a variety of beneficial compounds and offer an interesting flavor, which can be quite enjoyable while fasting. There are also some other herbal teas that I enjoy during a fast that have almost no calories. I’ll be flooded with a feeling of well-being as my body absorbs the antioxidants and other goodness present in the plants. Slowly sipping these is also a great opportunity for mindfulness during a fast.
I agree with the Coffee, Tea, and water.
I like to put fizzy C powder with bioflavonoids (Biofizz) into water to add some taste and fizz.