Autophagy is a big trend in the health and longevity field and for good reason. Researchers are keenly interested in this process, as it actively contributes to the prevention and slowing of chronic diseases such as Alzheimer’s, cancer, and autoimmune disorders. It is a natural system in your body that fights aging and diseases.
Do you know that cellular garbage is constantly produced in your body? Every day, damaged tissue, misfolded proteins, and dead organelles build up inside your cells. When this metabolic waste builds up, it results in aging, chronic fatigue, brain fog, and autoimmune dysfunction. Your body already has a recycling system to deal with this, known as autophagy.
However, just knowing about the benefits of it does not mean that people also know how to activate it. The key to safe autophagy is determining exactly how to do it.
What is Autophagy?
The word comes from the Greek for “self-eating.” It is just as the name suggests. Autophagy is your body’s process of reusing old and damaged cell parts. It rejuvenates these deceased parts to form new healthy cells.
In the last 2 decades, researchers have learned that autophagy could also play a significant part in preventing and fighting diseases, such as Crohn’s disease, heart diseases, kidney diseases, liver diseases, and cancer.
That’s the reason why learning how to achieve autophagy is a justifiable health concern.
When Does Autophagy Begin?
Autophagy does not occur as soon as you stop eating. First, your body uses the stored sugar (glycogen). It normally occurs when the body has very low levels of liver glycogen. This begins about the 14th to 16th hour for the average human on a regular diet.
A study demonstrates that after 16–24 hours of fasting, autophagy starts to ramp up considerably, and it peaks at 48 hours. Some autophagy activity starts as early as 12–14 hours into a fast, which is why intermittent fasting can provide some benefits even with shorter fasting windows.
During autophagy, immune system benefits are more pronounced, including the recycling of old immune cells and the generation of new cells.
Is 16-hour fasting enough for autophagy?
The short answer to this question is: Yes, but for the following reasons.
Intermittent fasting, such as the popular 16:8 approach, has been shown to activate early autophagy processes if followed regularly. But a 16-hour fast gets you at the entry-level of autophagy, not at its maximum effect.
So, if you only do a standard 16:8 intermittent fasting protocol, you will get excellent benefits like improved insulin sensitivity and weight loss. However, if you want to engage in true deep fasting, you will have to extend your fasting period slightly.
Here, the consistency point matters more than most people realize. A 16-hour fast done regularly, 5-6 days per week, can accumulate maximum benefits of autophagy over time.
An occasional 24-hour fast does more in the single event but does nothing for the other six days.
So, yes, the shorter fasts done regularly and consistently will yield better results in the long-term than longer fasts.
If you’re considering fasting as part of your weight-loss journey, our Medical Weight Loss team can help you find the right approach.
How to Achieve Autophagy?
If you don’t know how to achieve autophagy efficiently, it doesn’t matter how much you know about it. Below are some fasting windows and strategies that help you achieve autophagy:
Step 1: Choose an Eating Window
16:8 protocol
- Fast for 16 hours
- Feed within an 8-hour time frame
- For example: You eat between 12 p.m. and 8 p.m. and fast from 8 p.m. to 12 p.m. the next day
- This is easier to do than it sounds since the hours of sleep are also included in your fast
18:6 protocol
- Fast for 18 hours
- Eat within a 6-hour time frame
- For example, have food from 1 p.m. to 7 p.m.
- This is where autophagy activation is more regular and noteworthy
OMAD: One meal a day (20–23 hours fast)
- One large, nutritionally complete meal per day
- May not be suitable for all individuals
- Must be carefully fed to prevent deficiency
- Daily practice results in substantial activation of autophagy
Extended fasts (48–72 hours)
- Ideally done once a month to once a quarter to maximize the benefit
- Maximum autophagy benefits
- May not be suitable for all individuals
- It requires medical guidance for anyone with a chronic condition, history of eating disorders, or who is on medication
Step 2: Food to Eat During the Fast
This is where most people end up sabotaging their fast. To promote autophagy, insulin must be low, and mTOR must be suppressed.
These do not break your fast or inhibit autophagy:
- Water
- Black coffee (no milk, cream, or sweetener)
- Tea (plain green tea or herbal tea)
- Electrolytes (no calories)
- Sparkling water
These break your fast and inhibit autophagy:
- Coffee or tea with milk, cream or dairy alternatives.
- Fruit juice
- Smoothies
- Bulletproof coffee
- Gum containing calories
- Sugar alcohols
- Any food
- Protein supplements or collagen drinks
Step 3: Make the most of your eating window
The food you consume during your eating window directly affects how quickly you get back into the low insulin or autophagy window of the next fast.
Eat this in your eating window:
- High-quality protein like salmon, eggs, chicken, legumes
- Meats, fish, eggs, legumes, and nut butters
- Leafy green vegetables, cruciferous vegetables, broccoli, and asparagus
- Sweet potatoes, quinoa, moderate amounts of whole grains, legumes
- Blueberries, strawberries, raspberries
Step 4. Work out in a fasted state
When you are in motion, your body has to use energy. Even walking briskly or doing light workouts during the fast period will cause your body to rapidly use up the rest of its glycogen stores. In this way, you enter the autophagy window much quicker than sitting on the couch.
Use other strategies to achieve autophagy
In addition to fasting and exercise, there are some simple, evidence-backed methods which can trigger autophagy on their own:
- Cold exposure. Short exposure to cold (cold showers, ice baths, cold water swimming) activates AMPK, and studies have demonstrated that it induces autophagy in several tissues. Just a 2-3 minute cold water bath at the end of your regular shower has measurable metabolic and cellular benefits.
- Deep Sleep: Autophagy naturally occurs at night while you are sleeping, but only if your blood sugar is stable and you reach deep REM sleep. Having a big heavy meal with high carbohydrate content right before going to sleep means that your body is spending the entire night chewing and digesting rather than repairing. It is easy to avoid eating for three hours before bed to enable your nighttime autophagy process to work properly.
- Heat exposure (sauna). Heat stress leads to induction of heat shock proteins and has been linked to elevated levels of autophagy. The use of saunas, 3-4 times weekly at 170-190 F for 15-20 minutes, has a rapidly expanding evidence base for cardiovascular and longevity benefits.
Signs Your Autophagy Protocol Is Working
At present, there’s no consumer-friendly blood test available for autophagy activation. Below are some indirect signs that suggest your fasting protocol is working:
- Blanched energy throughout your fasting time
- Improved mental focus during fasting times
- Reduced post-meal bloating
- Loss of visceral fat
- Better sleep quality
- Lower chronic inflammation (hs-CRP) on lab tests over months
- Greater improvement in fasting insulin and metabolic markers
Who Should Not Fast for Autophagy
Autophagy fasting is not for all of us. Don’t try extended fasting without provider advice if you:
- Are pregnant or breastfeeding
- Have a eating disorder
- Have a BMI below 18.5 or are underweight
- Have Diabetes (Type 1 and Type 2 diabetes)
- Take medications (diabetes, blood pressure or thyroid medications)
- Have been diagnosed with chronic kidney disease
- Are under acute stress
Bottom Line
With all certainty, Autophagy is an essential biology for long-term health and disease prevention. While understanding how to induce autophagy is one thing, putting it into practice to your health picture is another.
Not all fasting protocols are suitable for everyone, and the best way to reap the benefits of autophagy fasting is to follow the plan to your body, rather than a pre-made program from the internet.
At Kairos Health & Wellness in Houston, Texas, Lola, one of our functional nurse practitioners, takes a personalized functional medicine approach to metabolic health, longevity, and cellular wellness.
If you are interested in discovering your current metabolic state and suitable fasting methods for your health profile, reach out us today!