#3DayCancerPreventionFast: Day 2

Some thoughts at the end of the second full day of our three-day water-only fast, which we began on Sunday, Jan. 24, as Lisa and I have 15 and 18.5 hours remaining to hit our 72-hour goal.

So far we have been able to stick to the water-only regimen, with a mix of filtered water and mineral water.

We are big coffee drinkers, and were both pleasantly surprised that we didn’t have caffeine-withdrawal symptoms Monday morning. Unfortunately that surprise didn’t last, as the withdrawal symptoms came a little later, as Lisa felt really low in energy and I got a headache in the afternoon and early evening.

Taking a tip from Dr. Peter Attia, I did an early morning workout on Monday, both bench press and high-intensity rowing. The idea is to burn out the stored glycogen to accelerate the move to fat-burning.

Interestingly, my blood glucose and ketone readings from before and after my Monday morning workout (at right) showed an increase in blood sugar from 88 mg/dL before my workout to 104 after I had showered and settled in to work.

That’s totally normal, and is the result of my liver releasing glycogen for use by my muscles.

I took readings again at the 24-hour mark of my fast and then at bedtime, which showed that my glucose levels were stabilized due to gluconeogenesis (my liver creating new glucose from amino acids and other circulating substrates), and ketones had begun to climb, reaching 1.1 mmol/L.

With a Glucose Ketone Index (GKI) of 3.6 at bedtime, I was nearing the high level of therapeutic ketosis, but getting there would need to wait until Tuesday morning.

My early morning glucose Tuesday was again 73, but ketones had climbed to 2.2, and by early afternoon those readings were 67 and 4.2, respectively, giving me a GKI of 0.8.

The caffeine withdrawal symptoms were gone, too. We’re supplementing magnesium and salt to maintain electrolyte balances, and mineral water also helps.

In keeping with Dr. Attia’s advice to do lower-intensity cardio on the second and subsequent days of extended fasts, I waited until after work today to do a 45-minute rowing session. Here were my readings before and after the workout, and at bedtime:

Even though I hadn’t eaten for more than 48 hours, because of gluconeogenesis I maintained adequate blood sugar. And with climbing ketones I have had a GKI under 1.0 for the last nine hours.

I got a Keto-Mojo meter for Lisa, too, and as of this evening she also had reached the 1.0 GKI threshold. Our target is to be below 3.0 for a couple of days, and ideally below 1.0 for a day, for maximum therapeutic benefit.

We’re glad to be in the last several hours of our #3DayCancerPreventionFast. Neither of us would say it has been easy, although we really haven’t felt hungry. Empty is different from hungry. Lisa really misses her coffee, and in future fasts we will likely experiment with allowing coffee, and maybe even coffee with a little cream, and see how our glucose and ketone levels are affected.

I think it’s really helpful having a glucose/ketone meter when doing an extended fast like this. It gives us hard data that what we’re doing is having the desired effect, and when we take readings every few hours we can see the progress.

You may not be able to imagine doing an extended fast for cancer prevention, and if you haven’t done some preparation and adaptation I wouldn’t recommend just diving into it.

Check out My Health Journey for the full story of our health improvements, and my #BodyBabySteps for an approach to how I would do it if I were starting today, based on what I’ve learned.

For us it seems like a worthwhile investment in our long-term health, and I’ll share tomorrow’s experience including breaking our fasts in my next post.

Starting a #3DayCancerPreventionFast

Lisa and I have become convinced that a monthly three-day water-only fast is a prudent health maintenance strategy, based on the metabolic theory of cancer.

We know there are no guarantees it will prevent cancer, but the risk of doing any harm is essentially zero.

That doesn’t mean we necessarily look forward to it.

We had designated today as the start for our next #3DayCancerPreventionFast, and as we were getting ready to drive to church in Rochester, Lisa asked if we might listen to something on the way that would help with motivation.

This video from Prof. Thomas Seyfried from just a few months ago was a nearly perfect fit for our 45-minute commute, and it reminded us of the “Why?” behind our decision:

Once we arrived in Rochester, this morning’s service was a special blessing for us, as two of our grandchildren were baptized.

That illustrated the real “Why?” of our monthly 3-day fasts.

What you see above are half of our grandchildren: we have 13 on the outside, with another grandson due in March.

Lisa and I have decided we want to take what a friend calls, “The path of least regret.” We want to do whatever is reasonably in our power to stay healthy so we can be involved in the lives of our sons and daughters, their children and hopefully even their grandchildren.

We want to be there for as many more of these events as we can.

That makes the short-term sacrifice of an extended fast totally worth it if there’s a reasonable basis to think it might prevent cancer.

So on the way home, for just a little extra nudge, we listened to most of another video featuring Prof. Seyfried:

When we got back to Austin, we enjoyed a delightful celebration dinner with the baptized boy’s family, after which Lisa started her 72-hour timer at 1 p.m.

I decided to add one more highly ketogenic meal in the late afternoon, and started my timer at 4:30 p.m.

An hour after that meal my blood glucose was 85 mg/dL and ketones were 0.6 mmol/L, which put me just barely out of GKI ketosis with an index of 9.4.

But as I write this with just under 68 hours left in my fast, here are my latest glucose and ketone measures:

It’s good to be already in GKI ketosis, and I’m heading to bed so I can get up early tomorrow for a workout to jump start autophagy and hopefully accelerate progress toward the 1.0 GKI target.

As we continue our #3DayCancerPreventionFast I hope you’ll follow along as I share observations on FacebookTwitter  and LinkedIn.

I’ll also write a daily recap post here that you can receive if you subscribe by email.

Check out My Health Journey for the full story of our health improvements, and my #BodyBabySteps for an approach to how I would do it if I were starting today, based on what I’ve learned.

Why I settled on Three Days for Cancer-Prevention Fasts

Intermittent fasting and time-restricted eating have been a huge part of my health journey and of Lisa’s, thanks to an introduction to the concept from Dr. Jason Fung.

When we tried 10 weeks of alternate-daily fasting, that was when Lisa really started to see impressive weight-loss results.

Now fasting is just part of our routine. As I’ve tracked with the Zero app, I have fasted at least 13 hours on 269 of the last 270 days.

Usually I have two meals a day, four to eight hours apart. Sometimes it’s just a single meal, a.k.a. One Meal A Day or OMAD, which is what Lisa typically does.

Occasionally we fast for more than 24 hours to accelerate autophagy and for cancer prevention.

I believe I first heard of the idea of fasting for cancer prevention through Dr. Fung, primarily in the context of how long-term caloric restriction has been demonstrated to increase longevity and to reduce cancer incidence, both in animals and in people.

But who wants to live like that all the time?

What if you can get most of the benefits of chronic restriction through periodic pulses of fasting, while eating normally the rest of the time?

That leaves the question of dosage: how long does the fast need to be, and how frequently do you need to do it?

The short answer is no one really knows, but here is why Lisa and I have settled on three days once a month.

I had heard about Dr. Peter Attia’s practice of a seven-day water-only fast (a.k.a. the Nothingburger) once per quarter as a potential cancer-prevention strategy, and so I decided to try a seriously extended fast for the first time about 15 months ago.

Instead of water only I also allowed myself coffee, and I went five days, from Sunday evening to Friday evening. I did another of these last February, but cut it to four days because my sleep quality the previous night hadn’t been good.

Meanwhile I heard that Dr. Attia had changed his personal practice to a three-day fast each month. It’s two more days of fasting per quarter, but spread out over three months instead of all at once.

As I said, no one knows the “right” dose and frequency, but this seemed like something worth trying.

In November and December I did three-day fasts. The slightly lower intensity than my previous 4-5 day fasts was appealing, but I still had that nagging question of whether it was enough.

Then I finally checked out some videos from Professor Thomas Seyfried (as highlighted in my last post) on the metabolic approach to cancer treatment through a ketogenic diet and related interventions.

He described the glucose-ketone index (GKI) he had developed to measure whether patients were in an optimal, deep level of ketosis. A GKI of 9.0 or less indicates some level of ketosis, with 1.0 or lower being the highest therapeutic level.

Increasing ketones and reducing glucose allows normal cells to thrive, while cancer cells – which lack the ability to use ketones for energy – are placed under stress.

I also was interested in confirming that my normal blood sugar levels weren’t masking an underlying condition called insulin resistance. If I had normal blood sugar levels only because my pancreas was cranking out lots of insulin, that would not be healthy.

I felt pretty confident that I had reversed any insulin resistance I may have had before my weight loss, but I wanted to confirm it.

Testing insulin levels is complicated and expensive, but I had learned that having ketone readings of 0.5 mmol/L or higher is a back-door way of confirming low insulin levels. They’re in a reciprocal relationship: elevated ketones aren’t compatible with high insulin.

I also heard someone mention the Keto-Mojo device that enables home measurement of blood glucose and ketones, and which enables tracking through a mobile app, so I took the plunge and got a starter kit for about $100.

My Keto-Mojo arrived the day after I started my December fast, and that evening my GKI was 3.2. By the 48-hour mark of my fast I reached 1.0 and I stayed below that (0.8, 0.5 and 0.5) until I broke my fast 24 hours later. I remained below 3.0, which is considered high-level ketosis, for another 24 hours. I maxed out at 6.2 mmol ketones with blood sugar at 61 mg/dL.

It seems that if GKI at or below 1.0 is the therapeutic target for those undergoing metabolic cancer treatment, being there for at least 24 hours once a month gives a reasonable chance of being helpful in cancer prevention.

It isn’t rock-solid confirmation for the three-day fast Dr. Attia uses, but it gives me some reason to believe I’m in a fasting range that should be beneficial.

I think Professor Seyfried put it well toward the end of the video I embedded in my last post:

These are non-toxic approaches. I can’t tell you whether it’s going to be the solution to the cancer problem. But I can tell you ‘I think it works, and it’s not going to hurt you. And it has the potential mechanistically to be very effective.'”

Thomas Seyfried, Ph.D.

Our next three-day fast starts tomorrow afternoon. This time I’ll be working to ensure I’m in ketosis before I start my fast, which should make it easier, and also will be taking GKI readings throughout the full fast instead of starting partway through the fast.

I’ll also explore strategies to get to that GKI ≤ 1.0 as quickly as possible to have the greatest therapeutic effect.

I’m not asking you to join Lisa and me in this fast, but if you’re curious I do invite you to follow along as I share observations on Facebook, Twitter and LinkedIn.

I’ll also write a daily recap post here that you can receive if you subscribe by email.

Check out My Health Journey for the full story of our health improvements, and my #BodyBabySteps for an approach to how I would do it if I were starting today, based on what I’ve learned.

Fasting for Cancer Prevention

While extended fasting can have a broad range of benefits, the real reason for my monthly three-day fast is for cancer prevention.

Professor Thomas Seyfried of Boston College, one of my Health Sherpas, has pioneered research that has significantly challenged the somatic mutation theory of cancer, which holds that cancer results from an accumulation of random DNA mutations in the nuclei of cells, which cause them to grow out of control.

Seyfried has championed a metabolic theory of cancer, which essentially says that cancer results from damaged mitochondria, the power plants of the cell.

The video below, in which he addresses a lay audience, provides a compelling presentation of his case.

He first dismantles the somatic mutation theory by showing how it is incompatible with the results of several studies.

He then convincingly describes the metabolic theory of cancer and how it better fits the data, explaining how cancer cells can have so many different mutations in the nuclear DNA, and yet have so many features in common.

The damaged mitochondria generate reactive oxygen species (ROS) that cause the DNA mutations in the cell nucleus. Those mutations are downstream from the real cause of cancers.

This video from last September is more technical, but also includes some updates on applications of his theory in cancer treatment. It’s worth watching if you want a deeper investigation.

Watch the video below first for an introduction, and afterwards scroll down and I’ll describe why I see a monthly three-day fast as a valuable cancer-prevention strategy.

You did watch it, right?

If not, hit the play button and read on when you’re done.

As Professor Seyfried explains, cancer cells use fermentation of sugar to generate energy, and lack the flexibility to use oxygen and ketones because of damaged mitochondrial structures.

As I mentioned previously, one of the benefits of fasting is autophagy, which causes cellular cleanup and recycling of defective organelles like the mitochondria. So one cancer-prevention mechanism is replacing mitochondria that are throwing off ROS and causing mutations with new and improved versions.

The second mechanism is by introducing ketosis at a level that is far beyond a typical ketogenic diet. We all have lots of cancer cells in our bodies at any given time, and our immune system kills off many of them.

But as Professor Seyfried says, cancer cells have lost the metabolic flexibility to use ketones for energy because of their damaged mitochondria. An extended fast drives ketone levels high enough to cause the remaining cancer cells to die, or at least slows their ability to grow and proliferate.

Ketones and blood sugar are inversely related. As blood sugar goes down due to caloric restriction (or a fast), ketone levels go up. And as glucose goes up, tumor size increases.

“It doesn’t mean that sugar causes the cancer, but if you have the tumor, the tumor will grow faster with the higher blood sugar.”

Professor Thomas Seyfried

Later in the video, in the Q&A session, Professor Seyfried describes meeting members of the Calorie Restriction Society of America, people who severely and continuously limit their food intake, and how they have virtually zero incidence of cancer.

He also suggests that long-term caloric restriction is no way to live.

I agree with that.

I see periodic episodes of extended fasting as a way of getting most of the benefits of long-term caloric restriction without the soul-crushing grind of continual deprivation.

As I said in my last post, no one really knows how long is long enough for these extended fasts, or how frequently they should be done.

In my next post I’ll describe why I’ve settled on a three-day fast once a month as my dosage, with a low-carb, high fat (LCHF) lifestyle and time-restricted feeding as the foundation.

If you think your friends might find this post helpful, I hope you’ll share by email or on your social networks using the buttons below.

To get these updates on a regular basis you can subscribe by email, or follow me on FacebookTwitter and LinkedIn, where I’ll also be posting links.

Check out My Health Journey for the full story of our health improvements, and my #BodyBabySteps for an approach to how I would do it if I were starting today, based on what I’ve learned.

Why do a three-day fast?

I’m not suggesting you should do an extended fast. In fact, I wouldn’t recommend it until you have:

  1. Become fat-adapted through at least four weeks of a low-carb, high-fat ketogenic diet, and
  2. Become comfortable with time-restricted feeding, with several weeks of maintaining fasting windows of 18-24 hours.

Doing #1 makes #2 much easier, but don’t rush it. Focus on eating your satisfying low-carb meals when you feel hungry, and start by avoiding post-dinner snacks.

Your goal is to achieve metabolic health, not to demonstrate willpower.

But once you feel established in a ketogenic eating pattern and have done some alternate-day fasting, extended fasts can create some impressive metabolic health benefits by unleashing autophagy.

Autophagy literally means “self-eating.” When nutrients are scarce, your body goes into this clean-up mode in which it digests and recycles cellular parts that are weak or defective, and replaces them with newly generated ones. See an excellent explanation of autophagy by one of my Health Sherpas, Dr. Jason Fung.

For a compelling overview of the benefits of autophagy, here’s a helpful video from another of my Sherpas, Dr. Sten Ekberg:

If you didn’t watch the video, the benefits Dr. Ekberg cited included:

  • Anti-aging – caloric restriction has been shown to improve lifespan, and many of these same benefits are thought to result from periodic extended fasting.
  • Detoxification as damaged proteins are recycled
  • Immune system enhancement
  • Improved tissue quality
  • Lowered insulin levels and increases in growth hormone
  • Reducing skin sag with weight loss, as the extra skin is broken down and recycled.
  • Brain-related benefits ranging from traumatic brain injury recovery to symptom improvement in Alzheimer’s and Parkinson’s diseases.

Even a relatively brief period of fasting triggers autophagy at some level, but to significantly activate it likely takes a couple of days or more. But unlike ketosis, which can be detected with a simple breath or finger-stick blood test, demonstrating autophagy requires a muscle biopsy.

Still, I think the framework Dr. Ekberg suggests is likely accurate: if you’re eating the Standard American Diet (SAD), you’ll likely take 72 hours or so for meaningful autophagy, but if you’re already fat-adapted it happens much sooner.

So I think given the eating pattern Lisa and I have been observing for more than a year, we’re likely getting a dose of autophagy with our 18-24 hour fasts.

One of the most compelling implications of autophagy is in cancer prevention, but no one really knows yet how large the dose needs to be.

This has been an topic of significant research interest and speculation that I will discuss in my next post.

If you think your friends might find this post helpful, I hope you’ll share by email or on your social networks using the buttons below.

To get these updates on a regular basis you can subscribe by email, or follow me on FacebookTwitter and LinkedIn, where I’ll also be posting links.

Check out My Health Journey for the full story of our health improvements, and my #BodyBabySteps for an approach to how I would do it if I were starting today, based on what I’ve learned.