Ketones, Cancer, and Fasting
There’s 3 awful hot button topics in one title, perfect. So lets break this down, there’s a school of thought that keto is the best diet because it significantly decreases your risk for cancer. Is there any scientific data to support this? Actually yea. Cancer cells are amazingly efficient at using glucose to proliferate (rapidly increase cell production) so if blood-glucose levels are high its more food for the cancer cells. Cancer cells also lack the ability to use ketones efficiently for energy, meaning it can drastically effect growth. I can literally hear the Ketozites (like that term? Just made it up) screaming from their trench “I told you, Keto or death!”. Well hold on a second, I’ve already stated we produce ketones on our own even when not in ketosis (stated in my previous article “What is keto and how does it work?), also things like MCT can bypass certain process and be used for energy even when glycogen is present. Being someone who is overly curious and knowing there are no absolutes, isn’t that worth exploring?
Can we slow the growth of cancer cells with ketones while avoiding eating bacon and cheese all day? Yes. The International Journal of Cancer (seems legit) proved just that. Using a test on mice with tumors they tested the effects of a regular diet with added ketones looking at survival rate, tumor growth, etc.. The Ketones used were 1,3‐butanediol or a ketone ester, these are what the body turns into the more commonly known keto supplements βHB and acetoacetate (βHB is easily purchased most places supplements are sold, or pyramid schemes from your long lost friend from high school who randomly messaged you, thanks Ketozites..). The study showed even just the introduction of these ketones to a normal diet increased survival time of systemic metastatic cancer (cancer that has spread throughout the body) by up to 69%.
Summing this up, Keto does seem to be beneficial for cancer prevention and even treatment. We can also use exogenous ketones to somewhat the same effect without going into ketosis, though not as ideal for true prevention, based on studies. Now on to fasting and how this ties in.
Is fasting the best way to get into ketosis?
Best way? Completely dependent on the person. Fastest way? When paired with exercise, absolutely. Studies show that glucose stores in the body are depleted the fastest when the body is fasted and exercise is used to accelerate the depletion of glucose in the body. This forces the body to switch to a new fuel source (ketones) much quicker than the normal keto approach, albeit at a much harsher approach. Since the brain uses 25% of our bodies glucose you are going to feel the effects of glucose depletion, as you switch into ketosis, here first. Symptoms from feeling foggy and lethargic, to irritable and weak are common and can pursue up to 2-3 weeks. If any carbs above the allotted amount are consumed, then the process of ketosis begins all over. This is a very strict diet and, while it has many health benefits, is not the best choice for everyone.
Follow up question for the curious, does fasting produce more ketones than the regular keto diet? Yes, and some studies show by as much as 6x the normal amount. This would mean your body is using the most fat when you are fasted, obviously since there is no other fuel source being consumed. Long term fasting however becomes unideal for overall health as the body will begin to shut down certain functions and muscle atrophy will begin to occur quickly (as little as 3 days).
My opinion, the transition into ketosis can be most easily adapted (minimal “side effects”) if we use all our tools intelligently. Using a short fast, paired with ketone supplements like βHB, leading right into a normal Keto diet (70-75% fats, 20-25% protein, 5% carbs).
Sources
Ketones with regular diet inhibits cancer
https://onlinelibrary.wiley.com/doi/full/10.1002/ijc.28809
Keto diet slowing/preventing cancer
http://cancerres.aacrjournals.org/content/71/13/4484.short
Ketosis without fasting
https://journals.sagepub.com/doi/abs/10.1177/088307380201700305