The Bulletproof Perspective on “Safe Starches”

By: Dave Asprey
August 12, 2012

At the Ancestral Health Summit at Harvard University this week, one of the more interesting panels titled “Safe Starches: Are They Essential on an Ancestral Diet?” was moderated by Jimmy Moore, of low carb cruise fame. (I’m speaking on next year’s Low Carb Cruise.)

Sadly, as I write this, I’m not at AHS on the panel because I am in Singapore for the week speaking at two conferences about cloud security.  The panelists who could actually make it to AHS included Chris Kresser and Paul Jaminet, both guys I respect very much who argue that starch is an essential food, and Dr. Ron Rosedale and Dr. Cate Shanahan on the ” starch is evil” side. I also respect Dr.’s Rosedale and Shanahan’s research. None of these are experts whose advice I would outright disregard like I would Dr. Ornish’s, yet there is a considerable distance between their reasoned conclusions.

To make up for not being on the panel, here is the Bulletproof perspective on starch, compared and contrasted with the views of these other experts. Special thanks to Chris Kresser for his summary of the discussion at AHS.

To be  clear, My Bulletproof Diet, The Rosedale Diet, Jamine’s Perfect Health Diet, and Chris Kresser’s recommendations are all in the same general camp of high fat, low to moderate protein, and low starch, but starch is one of the big areas of disagreement. Mycotoxins and biogenic amines are another area that I believe needs more attention.

The Starch Controversy Players

From a starch perspective, one side of the argument is that glucose, the breakdown product of starch, is flat-out bad for you, so you shouldn’t eat any starch. The other side says it’s vital. Here is a summary of the arguments from some of the leaders in the field.

Dr. Rosedale

Dr. Rosedale believes that we all have at some degree of corruption in insulin and leptin signaling, and this causes chronic diseases of aging such as type 2 diabetes, cardiovascular disease, osteoporosis, obesity, and even many cancers. I am a fan of Rosedale because he thinks about epigenetics, the topic of my book that is coming out in only 4 months!

Dr. Rosedale believes that evolution is optimized for fertility, not longevity, and that eating starch decreases longevity. He also says “Post reproductive death is extremely natural. We can only rely on science, especially the science of the biology of aging, to show how to live a long, post-reproductive lifespan. “ So he’s not excessively focused on what our cavemen ancestors may have eaten, although he considers it.

Chris Kresser

Kresser is another epigenetics fan and I love his work. He argues that:

  • healthy people are different from sick people and healthy people can handle starch
  • there are populations that eat crazy amount of starch and appear to be healthy
  • the amount of starch you should eat depends on your activity level and your genetics
  • humans have a lot more copies of the gene AMY1 that lets us break down starch than other primates

Cate Shanahan

Shanahan is awesome because she pays so much attention to food quality, feed quality, and animal stresses in her Deep Nutrition program.  She arrived at the zero starch zero sugar conclusion.

 Paul Jaminet

Jaminet has been on my podcast and is an amazing guy. He believes that some forms of starches are helpful, especially white rice and potatoes. He says,

The concept of “safe starches” has nothing to do with their glucose content. “Safe starch” is a term of our invention and refers to any starchy food which, after normal cooking, lacks toxins, chiefly protein toxins. We do not consider glucose to be a toxin, though it may become toxic in hyperglycemia.”

This is some seriously bulletproof thinking! Every food on the bulletproof diet is ranked according to the amount of anti-nutrient and toxins as well as macronutrients and micronutrients. This is why, for instance, the rapid fat loss protocol includes sweet potatoes and white rice once or twice a week, but I never recommend starches like grains.

 Stephan Guyenet

And while he was not on the panel, Stephan Guyenet also deserves mention here for his work on starch, which his in alignment with Jaminet, but includes reference to the usefulness of glucose in forming polysaccharides that make mucus.

Enter biohacking

So given all this amazing brainpower working on the starch problem, and  the diametrically opposed opinions, what is a biohacker to do?

You probably already know the answer. You experiment on yourself.

Results of my extreme low carb experiments

I have been in the “starch is bad” camp but for years but found it unnatural to get below 50 g a day for longer periods of time. But as an experiment, I went for 90 days on a grass fed meat, butter, MCT oil, and egg version of the Bulletproof diet with very few vegetables, about 1-3 servings a day. I did get a little leaner but several (now) predictable things happened:

Dry eyes

I got extremely dry eyes. Guyenet’s work explains why this happened; I didn’t have enough glucose to form mucus that is a part of the coding in my eyes. If I had continued the diet with near 0 carbs I would likely have suffered gut permeability issues when I ran out of mucus to protect the lining of my stomach from stomach acid.

Poor sleep

My quality of sleep declined. I found that I woke up feeling exhausted even if I got normal amount of sleep for me. My Zeo showed that I would wake up approximately 9 times per night but had no recollection of it. My amount of deep restorative sleep plummeted to near 0. My brain was literally starving for glucose and was waking me up to go find some.


My longstanding thyroid problem appeared to get worse, although I did not measure it at the time. I simply upped my dose of sustained release bioidentical T3 after a while which resolved the symptoms. Enter the work of Chris Masterjohn who has also been a guest on my show. He writes about the role of LDL receptors in cardiovascular disease in The Central Role of Thyroid Hormone in Governing LDL Receptor Activity and the Risk of Heart Disease. The basic story is that thyroid hormone stimulates expression of the LDL receptor in cells which causes LDL receptors to be generated on the cell membrane. So if your T3 is higher you will have more LDL receptors which means your cells will use LDL for energy better. If your T3 is lower, your cholesterol goes up by your cells have less energy.


My LDL went up by 30 points.  As I’m in Singapore, I don’t have the exact numbers with me to share. As Jaminet writes, high LDL with low carb may be a sign of:

  • A chronic state of glucose deficiency, leading to very low T3 levels and suppressed clearance of LDL particles by lipid transport pathways.
  • Absence of infections or oxidative stress which would clear LDL particles by immune pathways.

In my case, my other inflammatory markers were unchanged; my triglycerides were under 70 and my lpPLa-2 was very low, my CRP was low, etc. I do not worry about unoxidized LDL levels because your body will use LDL to bind to and eliminate environmental toxins. It’s not well known, but people with high cholesterol survive certain drug overdoses and toxin exposures better than people with low cholesterol. I believe unoxidized cholesterol is protective and not harmful. Yet, an extreme low-carb diet did raise my LDL.

Bulletproof Starch – It’s all about the timing

My starch recommendations are more fully explained in the upcoming Bulletproof Diet v 3.0 in the next few weeks, but my approach to starch and even fructose differs significantly from these other experts.

I believe that having starch constantly present on a daily basis is a bad idea because it will feed bacteria in your gut, and even if you take probiotics, your gut biome is almost hopelessly jacked compared to the way it should be. The things we’ve done to the planet’s bacterial ecosystem by using antibiotics and fungicides have come back to haunt our gut bacteria. I also fully comprehend the cognitive and biological benefits of ketosis and eating starch on a daily basis doesn’t lend itself to being in this important fat burning metabolic state.

That’s why I recommend you eat a moderate amount of starch, about 100-150 g, every 3 to 7 days. I recommend you eat it in the evening before bed because it will improve your sleep quality by creating glycogen which your brain will use. This will effectively cycle your body in and out of ketosis, avoid overfeeding gut bacteria you don’t want, and provide raw materials for forming tears and mucus.

I also recommend that, on zero starch days, you consume up to 1 tablespoon of raw honey before bed along with MCT oil. Raw honey forms liver glycogen preferentially compared to other forms of sugar, and liver glycogen fuels the brain better than muscle glycogen. Some people don’t need to do this, but if your sleep quality improves, it’s an easy biohack that doesn’t take you out of ketosis thanks to the wonderful powers of MCT oil.

The toxin connection

I also stand with Paul Jaminet when it comes to safe starches, namely sweet potatoes and white rice. These are lowest in protein toxins. However, there is more to the toxin story in starch then naturally occurring protein toxins. Starch is a preferential food for mycotoxin forming fungi like Aspergillus and Fusarium. The vast majority of starch-based foods get fungal contamination during processing or storage, and those toxins affect your gut, your brain, and your health.

I do not believe white potatoes are a smart food to eat because as members of the nightshade family they contain lectins, proteins that bind to the sugars that coat the cells in your body and cause inflammation. Potatoes are also notorious for harboring mold and there are more than 20 things you need to do to store them properly to avoid introducing new toxins as they age, especially mycotoxins. They are simply a high-risk food. Fortunately, sweet potatoes are not the same.

So there you have it. Enjoy roasted sweet potatoes soaked in butter for dinner once or twice a week, or maybe have baked mochi (white rice) stuffed with grass fed butter and drizzled with raw honey for dessert. Just don’t do it every night. This is my primary way of achieving low-carb benefits without the established problems that come from long-term low-carb dieting. Proper timing of carbs is one way the Bulletproof diet works like it does. A long term, high-fat, moderate protein, low carb diet won’t do the same things by itself.

Special thanks to Paul Jaminet, , Stephan Guyenet, Chris Kresser, Dr. Ron Rosedale, Chris Masterjohn, Dr. Cate Shanahan, and Jimmy Moore for the focus they’ve paid on the safe starch issue.