My Perspective on “Safe Starches”
By: Dave Asprey
August 12, 2012
At the Ancestral Health Summit at Harvard University, 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.
The panelists 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 my 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 point of view, the Rosedale Diet, Jaminet’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 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.
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.
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
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.
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.”
Every food on the Bulletproof Diet is ranked according to the amount of anti-nutrients and toxins, as well as macronutrients and micronutrients. This is why, for instance, I recommend eating sweet potatoes and white rice once or twice a week, but I never recommend starches like grains.
And while he was not on the panel, Stephan Guyenet also deserves mention here for his work on starch, which is in alignment with Jaminet, but includes reference to the usefulness of glucose in forming polysaccharides that make mucus.
My stance on starches
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 eating a moderate amount of starch, about 100-150 g, every three to seven days. I recommend eating 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 stand with Paul Jaminet when it comes to safe starches, namely sweet potatoes and white rice. These are lowest in protein toxins.
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 step that doesn’t take you out of ketosis thanks to the wonderful powers of MCT oil.
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.