For my next installment on Resistant Starch, the following post documents an N=2 (two study subjects) collaboration to record blood glucose readings in different states of dieting, with and without RS. The following was assembled by regular commenter Marie (a real life scientist in her day job) and 'Tatertot Tim', the guy who brought RS to Free the Animal months ago and has probably read more of the studies going back 30 years than anyone currently living on the planet.
After reading the information you posted from Tim and yourself on resistant starch, I wanted to verify personally whether my father could take it so that he could get the immunological and gut-healing effects of RS, while staying in ketosis. He is on a severe ketogenic diet for cancer and must remain continually in ketosis.
At that point, Tim and I started to collaborate, looking at a second possibility raised by the literature, that of “blunting” of the Blood Glucose (BG) rise by resistant starch when taken together or before a high-glycemic food. A large (300 gram or 2/3 pound) cooked potato is a good test for this blunting effect, as it normally gives a large rise in BG when eaten without any added resistant starch.
These slides of graphical comparisons tell our story.
1. For tolerance of ketosis to RS/PS, the results are unequivocal. There is NO rise in BG when taking PS alone or with a ketogenic meal. Ketostix also confirm that ketosis is not disturbed.
2. For RS/PS blunting effect when taken together with hi-glycemic food, there is clearly a blunting effect for both Tim and myself, while you can see from my additional results that the degree of that effect depends on the immediate diet history and the long-term use of RS.
(It should be noted that I'm a healthy female in my mid-40‘s with no history of metabolic disease nor obesity and I respond very quickly to diet changes. Tim is a currently healthy male in his mid 40s with a history of significant metabolic issues that have been conquered for many years now. So between us, we span quite a range of backgrounds.)
The strongest blunting effect is under what may be considered ‘normal’ eating conditions for most people; that is, not in ketosis and not prolonged fasting or intermittent fasting. Under such normal conditions, there is only a very small rise in BG (~ 28 points) for me when eating a cooked potato after drinking 4 tablespoon of potato starch stirred in water. Various timings of the PS in combination of the potato were tried, details in graphs. You see no blunting while in actual ketosis, but various levels of blunting effect in other states.
It’s not a surprise to see different responses to fasting as they depend on the length of the fast and state of glycogen stores previously. Long-enough fasting and/or continual ketosis cause a normal physiological insulin resistance which is temporary and reversible, not to be confused with the pathological kind in metabolic syndrome or diabetes.
3. There is also an apparent ‘second meal effect’ or long-term effect from simply taking 4 tablespoons of RS every day, which improves the blunting in a ‘normal’ metabolic state. When LC, in ketosis, or fasting regularly, the blunting was less pronounced or, to state it the opposite way, RS/PS does not afford the same dramatic results. What that means metabolically over the long term is an open question.
OK, now for the version in pictures. Restarting the count.
1. Ketosis is Not Disturbed By Ingesting Resistant Starch Alone.
2. Resistant Starch Blunts Blood Glucose When NOT in Ketosis. The blunting effect of PS is evident when compared to the Control of potato alone. The second control was done to check for any difference in BG response to potato alone after consuming PS daily for two months, but no additional supplementation with or before the meal. The third slide is with supplemental RS/PS.
Control - No RS
Daily RS Ingestion; No Supplemental RS With Meal
Daily RS Ingestion + Supplemental RS Before Meal
Here's a single-graph comparison of the blunting effects when resistant starch in the form of unmodified potato starch is taken an hour prior. This is under normal dietary conditions, not ketosis or significant fasting.
3. Blunting Effect of Potato Starch Under Various Immediate Diet Histories.
4. Blunting Effect of RS/PS In Ketosis; After 2 + Months of Daily RS/PS.
There you have it. Lots of data. For me, it all adds up to the same thing: Resistant Starch is absolutely NOT going to hurt you ever, even if diabetic. If you are in ketosis or fast regularly, the results are not as profound but there appears to be a subtile benefit over time. If you eat a normal, moderate carb diet (150-200g daily) the results are profound, both for daily ingestion and supplemental ingestion with each starchy meal. If you eat SAD and just can't stop, then it's probably most important to be supplementing RS daily.
Supplementing RS is too easy. You can use Potato Starch, Tapioca Starch and/or and even, Plantain Flour. Some of us are doing blends of all three, now. There's even mung bean flour and probably others that will come to light as more and more people keep jumping on our little bandwagon and giving a try for themselves.
Later, I'll do a post with a list of all RS posts with summaries to date.