Part 1 of this 3-Part series dealt with incorporating a diversity of fermentable fiber in the diet as more ideal than isolated RS alone. Part 2 dealt with the difference between raw RS2 resistant starch and RS3 retrograded resistant starch. In this final post in the series, we cover what sources of foods you can use to up your RS3 intake.
Much of our frustration in reviewing hundreds of studies conducted over 30 years on Resistant Starch was the observation that there was not much dietary recommendation—beyond silly stuff like eat more cold potato salad! But, early on in our experimentation, we discovered how easy it is to work your food food into a form more in line with the ways our ancestors ate their food, e.g., cool-reheat-recycling. This creates RS3 (retrograded resistant starch) from staple starches.
Many studies of diets around the world show that most westerners are getting 3-5g/day of RS, another 3-5g/day of inulin (mostly from wheat), and less than 15g/day of total fiber. This is a far cry from the 80g eaten by poor, rural, modern day Africans subsisting on stale maize porridge, or the 135g+ fiber eaten daily by Paleo-Indians of North America. 15g/day of total dietary fiber probably ensures a person can form a stool and break occasional wind, but this is also the gut of the Pepto-Bismol generation. At any rate, you'll find that shooting for 20-40g of RS3 from real foods also gets you a good bit of other fibers. Here’s a list of international RS3 rich foods (link removed) that are low glycemic index carbs, to feed both your muscles and microbes.
Most people will be getting their RS3 from potatoes, rice, and beans. Of the three, beans have the most total fiber in various forms. But many folks eschew beans, due to their demonization by The Paleo Diet™...and perhaps also, their propensity to reward flatulence in unaccustomed gut biomes. We assert that this is a monumental blunder that persists unchanged, largely unchallenged, unedited, un-reconsidered—now, a Catechism. A Doctrine. But beans or legumes have a long history of feeding some of the healthiest, longest-lived populations on earth. Unfortunately, "science" is often unmoved by real world observation. Oh, well. You get to decide anyway.
...Moreover, we're far more concerned with what's actually healthy and beneficial long-term—for both the 10% of you, and 90% of them—than in adhering to catechisms and doctrines about how much protein and fat ancestors ate to the exclusion of the other foods they could have, in many cases, more easily gathered and eaten. It doesn't make sense on even more levels than health claims.
Certainly, many of you know the pain of counting calories. Many of you have also counted carbs, fats, or protein (excepting proteins like snake venom and others of the most poisonous substances on earth). It's fine to do so, to count and account, to gain insight into what you're eating—much like tracking your money to see why you're a dollar short at the end of the month. As a long-term strategy, though, it never works as planned for non-OCD people. For most, it's better to just learn to recognize the foods that are rich in RS and other fibers, and include them in your diet regularly. The last thing we want to do is create another program that requires meticulous tracking and counting.
...Here's another tidbit we've discovered along the way, while researching RS: Approximately 10% all all ingested starch, resistant or not, escapes digestion in the small intestine and serves as fuel for gut microbes. Some foods even contain natural amylase inhibitors. Might this be an evolutionary adaptation to feeding our critical gut bugs? So, just eating starchy foods will feed your microbiome a reasonably healthy dose of fermentable fibers. So, alas, rather than spend valuable time counting RS in the foods you eat, just include beans, rice, and potatoes in your healthy eating patterns to various degrees, including from hot off the stove to frozen, thawed and reheated—or eat them cold, sometimes. (To maximize RS, you pre-cook and cool them. This not only increases the amount of retrograded resistant starch, but makes these time-consuming staples almost a fast-food. Can it get any easier than that?)
Some other tricks to increase your RS intake: use parboiled rice, like Uncle Ben's Original. In theory, it contains higher RS as it's been pre-cooked and cooled. If you don’t care for Uncle Ben's, choose long-grain pigmented rice, i.e., brown, red, or black types, for more RS (and antioxidants) than your typical long-grain white rice.
Potatoes are a bit higher in RS content, compared to rice, but also contain 10g of fiber (not counting RS) per pound; and again, the purple varieties of potatoes have more RS and antioxidants than standard varieties. Beans of all sorts contain about 10g of RS per cup, but also 20g of other fiber. Also, consider the myriad other sources of RS3-producing foods like plantains, quinoa, lentils, and yams. Corn can be a wonderful source of RS—but many are (rightfully so) opposed to corn due to GMO concerns. Eat lots of foods that contain edible seeds: blueberries, strawberries, bananas, etc..
Did anyone catch the important insights left by DuckDodgers in a comment last week:
I've uncovered evidence that traditional cultures all over the world have been creating lots of RS3 for a very long time.
Biology and Chemistry of Jerusalem Artichoke: Helianthus tuberosus L., by Stanley J. Kays, Stephen F. Nottingham
"Precooking the tubers has been a culinary practice for many years and is mentioned, for instance, in the 1633 edition of Gerard's Herball and in the 1738 edition of La Varenne's le Cuisinier Francois."
Indian tribes actually made RS cakes!
"Elephant foot yam chutney with or without dry fish is [a] common dish among the tribes of Tipura and Meghalaya...Cooking the elephant foot yam in bamboo shoot ash water and after decanting water, the cooked tubers are made in to paste and dried in the form of a cake. After drying, the cake is again cooked in bamboo shoot ash water and dried in sun after decanting ash water. This dried cake can be stored for 30-45 days without any quality deterioration."
And my personal favorite...
North American Cornucopia: Top 100 Indigenous Food Plants, by Ernest Small
"Duck potato was in fact a staple food for many Indian tribes. On boiling or roasting, the tubers became pleasant in taste. Some Native North Americans sliced boiled tubers and strung them on twine to dry and store for winter use (dried tubers store about as well as potatoes)...The dried tubers can be ground into a flour."
And then we have the "Blue Zones" where people tend to live exceptionally long lives for a number of reasons. But, it turns out, most of those "Blue Zone" cultures have one thing in common that nobody really notices. They were all relatively poor [Grace: and have soil exposures via gardening and farming!]. And what do poor people do?...
"Sardinians were poor for most of their history. And so their diet is incredibly simple and frugal. Their traditional dishes are about using up leftover pasta, bread, meat and cheese."
Yep. They were saving all their foods and inventing ways to reheat them because they didn't have the resources to waste their food.
The Nicoya (another "Blue Zone") in Costa Rica had their Gallo Pinto, a leftover rice and beans dish. In Panama and in El Salvador, they call it Casamiento. In Cuba it's known as Platillo Moros y Cristianos.
Tuscans have their Ribollita. "Bubble and Squeak" is a famous leftover potato/meat dish in Europe, and just about every European culture had their own version of it.
Wherever we look, we see a long tradition of saving foods and dreaming up new ways to reuse them.
There were also societies that utilized isolated, raw starches (RS2) in a variety of interesting ways, but never as a main source of calories and nourishment.
- Horchata de Chufa, a tigernut starch drink that is still enjoyed by many around the world today;
- Fufu, a starchy dough made from cassava root eaten in Africa;
- Chicha, similar to Horchata de Chufa but made with corn;
- Chuno, a dehydrated potato staple of the Andes;
- Tororo, made of the Asian yam Dioscorea opposita, often eaten with Natto;
- Nuts and Seeds. Probably every single culture enjoys munching on raw nuts and seeds. Sunflower seeds, pumpkin seeds, chia, flax, and all manner of tree and ground nuts are universally enjoyed by people around the world and contribute to a healthy gut.
Looking back at our original set of parameters, we still have a ways to go, but here's the progress we've made:
- What is the optimal dose? Approximately 20g conventional fiber and 20-40g per day RS (RS3 or mix of RS1, RS2, RS3);
- What is the optimal source? Real foods that provide a combination of RS and other fermentable fibers;
- Will it make a difference in the grand scheme of things if implemented on a world-wide basis? Undoubtedly, and we're quite fucking sure about that!
- Is it contra-indicated for anybody? Rather ironically, those who need it most are the ones who will have the most trouble tolerating and getting up to speed with these recommendations. Various levels of gut dysbiosis leave people unable to ferment prebiotic food, or it is fermented by pathogens. On the bright side, there are a number of people in that state, figuring it out and passing on their knowledge.
- RS supports a healthy gut microbe population. ...But only if the healthy gut microbes are present;
- RS exhibits undeniable effect on glucose control and satiety. Glucose, yes; satiety, mixed results;
- RS in amounts of 20-50g /day are well tolerated. ...Unless the gut is already compromised by pathogens or disease;
- RS can come from many sources including real food. Absolutely! It's the point, now that we've seen so many thousands of positive anecdotes even on less optimal isolated RS, like potato starch.
So far in 2014—less than 6 months in—there have been 51 papers released on PubMed with resistant starch in the title or abstract. Interest in RS is not waning but increasing—and we're gratified to be a collaboration of leaders in the RS popularsphere. What a marvelous opportunity that has rewarded countless improvement in real lives...and in so many cases, correcting problems from faulty popular errors that involve starving the gut; i.e., very low carb and ketogenic diets in chronic, rather than episodic practice.
The most recent paper, released just this week, is an RS3 animal study with human implications:
The study concludes:
Possible underlying mechanisms for RS-induced satiety include increased 24h plasma SCFA levels, and decreased postprandial glucose and insulin responses. GLP-1 and PYY seemed not to play a role in RS-induced satiety. Low blood serotonin levels in RS-fed pigs suggested a difference in intestinal serotonin release between treatments. Increased postprandial plasma triglyceride levels corresponded with increased SCFA levels, but it is unclear whether triglycerides may have signalled satiety in RS-fed pigs.
So you see, it's not just us with unanswered questions, it's everyone. When you consider the interactions of RS and 100 trillion gut microbes in up-to 1,000 species in snowflake diversity per individual—and its effect on the brain-gut connection—it becomes massive. Eventually this will all get sorted out. Or not, and we'll just toss our hands in the air, seed and feed.
Until then, we’ll keep an eye out for even more daily revelation...whilst others focus on only 10% of you, trying hard to motivate you—day after day—to starve and maltreat 90% of the cells within the borders of your skin. Good luck with that.
We assert that they—from VLC to trademarked Paleo (unchanged since 2002)—will lose. We're looking forward to it, because it can only mean healthier guts in the context of quality foods, and healthier people—free from the unintended consequences of VLC and meat-fat-non-starchy-vegetable "Paleo" diets.