Many thanks to Richard Nikoley, Tim “Tatertot” Steele and Grace Liu for not only giving comprehensive answers to my many questions about resistant starch, but for taking the time to answer questions in the comments section as well. I appreciate your dedication, gang.
Speaking of the gang, Richard was the guest host for the latest episode of Jimmy Moore’s Livin’ La Vida Low-Carb show. Tim and Grace were his primary guests. I came on at the end. The topic, of course, was resistant starch.
I started the three-part interview series by saying my next few posts should be filed under Stuff I Got Wrong or Stuff I Wish I Hadn’t Ignored. Resistant starch was one. Okay, got that one covered for now. The other was “safe starch” as prescribed in Paul Jaminet’s Perfect Health Diet.
I’ve already explained why I dismissed resistant starch when the topic first hit the media: the people pushing it were the makers of an industrial corn product that’s used to add a little resistant starch to muffins and other baked goods that are still frankenfood garbage. They’re still promoting resistant starch that way.
I mostly ignored the “safe starch” issue when it created a buzz in 2011 because I’d given up starchy foods and felt fine. In fact, I didn’t even watch the Ancestral Health Symposium debate on safe starch until last week. I say mostly ignored because the one time I commented on it was when Jimmy Moore wrote a blog post and asked for a comment. I hadn’t read the Perfect Health Diet book, but knew Jaminet recommended a diet that included “safe starches” such as white rice, potatoes, sweet potatoes, yams and plantains to avoid a glucose deficiency. So I made a wisecrack about how my Irish ancestors died off from a glucose deficiency because they didn’t have access to white rice, potatoes, sweet potatoes, yams and plantains – none of which are native to Ireland. (Potatoes didn’t come to Ireland until they were brought from the New World.) Then I went back to ignoring the topic.
I did, however, start adding sweet potatoes and squashes back into my diet here and there after I read more on paleo and ancestral diets and realized that tubers and other starchy plants have been part of the human diet for a long, long time. Unlike wheat and other cereal grains, roots and tubers are not Neolithic foods that require farming and processing. They’re ancient foods that can be (and were) gathered by hunter-gatherer societies. In the book Catching Fire: How Cooking Made Us Human, the author cites research showing that humans began cooking meats and tubers hundreds of thousands of years ago. It was these calorically-dense foods, easily digested after cooking, that allowed our big brains to develop.
So when we talk about Paleo Man with his tall stature and good bones and teeth, we’re talking about a man who gathered and ate some roots, tubers and other starchy plants to go along with his meat and fish. My Irish ancestors didn’t eat rice or yams or plantains, but that’s not the point (or so I realize now). Because the truth is, none of us eats exactly what our paleo ancestors ate. We can’t. They hunted animals that have gone extinct. They gathered plants that have mutated or gone extinct. When we shift towards what we now call a paleo diet, the best we can do is try to eat foods that provide the nutrients they consumed, not the same plants and animals that provided them with those nutrients. My Irish ancestors didn’t eat yams, but they likely discovered species of edible roots and tubers while digging up the Guinness bushes to make themselves a yummy drink.
With all that in mind, I added small servings of sweet potatoes and squashes back into my diet, but considered them an acceptable real-food treat, not a necessary part of a healthy diet. I figured I could just easily live without any starchy foods, and perhaps I can … but perhaps some people can’t, and perhaps I’m better off with those foods than without them.
As you know if you saw my most recent speech, I’m a fan of the Wisdom of Crowds effect: when people communicate what they know with each other, the answers bubble up. In the cyberspace crowd of health-oriented blogs and Facebook groups, I noticed more and more people saying they developed problems on a strict very-low-carb diet – low thyroid function, cold hands and feet, high fasting glucose, dry eyes, etc. – which went away when they added some “safe starches” back into their diets as prescribed in the Perfect Health Diet. In the same post about safe starches where I made the wisecrack about my Irish ancestors, in fact, Chris Kresser made this observation:
I see a fair number of patients in my practice struggling with symptoms like hair loss, cold hands and feet, plateaued weight loss, low energy and mood imbalances after following a VLC diet for several months. In many cases they adopted this approach to lose weight, which was successful – at least to a certain point. However, others were not overweight to begin with and simply chose to eat VLC because they got the impression that “carbs are bad”, even for people without metabolic problems. I believe many of these issues are related to the decrease in thyroid hormone levels seen on VLC diets.
In cases where there is no significant metabolic damage, when I have these folks increase their carbohydrate intake (with starch like tubers and white rice, and fruit) to closer to 150g a day, they almost always feel better. Their hair loss stops, their body temperature increases and their mood and energy improves.
So I figured there had to be something to it. Kresser is a brilliant guy and treats a lot of patients. That’s real-world experience talking. But he followed with this:
For people that are overweight and are insulin/leptin resistant, it’s a bit trickier. In some cases increasing carbohydrate intake moderately, to approximately 100g per day, actually re-starts the weight loss again. In other cases, any increase in carbohydrate intake – in any form – will cause weight gain and other unpleasant symptoms. A different approach is required for these patients.
As always, there’s no simple answer and no one-size-fits-all approach. If I could leave your readers with one point, that would be it.
I agree completely. We’re all different. Some people may need starchy carbs in their diets, other people probably don’t. Until recently, I put myself in the second camp. I was doing fine without making safe starches a part of my daily diet. I never developed any of the health problems people were saying they cured with safe starches. Cold hands and feet? Nope. Dry eyes? Nope. Depressed thyroid? Not according to the battery of lab tests I had when I turned 55. So I figured if it ain’t broke, don’t fix it, and continued pretty much ignoring the safe-starch issue.
It was revisiting resistant starch that finally prompted me to revisit safe starches and read Paul Jaminet’s book. Why? Well, it’s all about gut health and the microbiome. After Richard Nikoley beat me and thousands of other people over the head with a hundred or so posts on resistant starch, I decided to give it try. Within two days, it solved the one issue I had not just with a low-carb diet, but with every diet I’ve ever tried: slow digestion. As I’ve mentioned in several posts, the worst digestion I ever had was back in my grain-eating vegetarian days. I always had a bottle of Pepto-Bismal in my medicine cabinet and packed the chewable version when I traveled. Going low-carb cured that. No more stomach aches, no more irritable bowel, no more gastric reflux – probably because going low-carb meant giving up wheat and other gluten-containing grains.
But the slow digestion stuck around, so I either ate good-sized servings of almonds or swallowed psyllium-husk pills before bed. That usually did the trick. But after starting a protocol of resistant starch and probiotics, my digestion has been excellent – better than it’s ever been. I’m also sleeping more deeply than I have in decades, which is quite a welcome development, since I’ve been prone to occasional bouts of insomnia for most of my life. I feel clear-headed and alert soon after waking. Normally it takes two big cups of coffee before I feel truly awake.
That’s when I decided my if it ain’t broke, don’t fix it confidence was misplaced. Something was broken, or at least far from optimal. My version of a near-paleo diet was controlling my blood sugar and keeping my weight down, but it wasn’t properly feeding my gut bacteria.
In an email exchange with Richard Nikoley, he told me he first learned about the benefits of resistant starch from Tim Steele. In an email exchange with Tim Steele, he told me he first learned about the benefits of resistant starch from … wait for it … Paul Jaminet. Okay, I thought to myself, it’s about time I read this guy’s book.
And so, with apologies to Jaminet for the longest preamble ever to a book review (and for that wisecrack about my Irish ancestors), I’ll explain why I believe it’s one of the best books on nutrition I’ve ever read.
In case you’re not familiar with his story, Paul Jaminet lived on a standard American diet for decades and paid for it with ill health. His health improved on a very-low-carb paleo diet for awhile, but then he developed other problems – scurvy, to name one example. So his low-carb paleo diet was better, but obviously still not good enough. It was the desire to find a perfect diet that inspired all the research that eventually went into the first edition of the Perfect Health Diet book and the Perfect Health Diet website.
Among other careers, Paul Jaminet was once an astrophysicist at the Harvard Smithsonian Center for Astrophysics. His wife and co-author, Shou-Ching Jaminet, is a molecular biologist and cancer researcher at the Harvard Medical School. So let’s just say they’re on the smart side of the bell curve and not afraid to delve into the heavy-duty science stuff. Fortunately for the book’s readers, they explain it clearly. In fact, I would describe their writing style as relentlessly logical – and I mean that as a compliment.
The relentless logic that underlies the Perfect Health Diet goes like this: ill health is the result of pathogens, nutrient deficiencies and toxins. So other than avoiding pathogens, the key to robust health is a diet that excludes toxins as much as possible while providing the optimal intake of all necessary nutrients. Optimal intake means enough to derive the biological benefits, but not enough to become toxic – because almost anything can become toxic to humans at some level. Not too little, not too much.
Among many other nutrients, the Jaminets make a case that there’s an optimal intake of glucose – otherwise known as starch. (Fruits provide most of their calories as fructose, and sugar is roughly half fructose and half glucose.) As the book explains:
For glucose, as for all other nutrients, our strategy is to find the peak health range – the intakes at which benefits have ended and there is still no toxicity.
That peak health range is the amount of glucose our bodies require on a daily basis — somewhere in the range of 100 to 150 grams. It’s this chapter of the book that started all the hubbub over “safe starches.” Yes, your body will convert protein into glucose – even if it has to raid the protein stored in your muscles to do so – but the Jaminets argue that forcing your body to meet its daily glucose requirement through gluconeogenesis can eventually cause the health problems Chris Kresser described seeing in some of his patients: slow thyroid, dry eyes, cold hands and feet, low energy, weight-loss stalls, etc.
I don’t believe everyone on a very-low-carb diet will develop those problems, of course. I didn’t. But as I mentioned above, I’ve been including occasional servings of sweet potatoes and squashes in my diet for awhile now, plus I usually consume a high-carb Mexican meal on Saturday night. Perhaps that made the difference. Or it could just be that some of us are more efficient at producing glucose from protein than others and therefore avoid the glucose-deficiency problems the Jaminets describe.
The point is, just because a low-carb diet is beneficial for many people, it doesn’t mean a no-carb diet is even better. If the optimal intake for most people is somewhere in the 100 to 150 gram range, which the Jaminets believe it is, then we need to obtain those carbohydrates from foods that also provide nutrients without tossing toxins into the mix. That’s the logic behind what they call safe starches: potatoes, sweet potatoes, taro, tapioca, white rice, plantains, yams and sago. Those are low-toxin Paleolithic foods (with the possible exception of rice) that provide nutrients such as potassium, copper, vitamin A, resistant starch and fiber.
The Jaminets mention resistant starch specifically several times in the book. Here’s an example from a section about the benefits of producing butyrate in the colon:
Although the fiber in cereal bran is harmful, two kinds of fiber seem to be highly beneficial: resistant starch and pectin. These also happen to be the types that generate the most butyrate.
“Resistant starch” is starch that is indigestible to human digestive enzymes. Potatoes naturally come with high levels of resistant starch. But all starchy foods can form resistant starch after cooking and cooling. Cooking gelatinizes starch into a form that is readily digested by human amylase, but if it is allowed to cool, some of this gelatinized starch re-forms into resistant starch.
In a later chapter on meal planning, the Jaminets mention that they regularly cook several potatoes ahead of time and then store them in the refrigerator (a habit Chareva recently adopted as well). That means a good chunk of their safe starch is also resistant starch, the kind that keeps our gut bugs fat and happy.
The Perfect Health Diet is not an invitation to go carb-crazy – not by a long shot. The book specifically says starches should only be eaten as part of meal that includes plenty of fat to avoid glucose spikes. Despite being dismissed or ignored by much of the low-carb world (including yours truly) because of the safe-starch issue, the Jaminets are essentially advocating a lowish-carb paleo diet. It’s just not very-low-carb. If you followed their advice and were at the lower end of the recommended starch intake, your diet would be roughly 20% carbohydrate, 15% protein and 65% fat. Is that high-fat enough for you?
My Fat Head fast-food diet was 22% carbohydrate, by the way, with a lower proportion of fat (55%) than the Jaminets recommend. Funny how I became known as a “fat head” low-carb advocate while the Jaminets didn’t, at least not in low-carb circles. Of course, my 100 grams or so of starch were coming from hamburger buns and potatoes fried in vegetable oils, both of which the Jaminets advise against. I guess we could call my experiment The Very Imperfect Health Diet.
So far I’ve been focusing on the safe-starch aspect of the Perfect Health Diet, since that’s the section that caused all the debate in the paleo and low-carb diet worlds. But there’s way more to it than that. The new paperback edition runs just over 400 pages and offers advice on the optimal levels and best sources for all three macronutrients and plenty of micronutrients. The first chapter is titled Why We Start with an Evolutionary Perspective, so not surprisingly, almost everything in the book will have paleo enthusiasts nodding their heads in agreement. (Mark Sisson wrote the forward for this edition.)
The chapter on grains is titled The Most Toxic Food: Cereal Grains. (It’s like a Reader’s Digest version of Wheat Belly. They could have titled it Wheat Is Murder.) The chapter on vegetable oils is titled Liquid Devils: Vegetable Seed Oils. Sugar takes a beating in a chapter titled The Sweet Toxin: Fructose. (Dr. Robert Lustig would approve.)
There’s a ton of good information in the book, but since this will already be a long post, I’ll just give you a taste with some random quotes in no particular order:
Don’t be afraid to eat fat! Hunter-gatherers flourished on a fat-rich diet.
Too often, experts dole out advice based on unproven hypotheses without ever looking at the scientific evidence from evolutionary selection. In fact, evolution selected for a certain salt intake. Anti-salt advice was not supported by reliable studies.
One often hears that glucose is the body’s primary fuel. That is quite mistaken. It’s true that all human cells can, if need be, metabolize glucose. But mitochondria, the energy producers in most human cells, prefer to burn fat. So in the body, fat is the preferred and primary fuel, except in specialist cells that lack mitochondria or ready access to fat.
Saturated and monounsaturated fats are the safest calorie source – indeed the only calorie source that is nontoxic even in very high doses – and should provide the bulk of calories. Fish, shellfish, beef, lamb, and dairy fats such as butter and cream are the best animal sources; coconut milk and coconut oil are great plant sources.
Saturated fat improves lipid profiles in two ways: it increases levels of protective HDL cholesterol, and it makes LDL particles larger and more buoyant, protecting them from glycation and oxidation.
Choline is abundant in liver and egg yolks — foods American eat less than ever before, thanks in part to the demonization of cholesterol… Get choline by eating three eggs yolks a day and liver once a week.
As our Paleolithic ancestors who dominated the globe were characterized by tall stature and healthy teeth and bones and their health deteriorated as soon as their diet was altered, we think it’s safe to say that such a low-carb, high-plant, starch-meat-and-fat-based diet is a healthful human diet.
When the obese try to eat less on a malnourishing diet, they sooner or later become hungry and weight loss stalls or reverses.
The long-term effects of eating less without improving the character of the diet are shockingly bad… efforts to eat less often lead to weighing more.
In their own version of what I’ve termed Character vs. Chemistry in several posts, the Jaminets explain that hunger is the body’s way of saying I need nutrients! If your diet is deficient in a necessary nutrient, you’re going to be hungry, and eventually you’re going to give in and eat more. Nutrient deficiencies, in fact, may explain why people adopt a particular diet, feel great for awhile, then feel not-so-great, adopt a different diet, feel great for awhile, then feel not-so-great, lather, rinse, repeat. To quote from the book:
Sometimes people alternate among extreme diets. They do a low-fat diet, and it works great until a fat-associated nutrient becomes scare and hunger returns. Weight starts to rebound due to hunger for the fat-associated nutrient. Disturbed by the weight gain, they shift to the opposite diet – low-carb, high-protein, high-fat. Now weight loss resumes until they become deficient in some plant-associated nutrient that, on their low-carb diet, they no longer obtain. Then weight loss stops, hunger increases, and the weight comes back.
The key to long-term weight loss, then, is a diet that provides all the necessary nutrients without an overabundance of food. When you give your body what it needs, it stops ramping up your appetite in hopes that you’ll keep eating and eventually stumble across some actual nutrients.
Darned if that doesn’t make perfect sense. That’s what I kept thinking to myself as I read the book: Man, this is all so logical. It just makes sense.
Like I said, the Jaminets are relentlessly logical. Their own health problems inspired them to undertake a seven-year, relentlessly logical review of the science and design a diet based on unprocessed whole foods, high in fat and low in carbohydrates … but not low enough to create a deficiency that could cause other problems, and with the carbohydrates coming from real foods that provide real nutrients, such as resistant starch to feed our gut bacteria.
Is the Perfect Health Diet truly the perfect diet? I don’t know, but I was persuaded to move my own diet more in that direction. I’ll describe what that looks like in a future post.
Meanwhile, I asked Paul Jaminet if he’d be up for a Q & A with the Fat Head audience, and he graciously agreed. Ask your questions in the comments section for this post. Put the phrase “Question for Paul Jaminet” at the beginning of the comment so I know it’s a question for him, not for me. I won’t reply to those comments. I’ll pick a dozen or so questions and forward them to Paul, then post his answers.
Perhaps you’ll be persuaded to eat a potato smothered in grass-fed butter.