Starch: Pure Evil or Evolutionary Gold?

Would eating starch improve your health? Or should we avoid it like the plague? Let’s take a look at this starch paradox and see if it’s a group of foods that might help your health.

A traditional Inuit family eats a day’s worth of food consisting of raw and cooked seafood and fermented foods. Basically, they ate a 0% starch diet and most of their calories came from fat. But they are famous for their lack of chronic diseases like tooth decay, heart attacks, cancer and diabetes. So, that must mean that carbohydrate is unnecessary for good health and might actually be one of the reasons our western populations are so sick right?

Well, let’s take a peek at the meals of a Tukisenta family. The majority of the meal is carbohydrate, mostly starch from sweet potatoes. At an average of 94.6% carbohydrate, it would appear they follow the opposite approach of the Inuit. And yet they have great health, too. This group of people destroys the simple argument that carbohydrate from starch are inherently bad or disease causing.

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So what should we make of this starch paradox?

I simply think context is everything. When it comes to real food, the idea of “good” or “bad” is mostly argumentative trickery as the context is what really matters.

The reality is just like cortisol and LDL cholesterol are not inherently “bad” in the body, neither are real foods like potatoes and other forms of starch. As many readers of this blog know, there is a definite subset of people who CANNOT handle starch. I’m going to explore the contextual issues that actually matter in the starch debate.

What is Starch & Where Can You Find It?

Starch is a polysaccharide and specifically forbidden on the Specific Carbohydrate Diet. Starch is a chain of glucose molecules that, depending on the arrangement, can be further characterized into amylose and amylopectin. Amylose is important to note because it’s harder to digest than amylopectin. Due to its structure amylose is called a resistant starch, which means it ends up being valuable as a prebiotic.

In other words, starch is a complex arrangement of glucose molecules and depending on where the bonds are we call it amylose or amylopectin.

Starch is considered the most abundant carbohydrate source in the human diet. Starch is predominately found in three classes of foods:

– Grains & seeds – Wheat, Corn, Rice, Barley, Millet, Oats, Rye

– Root Vegetables – Sweet Potatoes, Potatoes, Taro, Yuca, Parsnip, Turnip

– Legumes – Lentils, Fava beans, Peas, Mung beans, Chickpeas

** this list is not all inclusive **

Starch is really just a bunch of glucose molecules bonded together,  found in most every plant on earth at various times during the growing cycles.

Are All Humans Capable of Eating Starch?

What a fundamental question, yet I hadn’t ever thought to ask it. Luckily, Chris Masterjohn was all over it at AHS 12. As Chris’s presentation shows, humans need to use the enzyme salivary amylase to digest starch. Chris presented studies that showed humans have more copies of the amylase gene AMY1 compared to our nearest ape relatives. And that even in populations who historically eat a low starch diet, they still had several copies of the AMY1 gene.

Chris’s data suggests the more copies of the AMY1 gene a human has, the better they seem to be able to digest starch. This is most likely from an ability to produce more salivary amylase in the mouth. Honestly, the best thing to do is watch the first 8 minutes of this video:

Chris Masterjohn — Oxidative Stress & Carbohydrate Intolerance: An Ancestral Perspective from Ancestral Health Society on Vimeo.

In summary, even if your ancestors didn’t hail from a population who typically ate large amounts of starch, it is likely you evolved to have multiple copies of the AMY1 gene. And these multiple copies should allow you to produce plenty of salivary amylase to digest starch.

How Exactly is Starch Digested?

Starch digestion starts in the mouth with the enzyme salivary amylase. As soon as we start chewing starch, salivary amylase kicks into gear and starts to break down some of the starch into maltose. Maltose is a disaccharide and will require further enzymatic action in order to be split into the monosaccharide glucose, which the body absorbs in the small intestine.

After we swallow the starch and it heads to the stomach, some of the starch will be maltose, but the majority will still need to be broken down. Some of the salivary amylase will still be working on the starch in the stomach until it becomes deactivated by gastric acid.

As the remaining starch moves from the stomach to the small intestine, pancreatic amylase will further break the starch into maltose. At this point, all the maltose will need to be broken down into glucose in order to be absorbed. This happens via a brush border enzyme called maltase, which comes from the villi and microvilli.

Starch digestion is actually more complex than one might imagine. And with so many steps there are plenty of places for problems. Not to mention, as Chris Masterjohn said in his presentation, it appears some of us won the AMY1 genetic lottery and seem to handle starch digestion better than others.

Who Might Want to Eat Starch…

Let’s talk about who might be great candidates to eat starch. People who might consider eating regular starch are those who choose lifestyles that are filled with lots of high aerobic activity. Who are these people?

  • Those spending 5+ hours a week “working out”
  • Cross fitters / high-intensity exercise
  • Endurance athletes
  • Competitive athletes of all types

In other words, these people place high demands on their body on a near daily basis. Robb Wolf has written a great summary of why extra carbohydrates can be very beneficial for these people. Read this series starting with part 1, part 2 and part 3.

Anyone else who doesn’t have one of the problems listed below is a great candidate to give starch a shot and see how it treats them. We all theoretically have the ability to digest it and plenty of groups of people subsist on various levels of starch. I think the key here is to eat the root vegetable forms of starch and not those that include toxins like grains.

Who’s at Risk for Starch Attack!

Just as people who have celiac disease shouldn’t eat wheat, and those with hereditary hemochromatosis should avoid foods high in iron, there are certain groups of people for which starch will not be a good idea.

Insulin Resistant – Diabetics 1 & 2 / Pre-diabetics – Contrary to what the conventional doctors tell diabetics, carbohydrates and starches are toxic to those who have blood sugar control issues. Part of this might be genetic, but in general it’s a really good idea to do some at home testing with a blood glucometer. The fact is if you don’t have good blood sugar control then you need to avoid putting stress on a broken system and eat a low carbohydrate diet.

Small Intestinal Bacterial Overgrowth (SIBO) – Why isn’t starch allowed on SCD? Because SCD is designed to treat those with gut dysbiosis like SIBO. In those with SIBO, bacteria has inappropriately overgrown in the small intestine, and easily feeds on unabsorbed starch and other disaccharides. The digestion of starch is complex enough, that if you have a few mistakes in the process, the small intestine could be overloaded with undigested starch. This creates the conditions for all kinds of bacterial issues just like blood in the water for sharks. It’s not uncommon for these people to not be able to tolerate even a bite of starchy food.

Candida Overgrowth– Candida albicans or any other yeast overgrowth in the gut is a common issue for those dealing with chronic digestive issues. It usually occurs in the small intestine but could also be a body wide overgrowth.  Regardless, Candida predominantly feeds on carbohydrates and so all of the same issues that are present for those with SIBO are problems for those with Candida overgrowth.

Celiac Disease – The last step in starch digestion uses the brush border enzyme maltase to break down the disaccharide maltose into the monosaccharide glucose. At this point the body readily absorbs the glucose. These brush border enzymes are secreted from the small intestinal cells located on the villi. Anyone who has active Celiac disease, by definition, will have sections of partially or completely destroyed (atrophied) villi. This makes it almost impossible for the starch digestive process to happen correctly, making it a good idea for all Celiacs to try not eating starch.

Make sure to read Robb Wolf’s low carbohydrate series above, because those who have Neurodegenerative diseases like Parkinson’s and Alzheimer’s seem to do well avoiding carbohydrates. And certain types of cancers (breast, colon, prostate and some brain tumors) appear to respond very well to very low carbohydrate diets.

But if you don’t have any of these issues, how could you test to see if starch is a good idea?

How to Eat Starch and Check for Problems

Don’t assume starch is perfect for you if you don’t have any of the issues above. Unless you’ve tested it you really don’t know.

We’ve always said that everyone has a custom diet, and part of that is testing whether or not starch is beneficial to your health. Now, whenever you introduce any variable into your diet, you should keep everything else very steady to see if you notice any issues. So, that means don’t try eating out this week or a bunch of new foods in the same week that you test starch. Give it a solid test by keeping the variables as fixed as possible.

Remember that every “type” of starch is its own food. And you might do just fine with sweet potatoes, but not rice. Each type of starch containing food needs to be evaluated.

Here’s an example of how to introduce a safe starch into your diet. Use a food journal and record what you’re eating and how you felt.

Day 1 – 1/2 cup of mashed sweet potato

Day 2 – 1/2 cup of mashed sweet potato at lunch and 1/2 cup at dinner

Day 3 – 1 cup at lunch and 1 cup at dinner

Day 4 – 1 cup with butter and cinnamon at lunch and dinner

If blood sugar issues run in your family, you’re overweight, or you believe you might have some blood sugar control problems, it would be wise to use a blood glucometer to check your post-meal glucose readings to see how your blood sugar responded.

You might not suffer any digestive problems but your blood sugar could spike out of control. If this happens your body is not ready for that type of increased carbohydrate in your diet.

What are “Safe Starches” to Eat

Context is everything when it comes to health and wellness. Each person has a custom optimal diet that is influenced by their genes, epigenetics, lifestyle choices and current health. Starch, for many, is a non-toxic and well tolerated source of nutrition. But for a growing number of people who have blood sugar regulation issues and digestive problems it is best not eaten until these health challenges are overcome. The best answer for almost everyone is to test it.

I think it’s pretty clear from the many populations who eat a large portion of starch each day that it’s quite possible for starchy foods to be part of a health promoting diet. I think the case for starch becomes even more compelling when you trim the foods that contain it to those that are low in toxins and potential inflammatory agents.

This list is being called the “safe starches.” These include the root vegetables like sweet potatoes, potatoes, yuca, taro, parsnips, plantains and white rice.

Tell me about your experience with starch in the comments below.


Steven Wright

About Steven Wright

Steve Wright is a health engineer and author. In 2009, he reached a breaking point when IBS took over his life and the doctors didn't know how to help. Since then, he has transformed his health and started to help others naturally heal stomach problems. You can check out his story here and find him on Google+, Facebook or Twitter.

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39 thoughts on “Starch: Pure Evil or Evolutionary Gold?

  1. Avatar

    Why is it that starchy vegetables (with starch that breaks down into glucose) is preferable over fruit sources that are mostly just the simple sugars? Or how about dextrose itself? Seems like in theory dextrose powder should be completely fine on the SCD and cause the least strain on the GI tract since it doesn’t have to be broken down.

    My experience on the SCD was good, but I found the same issue if I added a lot of honey or a lot of fruit or a lot of dextrose….each caused my BMs to go from 4s to 5+ on the bristol stool chart. I never experimented with potatoes or any starches as I figured they were forbidden or only allowed when I was feeling great again.

    • Avatar

      Hi David – the SCD diet aims to eliminate complex carboydrates, as they are harder to digest and break down and therefore can become food for potentially pathogenic bacteria. Thus, simple sugars are easier to digest and are allowed. I hope that helps!

  2. Avatar

    Maybe Mariel can help. I am 37 years old, I have Crohn’s disease of the ileum. I have been thinking of adding brown rice or sweet potato back into my diet. I have been SCD compliant for 4 months. In that time, I have lost 30 pounds. A bit too much.
    I feel so much better, except my last 2 menstrual cycles have come early(like, 12 days) and are extremely light. My normal periods have been 25-30 day cycles and 5-7 days long all my life.
    And this is causing me added stress, wondering if I am harming my body. Am I not getting enough calories, fat, carbs? What?
    Can you help me at all?

    • Avatar

      HI Misty! Your body is going through a ton of changes and the fact that you’re still having a period is good news:) Testing out some starch is totally fine and jst continue to see how your body reacts with it. Calories can play a large role in whether or not our hormones are working correctly, so try adding in some more healthy fat like coconut oil and avocados as well.

  3. Avatar

    Hello ,

    I have been on scd for 7 months to help come off a horrible flare of UC.. Despite lingering symptoms I feel much better. I am wondering if green banana flour is a safe starch I can test ? I really want to try and make some baked goods or protein bars for when I’m on the go . Than you 🙂

    • Avatar

      Hi Domenic – we encourage you to give it a try (as well as other safe starches mentioned in this article) now that you’re feeling good. We can’t promise it will or won’t work for you – the only way to find out is to test it out!

  4. Avatar

    I’ve been following you guys for a few years since my UC flared up after the birth of my son. Prior to that I only ever had one flare then went into remission for 10 years. Three years ago I started scd. It helped me see quick results but I have not been 100% since. I would cheat a bit then try experimenting with other diets, paleo, gaps, fodmaps, but always came back to scd. Now I am 17 weeks pregnant and although I flared in my first trimester, I am quite symptom free for now. My trouble is I am so hungry and have an aversion to meat so I’ve been eating a good amount of rice and in the last two days pizza with a tapioca crust. I’m not sure how well I would have tolerated these before pregnancy since I barely ate them. I haven’t noticed an increase in symptoms but am concerned that is attributed to the fact I am pregnant. I don’t want to indulge while I’m pregnant then have the flare of all flares after birth. How do I take precaution while I’m pregnant but still satisfy my cravings for carbs? Thanks in advance for any insight.

    • Avatar

      Hi Belle, thanks for reaching out to us 🙂

      It is important to eat enough when you’re pregnant and we encourage you to listen o your body and talk with your doctor about this as well.

      In general, we think the safest starches to increase are white and sweet potatoes, plantains (my favorite!!) starchy veggies like carrots and squash, tapioca, and even beans if you soak them before cooking.

  5. Avatar

    I really appreciate you guys looking at diet for treating gut issues as something that should to be customized for each individual body and not a matter of just “illegal” and “legal”. It scares me some, because I’ve read so much about how “cheating” on SCD etc leads to failure to ever recover… Which is why I have strictly followed SCD even as a strict lacto vegetarian for 2.5 months now (I’ve been totally meatless for 15+ years), despite losing energy and muscle and having people who love me tell me they’re worried I’m becoming malnourished etc (although one interesting note is that I’ve lost no weight).

    I’ve already read (I think) all your views on vegetarianism on previous posts, but my question is could an active, strict vegetarian be a candidate for the “need more starches” category?

    I’ve viewed the carb issue as a lose-lose. I either deprive myself, hoping to get better eventually but losing strength and possibly creating long-term issues (because I’m not sure but I’d think a diet that restrictive forever would not be good, plus SCD is supposed to be followed for a significant amount of time) or I eat carbs and never actually get better.

    PS if you have any resources for someone in my situation(ie strict, committed vegetarian), I’d be so grateful (btw I’m dealing with leaky gut, ibs-d, chronic fatigue syndrome, fibromyalgia, what I believe is SIBO, and what mainstream doctors suspect is IBD but I’ve avoided colonoscopies).

    thanks so much.

    • Avatar

      Hi Eruba – thanks for taking the time to comment.

      We think starches have a lot of benefits for many people and we think you should eat the widest variety of foods you can that promote health for YOU.

      If you email us at we can give you all our resources for vegetarians

      Eating enough is critical for success on SCD no matter what. We recommend tracing your calories to be sure you’re eating enough now as you continue experimenting with adding in more new foods.

      • Avatar

        I SO appreciate your response! As I mentioned, I’ve read so much about how “even cheating slightly” on SCD can mean never healing and having to start the diet completely over for any hope of success. So I find this view very refreshing and hopeful to know that I can possibly customize this to work for me and still heal — using it more as a guide and less as dogma. I hope more people start looking into this and share.
        Anyway, I’ve sent you an email. Thanks so much again.

  6. Avatar

    It will be interesting in the next few years to see how funny all this speculation will prove to be about what humans were programmed to eat. All the new research on bacteria over growth and lack of bacteria in the gut is pointing to the fact that somewhere along the way be it over use of antibiotics, GMO eating away at us or just a plain bad diet to full of sugar and processed foods has somehow offset the balance of our bacteria in our bodies and we can no longer digest certain foods. It will be exciting to watch as science is able to pinpoint the little bugs in a healthy gut to be able to replace them in compromised ones. It all comes down to common sense, we were not too long ago able to eat these foods and thrive , ( I am implying a moderate healthy diet with a good balance) let us figure what has caused the change. Remember the writer of the book just gave her opinion as to why a carbohydrate free diet was working, she may have been correct and we will hopefully have an answer soon.

  7. Avatar

    I suffer from gluten and lactose intolerances so I restrict my diet to gluten free and lactose free foods. I am currently trying a FODMAPS elimination diet under the supervision of a nutritionist. I have also reduced my carbohydrate and grain intake. My. intolerance manifests as a severe itchy skin rash or dermatitis. However my stools are generally very healthy and regular. Do you think my intestinal gut and the vili are affected or damaged by the gluten intolerance? I do not wish to have an endoscopy which I am told is the best way to determine Celiac disease.

  8. Avatar

    “So what should we make of this starch paradox?”

    Meal frequency. Here’s a comment I posted on Kresser’s website:

    The Kitavans basically eat one big meal per day. That’s something most people who say that starch/sugars/carbs aren’t a problem because of the Kitavans’ diet carbohydrates % seem to constantly forget. When you eat one big dinner and not much else you can get away with eating pretty much what you want (on that island) and not get fat and sick, especially if your whole lineage going back thousands of years has never been touched by dirty 20th century industrial food products. These people have been on the equivalent of Ori Hofmekler’s Warriot Diet since the beginning of time.

    So you can’t simply look at the Kitavans’ (or any other primtive peoples’) macronutrient ratios and compare those with the breakfast-then-lunch-then-dinner standard North American diet. What’s unhealthy in the long run is eating starch/grains/sugars all day long.

  9. Avatar

    Hey just a question. I’ve had roast potatoes twice this week with no effect. Is this safe to say I can tolerate them?

    Also a few weeks ago I ate bread every day for a week with no symptoms. It was very good quality bread. Just wondering if you think i can tolerate bread also if I went a whole week?

    Thanks so much for this website! Big fan!

    Every blessing,


  10. Avatar

    Hi Steven,

    My GI used the hydrogen breath test and diagnosed me with SIBO a couple years ago. I stayed away from safe starches but I recently started eating safe starches (sweet potato and plantains) after my workouts. I don’t seem to have digestive issues after consuming these foods. I know you suggested a blood glucometer but would I experience any other symptoms? As far as my digestive issues, I do notice at time I don’t feel like I have a complete elimination and I struggle with my lower abs. I feel like my belly protrudes out but that can be a fitness issue. I just wonder if there could be any other GI issues. My GI also dx me with IBS but that doesn’t say much. Thank so much for your help!

  11. Avatar

    So if you have candida should you avoid low starches like carrot turnips butternut and Beets i thought Scd and Gaps promote the use of safe starches so you do not go really low carb and effect adrenal issues. Scd even mentions red lentils as a safe alternative.
    i guess i am a little confused what do you guys recommend?

  12. Avatar

    when is it best to try sweet potatoes for people with UC? a year? once you get to phase 5? any thoughts would be appreciated as I am a weightlifter and grow and recover better with the inclusion of starch in my diet.

    • Avatar

      I’m wondering this, too, Chris. My son has “mild” indeterminate colitis (presents like Crohn’s). He’s doing great on SCD so far, but he’s going to hit puberty soon, and needs to gain weight. I know we’re not anywhere close to introducing starches (we’ve only been on SCD for a little over a month), but would love to know at what point we can start.

      I’m guessing it’s when you’ve been symptom free for a while. Maybe a year?

  13. Avatar

    I am pretty sure that I have SIBO (I’m actually meeting with a gastro. today who tests for/treats it so I’ll be able to find out for sure), and I know I have a leaky gut (took the Cyrex Array 2 test). I get basketball-sized bloat after eating a lot of things, but oddly enough, safe starches don’t cause it. I have no issues with white rice, sweet potatoes, plantains, yuca or turnips. Is it possible that these starches are still feeding the SIBO even though they don’t cause the immediate reaction of bloating? They also don’t cause any other noticeable GI reactions.

  14. Avatar

    I have been doing an SCD based diet for one year 5 months, but after about 10 months I had to add in more carbs, as my muscles were very weak & I could hardly stand. I believe that was because I wasn’t getting enough glucose for them. Glucose is also needed for the immune system & although SCD helps dysbiosis, it doesn’t really help candida a lot which needs glucose to strengthen the immune system against it. I found that I was eating a lot of fruit & honey, but they have a lot of fructose in & not so much glucose. They were also feeding my candida, along with the starchy vegetables, such as carrots & peas. I couldn’t get on with sweet potatoes or parsnips, so I added in some ordinary potatoes (with skins) & brown basmati rice initially & felt much better & stronger. Now I don’t eat either of those, but eat millet, amaranth & sorghum instead, because they are probably better for candida than potatoes and rice. I certainly feel much better eating more carbs though.

  15. Avatar

    I feel listless and foggy-brained when I don’t eat starches. When I was doing full SCD I felt like I could hardly get out of bed…not good. So, on the advice of my nutritionist, I introduced sweet potatoes and white rice. I felt better. I started eating mung beans, quinoa and barley after seeing an ayurveda practitioner, and boom! Energy power punch…unfortunately, I haven’t figured out how to balance my grain intake so that I don’t end up with a whole lot of extra nervous energy (and extra calories).

    • Avatar

      I had the same problem for years and discovered I was overly restricting carbs. I don’t want to diss this guys diet but I highly suggest looking into the work of Dr. John McDougall. Just put his name in a google or YouTube search bar and you’re set.
      Good luck

  16. Avatar

    I CrossFits and lift weights, I’m in the box about 5-6 days a week, 2 hour sessions. I eat a fairly clean diet. Ive been experiencing erectile dysfunction for the past year or so. My mood and stuff is all good. My testosterone is actually high. I am young. My libidido is close to gone. My lifts have gone up and I feel strong. The only problem is getting and erection and maintaining it. Could carb consumption be beneficial? I consume carbs…but more?! Thanks

  17. Avatar

    I am experimenting with white rice. I tried a strict SCD for 6 month and only saw improvement initially, after that my symptoms stayed the same. I am loosening my dogmatic approach to scd and am experimenting with some starches… white rice seems to be ok so far.

  18. Avatar

    I have been on the SCD for over 2 years now and feeling great. I have introduced potatoes, and very occasionally I eat rice. I’ve had no problems. This is the 2nd time I’m on the SCD. The first time I gradually added more foods until I was eating everything and proceeded to flare. I think the key this time is that I avoid wheat and sugar. I have on rare occasion tried spelt flour with no ill effects. I also take SCD yogurt, probiotics, fish oil, calcium and vitamin D. Avoiding (or handling) stress is also key.

    • Steven Wright

      @Dr Tim – Not familiar with the Fast tract diet but if they are describing fermentation of the starch in the small intestine… SIBO or yeast overgrowth is likely the issue which I stated above those who have these problems should avoid starch. Is that on the same track?

  19. Avatar
    Shahar Geffen says:

    Hi Steven, according to your article, people who have UC will not benefit from the SCD diet.
    I’ve got UC, and on the fourth day of the Intro diet.
    I came off Predisolone four weeks ago, my BM where solid until a week ago when I started seen a bit of blood on the stools (I’m eating only SCD legal food, but didn’t start with the intro), so four days ago I started the intro, and for four days I’m eating ONLY the chicken soup with carrots (your way of doing it).
    The problem is that I don’t have normal and solid stools (I have small mucusie with blood in it), any longer, and I’m going to the toilet more often, and the blood is getting worse.
    If you have any idea to help me, I’ll appreciate it very much.

    • Steven Wright

      @Shahar – This article talks nothing of how well UC people benefit from SCD. I think you need to spend some more time on the site reading all the success stories from people who have UC as they do very well on it. SCD is but one aspect of a treatment plan. Those coming off prednisone (an extremely powerful drug) typically need adrenal support and other supplements in addition to SCD.

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