In the conventional world, whole grains and legumes are viewed as universally beneficial. In the Paleo world, they’re viewed as inflammatory foods that should be avoided by everyone. Who is right? That’s the question I cover in this week’s podcast. It turns out that the answer isn’t as simple as dogma on either side of the debate suggests.
In this episode we discuss:
- Should we avoid foods with lectins?
- Should we avoid foods with phytic acid?
- Reasons why you should limit or avoid legumes and grains
- Customize your diet to meet your individual tolerance
- New book coming soon
Chris Kresser: Hey, everybody, it’s Chris Kresser. Welcome to another episode of Revolution Health Radio. This week we have a question from Staci. Let’s give it a listen.
Staci: Hello my name is Staci. Thank you so much, Chris for all you do. I absolutely love your website and your podcast. I use it as a resource for myself and for my patients. I’d like to ask a question that I really tried to research very hard and I’ve had trouble because most of the research on whole grains compares it to the regular SAD diet with processed flours, the white stuff, the sugar. So it’s really hard because the evidence will of course say that whole grains are better. But I want to know if outside of food sensitivities, are gluten free, whole grains that are unprocessed, not turned into flours, things like quinoa, rice, brown rice, things that you’re cooking in a pot and eating essentially, are they inflammatory? Are they bad for our microbiome? I haven’t seen evidence to support this. I think that if people have a food sensitivity to it, and for sure that happens especially with IBD and other autoimmune conditions, it’s very common to have food sensitivities even to gluten free whole grains. But outside of having a food sensitivity to it, is there evidence that everyone should be off of gluten free, whole unprocessed grains? I haven’t been able to see that. Is it true that they’re inflammatory for those that don’t have an immune reaction because it’s a food sensitivity for them? Is it true that they’re not good for the microbiome? The research that I’ve seen shows that it improves biodiversity, the microbiome, whole grains. So that would be what I’d like to ask you today. If anyone can help me with this question, I think it could be you. You do mention that the Paleo is the template. And I think that that might be part of the answer. It’s a good place to start, but not necessarily everyone needs to be off of them — off of whole grains or legumes or things like that. Especially if they’re prepared in the right way. So that’s my question for you today. Sorry it’s a little long-winded. Thank you.
Chris: Okay, Staci, thanks for sending your question. I’m going to expand on this a little bit and talk about legumes as well as grains because I often get questions about whether legumes can be part of a healthy diet. Of course, the Paleo dogma holds that we should never eat grains or legumes. There are usually two arguments to support this idea. The first is that grains and legumes contain lectins.
Should we avoid foods with lectins?
Lectins are a type of protein that can bind to cell membranes, and animal studies have shown that lectins can impair growth, damage the lining of the intestine, destroy skeletal muscle, and interfere with the function of the pancreas, among other things.
That sounds pretty bad, right? Not so fast, though. There are several reasons that these results probably shouldn’t be extrapolated to humans:
- The first is that animals in these studies consumed an enormous amount of lectins—much more than a human would get from a varied diet that includes some grains and legumes.
- Second, most lectins are destroyed by cooking. For example, cooking legumes for as little as 15 minutes or pressure-cooking them for seven-and-a-half minutes almost completely inactivates the lectins that they contain, leaving no residual lectin activity in properly cooked legumes and grains. The results vary a little bit depending on the legume and the grain, but that’s a general rule. Cooking does inactivate most lectins.
- What’s more, other components in food, like simple sugars, can bind to lectins and diminish their toxic effect. Even if there is a small amount of lectin left after cooking, it’s unlikely that it will have a detrimental effect, given the presence of simple carbohydrates in both legumes and grains that can bind to those proteins.
- Finally, if lectins really are a problem, then we’ll have to cut out a lot more than grains and legumes from our diet if we want to avoid them. Turns out the lectins are present in over 50 different fruits, vegetables, spices, and commonly eaten plants, including carrots, zucchini, melon, grapes, cherries, raspberries, blackberries, garlic, and mushrooms, to name a few.
Every plant we eat contains some small amount of toxin, since this is how plants defend themselves. In the majority of these cases, these low levels of toxins don’t harm us, and in fact they may even provide health benefits. For example, many of the compounds that we call antioxidants, like polyphenols found in blueberries, dark chocolate, etc., are actually pro-oxidants that cause mild oxidative stress, and by doing that they upregulate our body’s natural antioxidant defense system. This is a little-known fact about so-called antioxidants. They actually benefit us by promoting a little bit of oxidative stress that our body then responds to in a hormetic, or favorable, way.
The one lectin we may want to exercise caution with, though, is peanut lectin, since both raw peanuts and peanut oil have really high lectin content. There is some data in animals that suggests that peanut lectin may contribute to atherosclerosis by stimulating the growth of smooth muscle and pulmonary arterial cells. However, other research, including clinical trials in both animals and humans, has found that peanuts and even peanut oil actually reduce cardiovascular risk factors and thus may protect against heart disease. I think the jury’s still out even in that case.
Are grains and legumes really that bad for you?
Should we avoid foods with phytic acid?
The second argument that is typically made against grains and legumes is that they contain phytic acid. Phytic acid is the stored form of phosphorus that is found in many plants, especially in the bran in whole grains, and nuts and seeds. Although herbivores like cows and sheep can digest phytate, or phytic acid, humans cannot. This is bad news because phytic acid binds to minerals, especially iron and zinc, in food and prevents us from absorbing them. It’s important to note that phytic acid does not leach minerals that are already stored in the body; it only inhibits the absorption of minerals from food in which phytic acid is present. If you eat rice or oats that have phytic acid in them, then you don’t absorb as many nutrients as you would otherwise from those foods if the phytic acid was not present, but the phytic acid is not going to remove nutrients that are already stored in the body. Phytate can also interfere with enzymes that we need to digest our food, including pepsin, which is needed for the breakdown of proteins in the stomach, and amylase, which is required for the breakdown of starch. Phytic acid also inhibits the enzyme trypsin, which is needed for protein digestion in the small intestine.
Again, at first glance it sounds pretty bad, right? It sounds like we shouldn’t be eating any phytic acid at all. While it’s true that diets that are high in phytate contribute to mineral deficiencies, it is also true that humans can tolerate moderate amounts of it without harm. This might be because our gut bacteria produce enzymes that break down phytate and thus make us able to extract the nutrients that the body needs. In fact, there is even some evidence that phytic acid has beneficial effects. It has been shown to prevent the formation of free radicals, which makes it an antioxidant; it prevents the accumulation of heavy metals in the body and plays a role in cellular communication.
The problem with telling people to strictly avoid grains and legumes because they contain phytate is that, just like legumes, many other healthy foods in the diet, including Paleo-friendly foods, contain substantially higher amounts of phytic acid than legumes or grains. For example, a single serving of trail mix, which is that beloved Paleo snack favorite, is likely to be much higher in phytic acid than a serving of lentils or whole grains. Cacao beans, which we make chocolate from, have about the same amount of phytic acid as most other beans and legumes, and spinach and Swiss chard are higher in phytate than almost any legume, nut or seed.
It’s also important to note that phytic acid can often be at least partly broken down by certain food-processing methods, such as soaking and roasting. I wrote an article awhile back called “Another Reason You Shouldn’t Go Nuts on Nuts,” suggesting that you can dehydrate roasted nuts before eating them for exactly this reason. In the case of legumes, studies have shown that soaking at room temperature for 18 hours or at 140 degrees Fahrenheit for three hours eliminates between 30 and 70 percent of phytic acid, depending on the legume. For grains, it really varies, depending on the grain. Some grains have phytase, which is the enzyme that breaks down phytic acid, naturally present in the grain, and so those grains typically don’t need to be soaked for as long. Whereas other grains don’t have phytase and need to be soaked for longer, and generally it’s better to add some kind of acidic medium like fermented dairy, kefir, lemon juice, or something like that to the soaking water to help activate the enzymatic process.
Some of you might be familiar with the Weston A. Price approach to eating. It’s basically a Paleo diet that also includes properly prepared grains and legumes. For example, if you’re going to eat oatmeal, you would soak the oats overnight in room-temperature water with maybe a little bit of kefir, and then you would drain that in the morning and then you would cook those soaked oats. Same if you eat brown rice or if you eat lentils or other legumes, you would soak them and prepare them properly.
This is in fact what all traditional cultures who consumed whole grains and legumes did. Whether you’re talking about indigenous people in what is now Mexico or Central America, they did that with corn and cornmeal. People who lived in Africa who consumed various grains and legumes and people all over the world who Weston Price studied. People in what is now Switzerland, they made a natural sourdough bread, which is a fermentation process, of course, that would break down the phytic acid and make the nutrients more bioavailable. This is a common practice in any culture that traditionally ate whole grains and legumes. The problem is, today almost nobody does that except people who are aware of the importance of this or maybe even some traditional cultures … people living in the industrialized world who maintain some connection with their traditional ways.
Reasons why you should limit or avoid legumes and grains
Given everything that we’ve talked about so far, you might think I’m a fan of whole grains and legumes, but there are several reasons why I think many people may need to limit their consumption of these foods and why I still do recommend a Paleo template as the best starting place for most people.
The first reason comes down to nutrient density and optimizing this, the amount of nutrients that we consume in our diet on a day-to-day basis, should be one of the main goals that we have comes to food. Micronutrients are the fuel for our bodies, and suboptimal amounts of any of them will cause significant problems. Nutrient deficiency is just widespread in the industrialized world. More than a third of Americans are deficient in essential nutrients, and that’s using the RDA, our recommended dietary allowance, which is the threshold at which acute deficiency symptoms occur. That doesn’t mean that the RDA is the optimal intake level of a nutrient; it’s just a level at which we start to see very acute symptoms of deficiency. If we used instead the optimal intake of a given nutrient, the number or the percentage of Americans and other people living in both the developed and developing worlds that are deficient in nutrients would be much higher.
The most nutrient-dense foods are organ meats, shellfish, spices and herbs, meat and fish, nuts and seeds, and fruits and vegetables. I shared some references to these nutrient density studies in my first book, Your Personal Paleo Code, which was later published as The Paleo Cure. If you’ve read that book, you’ve probably seen some of this research. Of course, those foods should sound familiar because they make up what we call a Paleo diet or a Paleo template. Whole grains and legumes do contain some nutrients, but they’re generally lower on the list than many of the foods I just mentioned when it comes to nutrient density. Organ meats and shellfish are orders of magnitude higher in terms of nutrient content than grains and legumes, for example.
For that reason alone we shouldn’t base our diets on whole grains and legumes. This of course is one of the reasons why vegetarians and vegans do typically have much higher rates of nutrient deficiency because they consume significantly higher amounts of whole grains and legumes. Often their diet can be based around these foods—and that’s if they’re doing well! There’s of course also the junk food vegetarian who is eating mostly refined flour, sugar, and a whole bunch of stuff that’s not meat or animal products, but it’s not particularly … not only not nutrient dense, but also full of stuff that can be harmful.
There are certain groups that also may need to limit or even completely avoid grains and legumes. One is people with autoimmune disease, which now affects up to one in six Americans. There is some evidence—a lot of it is anecdotal—but there is some evidence suggesting that compounds in these foods, including lectins, may be problematic for people with autoimmune disease. This is also true of other foods like eggs, nightshades, nuts, and seeds, which are proscribed on the autoimmune protocol, or AIP, which I’m sure many people listening to this have heard of and may even be on themselves. I think the evidence for the AIP has been mostly anecdotal so far.
However, there was a peer-reviewed study recently done on at UC San Diego that I’m going to be writing about soon, and that study had actually pretty impressive results that I’m really excited to see. I mean, it’s kind of miraculous that that study got done in the first place because, as I’m sure many of you know, getting funding for a study that’s purely a dietary intervention, when most medical research is funded by pharmaceutical companies, is exceedingly difficult. But what happened is that a gastroenterologist at Scripps down in San Diego was introduced to AIP after witnessing one of her patients with ulcerative colitis, which is an autoimmune disease, made a really astonishing recovery using that diet, and so this GI doc decided to put together a study to formally investigate it both in patients with UC, ulcerative colitis, and also in Crohn’s disease patients, which is another autoimmune gastrointestinal disease. The results were pretty phenomenal, and I think it’s kind of a landmark study because it really, for the first time, showed that AIP was able to induce clinical remission by week six in 11 out of 15 participants, so 73 percent of study participants, and all 11 maintained clinical remission during the maintenance phase of the study. This is quite remarkable. A 73 percent remission rate rivals even the most aggressive drug therapies, steroids and immunosuppressive drugs like Imuran and Remicade, which have side effects leading all the way up to death, and they were able to accomplish this with just a dietary intervention. Even though most of the evidence is anecdotal in AIP, we now have some peer-reviewed evidence supporting its use in autoimmune gastrointestinal disease. Certainly in my work with patients in the clinic, I’ve seen it be incredibly helpful for people with a number of different autoimmune diseases.
Other digestive disorders
Another group that may need to limit their whole grains and legume consumption are people with gut problems independently of autoimmune gut issues. This is a huge number of people, frankly. IBS is now the second leading cause of people missing work. Virtually every patient that comes to my clinic has gut issues. Many people that I just talk to because of my profession, a lot of friends and family members, come to me for advice, and in many cases it’s related to gut issues. I think it’s pretty safe to say that a large percentage of the population suffers from dysfunctional gut to some degree or another. Grains and legumes are often hard on the gut, and many people with gut issues feel better when they avoid or limit these foods.
One reason for that is that most legumes and some grains contain FODMAPs, and these are classes of carbohydrates that are poorly absorbed by some people and can provide food for bacteria that may be present in the small intestine where they shouldn’t be. So for people with SIBO or people with fungal overgrowth or other intestinal conditions, the FODMAPs can be problematic. In these cases, I’ve found that soaking and the other proper steps of preparation that I mentioned before for grains and legumes can help to some degree. I have patients, for example, who cannot tolerate unsoaked grains or legumes but can tolerate some amount of soaked and properly prepared grains and legumes. Experimentation can pay off there, but in general, I’ve typically found that people with these kinds of gut issues do feel better when they avoid these foods.
Customize your diet to meet your individual tolerance
Let’s just kind of wrap it up. When I wrote my first book, I suggested that the best approach is to start with a 30-day Paleo reset. I hope it’s clear why now. Even though whole grains and legumes … you may be able to include them in small amounts as part of an overall healthy diet, it’s best to try a period of time (usually 30 days, but sometimes more especially if you have an autoimmune disease), where you’re not eating them at all because that’s the only way you’ll get a chance to see how they are truly affecting you. And then, after you’re finished with that reset, you can start slowly adding back in the what I call “gray area” foods like grains and legumes, which we’ve talked about today, and also including dairy, particularly full-fat and fermented dairy, which I’ve written and talked about a lot in the past, and then see if you tolerate them.
If you tolerate them without difficulty, I don’t see a problem with including these gray-area foods in your diet with two caveats, which are that they’re not replacing more nutrient-dense foods, and you eat them in relatively small or moderate amounts. I’ve never seen any convincing research that whole grains and legumes when they’re properly prepared are significant contributors to the chronic disease epidemic.
Let’s face it, we didn’t get to where we are with two-thirds of Americans being overweight and one-third of Americans being obese by eating quinoa and lentils. We got here by eating pizza, drinking big gulps, having grain-based desserts, fried foods and all kinds of other processed and refined crap. That’s what has caused the chronic disease epidemic, not whole grains and legumes. The same is true for dairy, which I have talked about at length. If you look at the research on full-fat dairy overall, it’s very encouraging, and it really comes down to individual tolerance in that case. There are people who are intolerant of lactose, quite a few people actually, two-thirds of the population of the world, and there are people who are intolerant of the proteins in dairy. Those people obviously will not do well with dairy, but for people who don’t have either of those issues, and even for people with lactose intolerance, they can consume full fat from any dairy—foods like kefir and yogurt (especially if they’re made at home, where all are fermented to the point where lactose is removed), ghee, butter, and full-fat cream, which don’t have very much lactose or protein, but it’s really an individual thing. The research shows that they’re beneficial when they’re well tolerated.
I think that sums it up here. The moral of the story here is that if you’re able to eat small amounts of properly prepared whole grains and legumes without any difficulty or worsening of your symptoms, and you’re still eating a very nutrient-dense diet that contains organ meats, shellfish, herbs and spices, meat and fish, nuts and seeds, fresh fruits and vegetables, then that’s fantastic. Lucky you, you have a broader and more diverse diet and fewer limitations. If you have autoimmune disease or gut issues, you may need to be more careful with these foods and it would be even more important for you to do a reset diet where you eliminate these foods for a period of time before adding them back in and see how you tolerate them.
New book coming soon
Speaking of books, I wanted to mention that my next book, called Unconventional Medicine, is coming out on November 7th. I’m really, really excited about this book. It proposes a three-part solution to the growing epidemic of chronic disease that’s destroying our quality of life, bankrupting our governments, and threatening the health of future generations. Our current conventional approach to what I call “sickcare” rather than “healthcare,” because that’s really what it is when you think about it. It focuses on suppressing symptoms and managing disease rather than preventing and reversing disease by addressing the root cause.
We desperately need a new solution of true healthcare that can reverse these problems, restore people’s health, empower patients to take charge of their own health, and inspire healthcare practitioners to do the kind of work that they envision doing when they decided to enter medicine or healthcare in the first place. Unconventional Medicine lays out a vision for how we can do that. You can learn more about it and sign up to be notified when it’s released and for some really cool prelaunch stuff that we’re going to be doing with the book—free stuff, bells and whistles, that’s UnconventionalMedicineBook.com.
It’s kind of a tight timeline here. We’ve got a lot of other balls in the air and things going on, but I’m super, super excited about this book. I think you’re going to love it, and I hope you can join us in pushing this movement forward to reinvent medicine and healthcare. I think it’s something … it’s really my purpose here to end chronic disease and to create a new way of doing this.
Okay, everybody, thanks for listening. Keep sending in your questions to chriskresser.com/podcastquestion, and I’ll talk to you in a couple of weeks.