Anatomy of the Grain-- By Robb Wolf
You have likely heard terms like Bran, Kernel and Germ as they relate to grains, but I want to take a moment to cover what exactly these structures are and what they contain. This general diagram from the Linus Pauling Institute illustrates the normal grain constituents. Here is what we find in the grain:
Bran: The tough outer coating that contains proteins, vitamins and minerals. That’s the standard ADA position. (Eatright.org… what a damn farce. Keep your eyes open for that topic and others at our new blog… Sorry, back to bashing grains.) So the bran appears to be a bountiful harvest of nutrition. We will take that fallacy apart in greater detail later. For now just know that bran is also home to most of the antinutrients and gut-irritating protein constituents.
Kernel: This is where most of the nutritional action is, at least with regard to caloric content. This is where we find most of the carbohydrate in grains. If you have seen white rice you have seen the kernel.
Germ: This is actually the plant embryo and it contains a fairly dense source of fatty acids, mostly n-6, some protein and assorted vitamins and minerals. This is your average grain, and it is representative of grains ranging from wheat to rice to popcorn. A detailed understanding of grain taxonomy and structure is not my intent here, but it is important that you understand the components grains, as we will be talking about processing methods that may remove certain problematic fractions but inevitably leave others.
The Real Problems: Most of the problems related to grain consumption can be lumped into one of two categories: those related to hyperinsulinemia and those related to irritant/toxicant properties inherent to the grains. It is interesting to note that these properties of irritation and inflammation via hyperinsulinemia may be multiplicative with regards to deleterious health effects, i.e. one makes the other worse. Did the food pyramid make all the Dieticians Chubby or did the Chubby Dieticians make the food pyramid? Possibly the longest introduction for a paragraph you have ever seen but it is at the crux of the first problem with grains. Grains are mostly starchy carbohydrate, and starchy carbohydrate, when consumed in any amount, causes the release of a significant dose of insulin.
The starch in grains can be subdivided into two basic forms, amylose and amylopectin. Amylose is a long chain of glucose molecules and amylopectin is a highly branched, interwoven structure also comprised of glucose molecules. Think of amylose as a rope and amylopectin as a dust bunny. Grains are made up of differing amounts of amylose and amylopectin, and this variation accounts for differences in the glycemic index of various grains. Starches are digested by the enzymes salivary amylase and pancreatic amylase. Amylase acts on the last glucose molecule in the polymer, whether it is amylose (rope) or amylopectin (dust bunny). I think it’s pretty clear that the rope has far fewer locations for the amylase to attack in the digestion process than the dust bunny does. The more locations for the enzyme to attack, the faster the digestion, the quicker the rise in blood glucose levels, and typically the larger the insulin release. Any type of processing (cooking, milling) breaks up both the varieties of starch molecules, thus facilitating digestion. Easier digestion means a greater insulin response. The making of pizza crust fractures the starch grains in such a way that the body produces more insulin in response to pizza crust than raw glucose!
No one knows why, but the processing inherent in most grain products can increase the insulin response far above what would otherwise be expected. So grains can have a fairly wide-ranging glycemic index and thus insulin response and various forms of processing can greatly increase both those numbers and consequently their impact on our health. One of the fallacies that is still spewed forth by the likes of the ADA is that slow-releasing carbs (beans, whole grains) causes a flat insulin response and consequently do not pose a problem. This is true only if one is consuming grains as condiments, as in a tablespoon here and there. Eat them a cup at a time, and not only does blood glucose level rise dramatically, but it stays elevated for a long time. Research is pretty conclusive that the insulin spike is more detrimental than the lower level chronically elevated insulin, but the end results are the same: Syndrome X, AKA the Metabolic Syndrome (You always need multiple names for things in science and medicine to ensure that as few people as possible have an idea of what is going on).
Grains, both processed and unprocessed, are a major player in metabolic derangement in that they are almost entirely carbohydrate and they are typically consumed in large quantities. Now that we understand the relationship of grain consumption and the inevitable and deleterious rise in insulin levels, let’s look more closely at what Syndrome X is. The word Syndrome is defined as “A collection or group of signs and symptoms that occur together and characterize a particular disease or abnormality.”
The signs and symptoms of Syndrome X include high triglycerides, low HDL cholesterol, high blood pressure, high risk of stroke and heart attack… and a bunch of other stuff. Professor Loren Cordain wrote a paper that sheds some light on some of that “other stuff” Called “Syndrome X: Just the Tip of the Hyperinsulinemia Iceberg”. That other stuff runs the gamut from cancer to myopia, but many diseases that have been associated with Syndrome X and hyperinsulinemia are slowly being put under the umbrella of Chronic Inflammation.
We know that we are onto something hot when Barry Sears has a new topic that allows him to re-hash his Zone offerings. The Anti-Inflammation Zone is his most recent contribution to the Zone book club. [Just a small digression here, but I think we are going to adopt Barry Sears’s approach to rehashing material and combine that with the consistent subject lines of my Spam and we will start re-releasing the P-Menu with catchy titles like “The Anti-Penile Dysfunction P-Menu” or the “Better than Cialis P-Menu”. No new content… just a new topic to hang the material from.] Anyway, inflammation has many factors, including antioxidant and essential fatty acid status, but one of the key contributors to the condition we call inflammation is insulin level. Here is a detailed look at what happens with elevated insulin levels (Scroll down to insulin dysregulation). The insulin and inflammation topic is absolutely huge and far beyond the scope of this article or publication for that matter. The main point is grains pack a potent impact with regards to insulin response and that can lead to a variety of problems. Irritant/Toxicant The next broad category I want to look at falls under the irritant/toxicant label. Let’s look first at antinutrients. Grains are essentially a reproductive structure and contain not only a dense energy source for the developing embryo, but also a number of control mechanisms that prevent both predation and abnormal germination. Sequestering away key nutrients like calcium, zinc and magnesium prevents abnormal germination.
One of the main antinutrients is a chemical called Phytic acid of which there are several varieties, all going by the general term “phytates”. Now the phytates are powerful chelators; that is they bind to metal ions very tightly. This is postulated to be the main reason why cultures that consume large portions of their diets as grains and/or legumes tend to be shorter than their westernized transplants. The Okinawan vs. Japanese story is clearly illustrative of this. Okinawans have historically been significantly taller than their Japanese counterparts. The diets of the two groups differed in that the Okinawans consumed more protein and most of their carbohydrates in the form of highly nutritious tubers and only a modicum of rice. Japanese Americans show a markedly different phenotypic expression than their rice and tofu-eating ancestors. Just look at Jeff Oji.
It is interesting to note that phytates are used in some alternative medicine circles as an anti-cancer agent. Apparently phytates exert some influence on the growth of tissues by removing metal ions such as calcium, magnesium and zinc that are important for growth. This seems like a nice closed system: feed people grains, let them get cancer from the elevated insulin levels then use grain extracts (phytates) to try to treat their condition. This antinutrient concept is found in all eggs including those of birds and reptiles. Avidin binds to biotin, which is an important growth factor for bacteria. Hide away the biotin and it’s hard for the egg to spoil. These antinutrients are so powerful that avidin has even been genetically engineered into some grains… to extend their storage. Avidin is destroyed with cooking but phytates are not. Bon appetite! Another sub category of irritants/toxicants includes items such as gluten.
It is interesting to note that phytates are used in some alternative medicine circles as an anti-cancer agent. Apparently phytates exert some influence on the growth of tissues by removing metal ions such as calcium, magnesium and zinc that are important for growth. This seems like a nice closed system: feed people grains, let them get cancer from the elevated insulin levels then use grain extracts (phytates) to try to treat their condition. This antinutrient concept is found in all eggs including those of birds and reptiles. Avidin binds to biotin, which is an important growth factor for bacteria. Hide away the biotin and it’s hard for the egg to spoil. These antinutrients are so powerful that avidin has even been genetically engineered into some grains… to extend their storage. Avidin is destroyed with cooking but phytates are not. Bon appetite! Another sub category of irritants/toxicants includes items such as gluten.
Gluten is a protein found in wheat and other grains. It is also categorized under a huge family of molecules called lectins. Many of these lectins actually damage or destroy the gastrointestinal tract. In the small intestine we have structures called microvilli that interact with the food in our intestines. Microvilli are covered with enzymes that help to digest and transport food particles into the blood stream or lymph. Certain proteins such as gluten found in wheat, rye and barley cause a severe autoimmune reaction in some individuals, which is called Celiac Sprue. Celiac is a full-blown autoimmune reaction in which the microvilli of the intestines are destroyed. This condition makes it nearly impossible to absorb fats, minerals and many vitamins. Not everyone shows a full blown celiac response; however, irritation is present with virtually all grain consumption.
This lower level irritation has been broadly labeled as “leaky gut syndrome” and is emerging as a primary player in all autoimmune disorders. The theory is that once the gut lining is damaged, large food particles are able to make their way into the blood stream. Once there, the immune system mounts an attack against the foreign, undigested food particles. These particles may have elements that are similar in structure to body proteins and thus antibodies are produced that have affinity for one’s own tissues. The seed of autoimmunity has then been sown (nice grain cliché, no?). This is something that has been kicked around for many, many years, but some other very interesting disease processes have been uncovered, like schizophrenia and congestive heart failure, which appear to owe their existence, at least in part, to leaky gut. Nay Sayers (read also: The Ignorant) frequently make the point that not everyone gets celiac. That is true, but across all species tested, grains cause gut irritation. Check PubMed. This knowledge has even allowed the design of experiments looking at gut permeability and autoimmunity.
It is worth mentioning that dairy is a potent cross reactor for celiacs. It is fairly easy to assay dairy and get high concentrations of grain lectins. It has also been noted that grass-fed dairy shows little or no cross reactivity in celiacs. I’m going to look at some of the other deleterious effects of grain consumption for animals later, but this is obviously a source of grains that most people would not have considered. Just to completely beat this into the ground, let’s look at quinoa. Quinoa is similar to a grain in its carbohydrate content and layout as a reproductive structure, but quinoa is botanically a fruit, and if you remember your botany, is a dicotyledon, whereas wheat, obviously a grain, is a monocotyledon. Relevance? They differ phylogenetically at the class level. To put that in perspective, mammals are a class, as are fish, as are reptiles. This is a huge difference and denotes ages since a common ancestor. Despite that fact, quinoa still has a protein fraction that can cause problems with celiacs. What I take from this is nature found a similar answer to reproductive strategies with quinoa and grains, and not surprisingly, quinoa presents similar potential problems. I want to mention just a few more things here. Grains also have a highly addictive nature beyond the carbohydrate content. They contain opiate-like substances that can be very problematic. Not surprisingly, these opioid constituents can be concentrated in dairy. Makes one look at pizza in a new and frightening way.
Grains are not just bad for humans; they give livestock some serious problems as well, ranging from creating heat and acid resistant forms of E. Coli to completely altering the fatty acid and nutrient content of meat. Grass-fed meat should contain significant amounts of n-3 fatty acids, alpha lipoic acid, CLA, Vitamin E and loads of carotenoids. Grain fed meat is the protein version of cardboard.
You Have It! So, there you have it! Likely more than you EVER wanted to know about grains. But considering that our mission with the Performance Menu is to provide the best possible information on how to feed, water and exercise your person to optimize performance, health and longevity, avoiding such thoroughness with the topic would be a dereliction of our responsibilities. We advocate a Paleo/Zone approach to nutrition and jazz that up with some Intermittent Fasting. We feel strongly that both anecdotal and scientific research supports these positions. Grains obviously play a major dietary role for many people, but I hope this exploration helps to clarify why they may not be a wise choice for optimized health.
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