The Problem with Grains and Legumes
Prominently situated at the base of the food pyramid, grains are promoted as the fiber-rich foundation of a healthy diet. Yet, to the surprise of many people, there is a big problem with grains and legumes. Actually, there are four problems with grains and legumes!
If you have an autoimmune disease, you may already be aware of the fact that gluten, the protein in wheat that gives bread its sticky, doughy texture, is an inflammatory substance. However, wheat is not unique. Many of the plants that we consume contain similar proteins. These will also increase inflammation in your body and contribute to a leaky gut.
Most people benefit from avoiding foods such as grains, pseudo-grains, legumes, and nightshades. I recommend those with an autoimmune disease omit these foods from their diets completely, at least until their gut has healed. An elimination diet is the best way to uncover any other foods that could be causing sensitivities. Removing likely culprits from your diet and then reintroducing them one by one is the best course of action to determine if these foods will be a problem in the future.
To better understand the potentially harmful effects that they can have on your body, it is first necessary to understand the function of grains, pseudograins, and legumes in terms of plant biology.
What Are Grains and Pseudograins?
The grains that we eat are the seeds of the Poaceae family of grasses. These are also called cereal grasses. This family includes, among others, wheat, barley, rye, corn, millet, oats, sorghum, spelt, teff, rice, and wild rice.
Commercially, grains are divided into whole and refined varieties. The whole varieties contain the bran, germ, and endosperm. Think of whole-wheat flour or brown rice. Refined varieties are milled to remove the bran and the germ which also removes the iron and most B vitamins1. These include white flour and white rice, for example. Both types can be problematic.
Pseudograins are the seeds of broadleaf plants (non-grasses) that are used in the same way as rice or wheat. They are not part of the Poaceae family. They are often promoted as gluten-free alternatives. Examples include quinoa, buckwheat, amaranth, and chia seeds.
What Are Legumes?
Legumes are plants in the Fabaceae family, which bear fruit that grow in pods. Legumes can be further broken down into seeds and fruits. Snow peas and string beans are actually the fruit of a certain kind of legume plant. Kidney beans and lima beans, for example, are actually seeds of legume plants. Other members of the diverse legume family include alfalfa, lentils, soybeans, peanuts, and many others.
Why Should You Avoid Grains and Legumes?
The edible portion of these plants is the seed, which contains the embryo. A plant’s mission is to pass on its genes. Because a plant can’t move around, it relies upon animals to spread its seeds. A seed, therefore, is designed to withstand digestion, moving through the body in order to be “planted” on different soil.
There are several properties of a seed that allow it to survive the gastrointestinal tracts of animals. These properties all have the potential to cause harm and an inflammatory response.
Here are the four main problems with grains and legumes.
Grains and Legumes Contain Inflammatory Chemicals
What are Lectins?
You may have heard of this word and wondered, “What are lectins?” Lectins are plant proteins that bind to carbohydrates. Just like every other living creature, plants have evolved to survive and lectins help them do that. Because they don’t have teeth or claws, and they can’t run away, plants developed chemicals to repel pests. Lectins are one type of those chemicals2.
There are many different types of lectins, and not all of them are harmful to people. Yet, there is a strong relationship between lectins and inflammation. Gluten is the most well-known lectin. Agglutinins and prolamins are the two types of lesser-known lectins that can cause problems in humans. Let’s take a look at them.
Agglutinins function as a natural insecticide and can be an aggravating factor in autoimmune disease. The effects of lectins within our bodies can be subtle and hard to recognize, but some agglutinins are incredibly dangerous. For example, ricin, a lectin found in castor beans, a legume, is fatally toxic to humans even in very small amounts.
Other legumes, including kidney beans, are very high in this particular lectin as well. For example, raw kidney beans contain 20,000 to 70,000 lectin units. While the lectin content in beans and most other legumes can be reduced by cooking, the lectins in legumes and other plants that contain them generally cannot be completely eliminated by cooking.
Genetically modified organisms (GMO) grains3 are especially harmful when it comes to agglutinins. They produce more of their natural insecticides. This provides a heartier crop, yet one that is more inflammatory. If you do choose to include wheat, rice, or rye in your diet, for example, I recommend going for non-GMO and heirloom varieties which have fewer lectins.
Those with autoimmune diseases should also avoid vegetables in the nightshade family (Solanaceae), which includes tomatoes, peppers, and potatoes. These plants are very high in lectins that damage the gut lining and easily enter the bloodstream. GMOs are found among the legumes and nightshades, particularly tomatoes. If you do choose to eat these, avoid GMOs by selecting legumes and nightshades grown organically from heirloom seeds.
Prolamins are another lectin are necessary proteins for seed growth. They are not easily digested. The gluten found in wheat, for example, is a prolamin, and the seeds of other grains contain a prolamin similar in structure to gluten. For example, orzenin in rice or avenin in oats are prolamins. Prolamins contribute to the cross-reactivity experienced by so many with a gluten sensitivity. Yet, rice and oats are often used as gluten-free alternatives. Basically, these products simply substitute one lectin for another.
Phytates and Phytic Acid
Phytates and phytic acid occur naturally within the seeds of grains as a phosphorus store. Phytic acid inhibits digestion4. It binds to certain minerals such as zinc, iron, and calcium preventing their absorption. These minerals are vital for our immune system to function properly. Usually a small amount of phytic acid in your diet would not present a major problem, as long as you were getting adequate nutrients from the rest of your food. However, when grains are the basis of your diet, this may not be the case.
Again, GMOs comes into play. GMO grains contain a greater concentration of phytic acid. Choose heirloom varieties rather than GMOs if you opt to include grains in your diet. You can break down some of the phytic acid by slow cooking them, sprouting them, or soaking them overnight in water mixed with a little bit of lemon juice or apple cider vinegar.
These methods activate phytase, an enzyme present in the plant that breaks down phytates and phytic acid. However, if phytic acid-containing foods are a major part of your diet they can still prevent digestion and contribute to a leaky gut.
Grains and Legumes Strain the Digestive System
When you eat, your body produces enzymes to break down proteins into individual amino acids. However, you can’t perform this essential task when your enzymes are inhibited by the chemicals within a seed. This causes a chain reaction. You produce more enzymes using your body’s nutrients while not getting any in return. Worse, an overabundance of digestive enzymes will wear down the gut lining and contribute to a leaky gut.
Grains and Legumes Can Lead to Bacterial Overgrowth
An overabundance of partially digested food in the intestinal tract provides food for bacteria. A healthy balance of good bacteria is essential for your body’s overall well being. Because some bacteria will feed on partially digested grains and others won’t, it’s easy for an imbalance to occur. Bacterial overgrowth can lead to a wide array of problems and can even help to break down the gut lining.
Undigested Grains, Pseudograins, and Legumes Contribute to Leaky Gut
The gut is, by design, slightly permeable. The ability for some substances to pass through the gut lining is an essential function of our bodies. This process allows us to absorb nutrients from our food and fight infection. It also helps us assemble the proteins and enzymes that are necessary for life. However, the gut can become too permeable, and this can lead to autoimmunity.
Because you don’t completely digest them, grains, pseudograins, and legumes pass through your gut barrier intact. This helps to increase the permeability of the gut barrier in two ways. First, by damaging the cells that line the gut and second, by causing an inflammatory response once outside the gut.
Then the body responds to food particles with inflammation, which then damages the gut lining. And as I mentioned before, there is also a strong relationship in particular between lectins and inflammation. One the gut lining is damaged, it becomes even more permeable, allowing more undigested food, toxins, and bacteria to leak out.
It’s a vicious cycle. Your body can confuse these foreign “invaders” with your own tissues, a process known as molecular mimicry. Soon, the immune response gets out of control and begins to affect more tissues and systems within the body. Autoimmunity is the result.
When It Comes to Nutrition, Quality is Key
Grains, pseudograins, and legumes are not nutrient-dense foods. They can actually prevent you from absorbing the amino acids you need for a healthy immune system. Even varieties promoted as wheat-free alternatives are just as devoid of nutrients. Replace these inflammatory foods with healthier choices such as sweet potato, squash, and dark leafy greens.
Modern-day grains are bred so that they no longer resemble the varieties that our ancestors consumed. If you do choose to include wheat, rye, etc., pseudograins, and legumes in your diet, opt for non-GMO, heirloom varieties whenever possible to ensure a lower quantity of lectins and inflammation. Make sure to soak, sprout, and slow cook them. Try not to make grains or legumes the focus of your diet.
Those with autoimmune diseases would be wise to omit grains, pseudograins, legumes, and nightshades completely. Avoid nuts and seeds as well, which can be inflammatory. First, heal your gut. When you are symptom-free, you may be able to consume these foods every once in a while.
- Effect of Primary Processing of Cerals and Legumes On It's Nutritional Quality: A Comprehensive Review. Morteza Oghbaei, Jamuna Prakash. Taylor & Francis Online. 2015.
- Plant Lectins: The Ties That Bind in Root Symbiosis and Plant Defense. Peter L De Hoff, Laurence M Brill, Ann M. Hirsch. NCBI. 2009.
- Genetically Modified Plants and Human Health. Suzie Key, Julian K-C Ma, Pascal MW Drake. NCBI. 2008.
- Reduction of Phytic Acid and Enhancement of Bioavailable Micronutrients in Food Grains. Raj Kishor Gupta, Shivraj Singh Gangoliya, Nand Juman Singh. NCBI. 2015.
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