Grains & The Paleo Diet: The Do's/Don't And Everything In Between

Transitioning to a Paleo way of eating can be challenging at first due to the elimination of grains. Grain-based products are a staple in the Western diet and the thought of avoiding pasta, bread and rice seems impractical and unsustainable long term. Yet, despite the inclusion of a plethora of grains in both the US government’s food pyramid and the SAD (Standard American Diet), grains are simply not that great for you.

There are several problems with grains with the most relevant being:

  • Carbohydrate content
  • Anti-nutrients
  • Lack of nutrient density

Carbohydrate Content

The Paleo diet is not against carbohydrates but it definitely supports a lower carbohydrate load than that recommended in a standard, grain-based diet.

All carbohydrates are converted in our bodies into sugars (glucose) which is used for energy. Glucose needs to be moved from the bloodstream quickly and the pancreas produces insulin which allows the glucose to be distributed to your cells to burn as energy for various functions.

The glucose that is not used immediately is stored as glycogen, to be used by your muscles and liver and the rest as triglycerides, or fat, in the fat cells. Grains are very simple carbohydrates and break down into glucose quickly. This causes a spike in your blood sugar levels, which in turn causes a spike in your insulin levels. High insulin levels prevent the body from burning fat as it is focused on converting the excess glucose in the bloodstream into energy and storing the rest as fat.

Consuming too many carbohydrates and having constantly high insulin and blood sugar levels, can lead to a host of issues including insulin resistance, weight gain and obesity and diabetes

In addition to the high carbohydrate content, grains also contain a boatload of anti-nutrients that can negatively affect your digestion.


There are 3 main anti nutrients to consider:

  1. Lectins

Lectins are sticky proteins and anti-nutrients. They are found in various plant species including grains, legumes, as well as nuts and seeds in smaller doses. They evolved as a defense mechanism for the plant to discourage consumption by predators.

Lectins can be challenging to avoid altogether but a higher consumption of lectins can lead to intestinal damage, compromised intestinal bacteria, and leptin resistance – a pre-diabetic condition. Some people may experience diarrhea, nausea, bloating, reflux or vomiting when ingesting lectins.

Whether you experience symptoms or not, lectins can damage your gut lining, impair nutrient absorption, compromise your gut flora and interfere with your immune system

While lectins are not completely avoidable, grains contain the highest concentrations. This is one of the reasons the Paleo diet recommends avoiding grains and consuming more nutrient-dense foods with lower lectin levels.

  1. Phytates

Phytates are the salt form of phytic acid, a main form of energy storage in plants, and for humans are considered antinutrients. Grains and legumes have the highest phytic acid content, nuts and seeds have some and fruit and vegetables have none (except for some tubers and strawberries that contain small amounts). Phytic acid is problematic because it binds to minerals including calcium, iron, magnesium and zinc, preventing their proper absorption. Mineral deficiency is linked to conditions such as osteoporosis, skin issues, muscle cramping, PMS, fatigue, anemia, reproductive challenges and poor immunity. Humans do not have the enzyme necessary to break down this antinutrient (unlike ruminants, who do).

  1. Gluten

Many grains also contain the infamous protein gluten. The Paleo diet has emphasized how this potentially problematic protein can create issues for people beyond just those with celiac disease.

Eating gluten causes the secretion of a protein called zonulin, which regulates the tight junctions of the intestinal lining. When these tight junctions are opened unnecessarily, bacteria, toxins, and food particles can slip through the gut barrier. These intruding particles trigger the immune system, which can lead to a systemic inflammatory response.

Many individuals with autoimmune problems feel significantly better when they eliminate gluten from their diet, primarily because it helps calm down the inflammatory immune process in the gut.

Some of the most common reactions and symptoms associated with the effects of gluten are gastrointestinal issues, skin problems, autoimmune disease and mental health issues.

Unfortunately, even gluten-free foods, while better than gluten-full ones, present many of the anti-nutrients and carbohydrate issues discussed above.

Poor nutrient density. 

Nutrient-dense foods are rich in nutrients relative to their calorie content. The Paleo diet emphasizes nutrient density and encourages the consumption of well-raised proteins, organ meats, seafood, eggs, whole vegetables and seasonal fruits

Compared to meat, seafood, vegetables and fruits, grains are a poor source of bioavailable nutrients.

Safer Grains

White Rice

Rice is one of the more ‘acceptable’ grains in the Paleo community and is considered by many to be a ‘safe starch. White rice is gluten-free and contains little to no anti-nutrients. It is also made up of almost pure starch and contains no nutrients.

Interestingly, brown rice has high amounts of phytates and lectins and most of the fiber found in the husk is insoluble, meaning it does not feed the gut bacteria. Furthermore, it has been shown to contain significant amounts of arsenic.

Cooked white rice is low in phytates and lectins. When cooked and cooled, white rice develops resistant starch which can feed the microbiome. It is one of the easiest grains to digest, and is tolerated by many individuals.

People with blood sugar issues, gut infections, or autoimmunity may not tolerate a large amount of white rice in their diet.


Millet, like rice, is another apparent gluten-free option but has been found to contain high amounts of goitrogens. These are compounds in foods that inhibit thyroid hormone production. Those struggling with hypothyroidism may want to avoid millet. For most other people, choosing to consume, it will have few negative health impacts, but be aware that millet is still a grain and thus a nutrient poor, antinutrient rich food


Pseudograins are the starchy seeds or fruits of broadleaf plants as compared to cereal grains which are the starchy deeds of grasses.

The most common varieties are

  • Amaranth
  • Buckwheat
  • Chia
  • Quinoa

Pseudograins provide more nutrition than grains, containing B vitamins, magnesium, phosphorous, copper and manganese along with fiber and some non-heme iron. Pseudograins do however still contain a number of other proteins and substances that those following a Paleo diet would actively avoid including lectins, saponins, phytic acids, and protease inhibitors.


Amaranth is a gluten-free seed that haling from south and central America, it is rich in iron, magnesium, calcium, and protein. It is most commonly found as a flour and used in gluten-free baking. If choosing to consume, proper preparation using traditional steeping and soaking techniques is important. This helps to remove phytic acid and tannins whilst making the protein content more digestible.


Buckwheat is the seed considered a psuedocereal. It has a relatively high carbohydrate content for a seed. Although it is gluten-free, like most cereal grains it must undergo several processing steps to make it edible for humans 


Chia seeds, similar to flax seeds (a.k.a linseeds) have a high omega-3 fatty acid content and do not appear to contain many of the problematic compounds found in other grains and pseudograins. However, the potential benefits are somewhat overblown, as when consumed whole, the body is unable to digest and extract much of the nutrition. They do however provide a good source of soluble fibre that will support the gut microbiome. Inclusion of chia is an individual choice as it can cause gastrointestinal stress and inflammation to some but not others.


Quinoa is a relative of swiss chard and spinach. Although considered a complete protein, containing all nine essential amino acids, quinoa is also carbohydrate heavy. It contains a number of dietary minerals, including magnesium, manganese, iron, phosphorus, and zinc. Quinoa is gluten-free but still known to contain a protein (saponins) that can cause gastrointestinal distress, and so those struggling with gastrointestinal issues would do best avoiding quinoa completely.  


If you choose to include grains or pseudograins in your Paleo lifestyle, proper preparation is vital to eliminate a large proportion of the problematic phytates and lectins.

Sprouting, soaking and fermenting before consumption can drastically reduce toxins increasing their digestibility and nutrient availability. The Weston A. Price Foundation has some great resources on preparation methods.

In Conclusion

Although not part of a true Paleo template, including a small amount of safe starches in your diet may work for you and your lifestyle (and can help with transitions and social situations). As a healthy individual, including certain whole, gluten-free grains and pseudo grains as part of your diet and lifestyle is personal decision. Either way, these foods should never make up a large portion of your diet and one needs to be aware of the potential problems they can cause. Proper preparation is key to maximize nutrient absorption and minimize and toxic effects

Personally, I would advise concentrating on more nutrient dense, less problematic foods that are more closely resembled to the diet of our ancient ancestors. If you are suffering from digestive issues, autoimmune disease or nutrient deficiencies, the inclusion of any grains or pseudograins is not recommended.

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