Oats are generally thought to be pretty healthy and nutritious and are marketed to the mainstream as a healthy food. However, like other grains and pseudograins, oats contain antinutrients – like phytic acid, lectins and avenin – which we try to avoid on the paleo diet. Let’s take a look at the pros and cons of the humble oat.
What are oats and where do they come from?
The oat plant is a species of cereal grain, grown for the edible seeds or ‘groats’. Once the husk is removed from the groat, it may be left whole, or processed into rolled oats (steamed and rolled flat), oatmeal (chopped into small pieces), or ground into oat flour.
Oats are a common livestock feed, but humans also like to eat them in muesli, granola, porridge, and baked goods. You can even brew beer from them!
Are oats paleo?
Oats are marketed as a health food as they are high in soluble fibre and complex carbohydrates. For a cereal, oats also have a reasonably high amount of protein (here’s a full nutritional breakdown).
However, we avoid oats on the paleo diet because (like other grains and legumes) they contain antinutrients which contribute to leaky gut, cause inflammation, weaken the immune system, and trigger autoimmune disease. Oats are also often contaminated with gluten from contact with other crops.
A run down on antinutrients
Avenin is a protein found in oats. For some coeliacs and gluten-sensitive people, avenin can trigger a reaction similar to gluten by irritating the intestinal lining.
Phytic acid (phytate)
Phytic acid is found in grains, nuts, seeds and beans. In oats, most of the phytic acid is found in the outer husk, or bran. Phytic acid binds minerals (like calcium, zinc, iron, and magnesium) and prevents us from absorbing them. A high phytate diet can result in mineral deficiencies, which cause diseases such as osteoporosis and rickets.
Lectins are proteins that are produced by plants as a defense mechanism – basically to stop their seeds being eaten by pests and insects, and to protect against microorganisms like mold and fungus. When ingested, lectins irritate the digestive tract causing discomfort (the idea being that the predator learns not to eat the seed again). Only certain types of lectins are toxic (like gluten). However those found in grains, legumes and pseudograins can cause digestive upset, damage to the intestinal wall, and an immune response. Read more about why you should avoid grains and legumes.
While oats are technically gluten-free, they can be cross-contaminated by other gluten containing grains (e.g. wheat, barley or rye) during processing. They can also be contaminated in the field, for instance if they are grown next to a field of wheat.
Carbohydrates and insulin
Aside from the antinutrients, oats are quite high in carbohydrates, and although the high fibre content lowers the glycemic index of oats, they can still cause a high insulin spike in your blood. Regular consumption of insulin spiking foods can insulin resistance and diabetes. We are all for healthy amounts of carbohydrates in the diet but it’s something to keep in mind.
Are there any ‘maybe’ caveats?
Many people love a comforting bowl of oatmeal and find it hard to give it up when switching to a paleo lifestyle. If you really can’t foresee a life without oats, there are a few things you can do when preparing your oats to reduce the impact.
Firstly, make sure you buy gluten-free oats. Secondly, reduce the phytic acid content. As oats contain very little phytase (which breaks down phytate), soaking oats is not enough to reduce the phytic acid content significantly. However, there are a couple of techniques you can try:
- Sprout and soak: malt (sprout) the oats for five days at 11ºC/52ºF, then soak for 17 hours at 49ºC/120ºF. This removes 98 percent of phytates. Try this method.
- Soak with a complimentary grain: add a small amount of ground wheat, spelt, rye, or buckwheat. The phytase in these grains is shown to reduce the phytic acid in the oats. Try this recipe.
- Soak and ferment: soak the oats with a complimentary grain (as above) in an acidic medium like whey, kefir or yogurt. Try this recipe.
- If you shop on Amazon US, there is this pretty good instant hot paleo cereal alternative that gets good reviews.
Paleo Oatmeal and Porridge Alternatives
If you find that you can’t tolerate oats, or you can’t be bothered to soak, ferment and cook them, don’t worry – check out these delicious no-oat oatmeal and porridge alternatives.
References & further reading
The Weston A Price Foundation: Preparing Grains, Nuts, Seeds and Beans for Maximum Nutrition
Mark’s Daily Apple: Are Oats Healthy?
Amanda Rose, PhyticAcid.org: Oatmeal and Phytic Acid
Precision Nutrition: All about Lectins
Mark’s Daily Apple: The Lowdown on Lectins