Anti-nutrients exist naturally in plants and serve a number of functions. They received their name as they bind other nutrients (such as minerals) eaten in the same meal, reducing their absorption. Examples of anti-nutrients include phytates, lectins, and glucosinolates.
It is important to note that anti-nutrients may also have beneficial effects, and the foods that contain anti-nutrients may have many other benefits that outweigh the negative side of reduced mineral absorption such as vitamins, phytonutrients, and fiber.
What Are Anti-Nutrients? What Foods Contain Anti-Nutrients
Here are four common types of anti-nutrients and where they’re found along with pros and cons of each.
- Found in coffee, tea, and legumes
- May decrease iron absorption
- Potential benefits may include antioxidant effects, anti-inflammatory effects, and support for cardiometabolic health, brain health, and cancer prevention
- Oxalates (oxalic acid):
- Found in green leafy vegetables, beets, tea, cocoa, nuts, and seeds
- May decrease calcium absorption
- Potential benefits include Oxalobacter formigenes, a bacteria found in the digestive tract that uses oxalic acid for energy and reduces how much your body absorbs
- O. formigenes may be decreased when a person experiences IBS; after gastric bypass; or when taking antibiotics (increasing absorption of oxalates and increasing risk for kidney stones).
- Found in cruciferous (brassica) vegetables
- May decrease absorption of iodine
- Glucosinolates have many potential benefits, which may include antioxidant and anti-inflammatory effects, healthy detoxification of hormones, cancer prevention, cardiometabolic health, and more
- Found in beans, lentils, peas, soybeans, peanuts, tomatoes, potatoes, and eggplant
- May decrease absorption of calcium, iron, phosphorous, and zinc
- May benefit cardiometabolic health, immune health (except if an autoimmune condition that has formed antibodies to lectins), and digestive health, and help with cancer prevention
Traditional preparation techniques may reduce or deactivate anti-nutrients. The question, then, is whether this is a good thing or bad. Should we eat anti-nutrients?
To Eat Anti-Nutrients or Not?
It is almost (if not completely) impossible to avoid anti-nutrients when eating a plant-forward diet. Anti-nutrients tend to get a bad rap as they are phytonutrients with at least as many benefits as they have drawbacks.
Here’s how to optimize nutrient absorption even when consuming foods with anti-nutrients.
- One important factor affecting tolerance is often digestive health; learn more about supporting digestive health.
- Food is meant to be a sensory experience. So, consume a diverse vegetable-forward diet containing seasonal vegetables. Eating a variety of vegetables as opposed to large amounts of just a few vegetables helps to ensure that you are obtaining the vitamins, minerals, phytonutrients, and fiber your body needs.
- Spacing helps! If you know you are going to eat a meal that contains unusually high amounts of anti-nutrients, try spacing it away from other nutrient-dense foods so that there is less of an impact on nutrient absorption. (The exception to this is if you have calcium oxalate kidney stones and are on a low oxalate diet. If so, then consuming foods rich in calcium along with foods that contain oxalates may be beneficial).
- Anti-nutrients can only bind so much, not having unlimited binding capacity. So, although they may bind some minerals in a meal, whole foods containing anti-nutrients are often mineral-rich.
- Enjoy coffee and/or tea between meals.
- When it comes to grains, beans, and nuts, traditional preparation techniques including soaking, sprouting, fermentation, and high heat cooking with moisture can help to reduce anti-nutrients.
Vegetarians eating diets high in plant foods that contain anti-nutrients do not generally show deficiencies in iron and zinc based on current research. One theory is that the body may adapt to anti-nutrients in the diet by increasing mineral absorption in the digestive tract.
The amount of anti-nutrients in a plant also depends on growing conditions and soil quality.
Soaking and Sprouting
Soaking and sprouting not only reduces anti-nutrients but may increase digestibility along with nutrient availability (such as B vitamins, vitamin C, phytonutrients (antioxidants), and amino acids (increasing protein content)) in grains and legumes.
Cooking with dried beans is one of my favorite meal prep ninja moves because they are so versatile and can be made ahead and incorporated into a variety of meals throughout the week. Plus, dried beans are usually more economical and they allow you to delve into the wonderful world of unique heirloom beans that you cannot find in cans. With a little bit of planning, it is easy to prepare beans in a way that optimizes flavor, nutrients, and digestibility.
To soak dried beans, start the night before by measuring them out into a clean container. Then add plenty of filtered water to cover the beans by at least three times their dried volume. Cover the container and allow it to sit on the countertop or place it in the refrigerator until the next day when ready to cook. Drain the soaking water, rinse, and add fresh filtered water. Cook as directed based on the legume or grain you are using. Lectins are usually found on the surface of legumes and grains and are water soluble so, by pouring off the soaking water, you are effectively reducing lectins.
Soaking raw legumes, nuts, seeds, or grains for longer periods (12-24 hours) and then rinsing and changing the water every 12 hours while maintaining good air circulation (I highly recommend sprouting trays or sprouting lids) can cause them to sprout. Not all grains, nuts, or legumes will sprout, so research first to find directions specific to the food you wish to sprout.
Cooking at higher temperatures and in a liquid may help to reduce anti-nutrients (such as lectins, which have the most negative effects in their raw state). Consider using a pressure cooker or instant pot, or cook them covered on the stovetop. Crockpots may not get hot enough to optimally reduce anti-nutrients, especially if not soaking first.
Although I am not a huge fan of boiling vegetables, if you are trying to lower oxalates, boiling them for 12 minutes can reduce their oxalate content by 30-87%. The problem is, you also decrease other nutrients, as well. Steaming lowers oxalates by about 45% and is likely a better option to retain vitamins and minerals in the vegetable being cooked.
Fermentation is a fantastic way to reduce antinutrients, increase nutrients, support the microbiome, and enjoy vegetables and other foods in new and exciting ways. Learn more about the benefits of fermentation. (link to fermentation e-book).
Optimizing Health Based On Your Needs
Our new Farmacy at The Chef’s Garden Health and Wellness Collection helps you to choose fresh vegetables that are nutrient-dense and regeneratively grown that meet your unique needs wherever you are along your health and wellness journey. We understand the power of food as medicine and want to share our nutrient-rich vegetables with as many people as possible. Our goal is for the farmer to become part of the health and wellness team. We hope that you will join us. Share your photos with us on @farmerjonesfarm and @amysapola and join our Farmacy Family on Facebook.