All About Antinutrients
Compounds in some grains, legumes, nuts, and seeds can wreak havoc on your digestion. Learn how to make them work to your advantage.
If grains give you gas and beans make you bloat, you’re not alone. Many people experience uncomfortable digestive symptoms, including gas, swelling, cramping, and pain, after eating legumes, grains, beans, and many seeds and nuts. The common denominator? These foods are all relatively high in natural compounds called antinutrients.
As the name suggests, antinutrients can interfere with the body’s ability to absorb vitamins and minerals. They may also cause damage to the intestinal lining and trigger an inflammatory response elsewhere in the body.
With this in mind, you may be inclined to give up the offending foods altogether. After all, abstaining from antinutrient-laden fare is a cornerstone of many elimination diets, which are designed to help people identify nutritional triggers for sensitivities, allergies, or digestive ailments. Some people suffering from seemingly unrelated symptoms — migraines, joint pain, or asthma, for instance — experience a reduction in symptoms when they steer clear of these foods.
Avoiding antinutrients is also part of the popular paleo philosophy, which eschews relatively modern (think postagricultural revolution) foods such as dairy, sugar, refined oils — and cultivated legumes and grains.
But there’s more to antinutrients than their malevolent name and digestive crimes suggest. Think of antinutrients as the unexpected hero of the ancestral-diets world: oft-misunderstood villains that may play a greater role in our well-being than they’re given credit for.
Learning more about antinutrients, including how to work with them, can offer much-needed relief and allow you to enjoy a wider variety of foods.
THE GOOD WITH THE BAD
The first step toward establishing a better relationship with grains, legumes, seeds, and nuts is to see them in their evolutionary context.
“Every living thing has a defense mechanism,” says Diane Sanfilippo, certified holistic-nutrition consultant and author of Practical Paleo.
For animals, it’s the ability to fight or flee. Plants, however, can’t run away or put up their dukes. Some plants have thorns or hard outer shells that help protect them from being eaten; others guard themselves via antinutrient compounds that are difficult for animals — including humans — to digest.
Antinutrients behave in different ways in the human body. Some bind up important minerals like calcium, iron, and zinc, interfering with the body’s ability to use them. Others have been found to cause gut inflammation and irritate the digestive lining, says Maggie Ward, MS, RDN, LDN, nutrition director of the UltraWellness Center in Lenox, Mass.
But antinutrients also offer some important health benefits.
“Most things in the natural world have a risk–benefit ratio,” explains Ward. “Many of these compounds are phytochemicals that have a supportive effect on our immune systems, or serve as antioxidants to protect our cells from oxidative stress.”
The antinutrient phytate, for instance, has been shown to neutralize free-radical formation, according to research published in The Journal of Nutrition. As for broader health benefits, other studies suggest consumption of phytates can prevent osteoporosis and promote better blood-sugar control.
In the Nurses’ Health Study 3, a long-term epidemiological study of women’s health, women who ate the most phytate-rich diet had the lowest risk of developing kidney stones compared with those who ate the least.
Lectins are another example of antinutrients that can be beneficial. While some can spur inflammation, others have an anti-inflammatory impact on the body, according to research published in the journal Molecules. The defense role that lectins play in nature may also make them especially well suited to help fight off cancer cells. Researchers are investigating various types of carbohydrate-binding lectins for their antitumor properties.
Another reason to choose antinutrient-containing foods — unless you’re sensitive or allergic to them, of course — is that they’re important sources of healthy plant-based fats, proteins, and carbohydrates. And they provide bacterial diversity for your microbiome, which is increasingly understood as critical to overall health.
In one study published in Applied and Environmental Microbiology, extreme low-carb dieters (24 grams per day, roughly the amount in one small banana) experienced disproportionate decreases in fecal butyrate, the short-chain fatty acid produced by bacteria in the colon that can protect against colon cancer and inflammation.
Other research finds that people using the low-FODMAP diet, a plan that limits foods like beans and wheat to manage irritable bowel syndrome, experience decreases in beneficial gut bacteria.
SEEK A MIDDLE WAY
If you have a condition related to inflammation or gut health, antinutrients may indeed be playing a problematic role, say experts. In many cases, taking a hardline approach and permanently exiling the offending foods is the only way to help the condition. (People with celiac disease should avoid all gluten, for example.) In other cases, a moderated approach to antinutrients may be more appropriate.
“The terrain is everything,” says Sanfilippo, who recommends that the paleo diet be considered more of a short-term elimination diet than a lifelong exercise in bread-shunning. It is more beneficial, she says, to figure out what your body can tolerate and reap the benefits of a more varied diet.
For instance, both Ward and Sanfilippo advise clients with compromised digestion or signs of increased inflammation to eliminate beans. They may eventually suggest reintroducing beans that have been soaked and cooked to find out what the clients can tolerate and, ideally, expand their eating options. (For more traditional methods for reducing problematic antinutrient activity in food, see “Make the Most of Antinutrients,” below.)
If you don’t have a diagnosis but feel “off” whenever you eat certain foods, carefully experiment with eliminating and then reintroducing the offending fare. You may find, for instance, that while super-refined grocery-store bread makes you uncomfortable, traditionally baked sourdough doesn’t bother you at all.
For most people, the impact of antinutrients on their bodies is best discovered through some dietary detective work, rather than by subscribing to one nutritional approach. Relying on your own judgment — perhaps with a little guidance from a registered dietitian nutritionist, or practitioner trained in holistic health — can help you discover the foods that best suit you right now.
Illustration by Stuart Bradford
5 Tough-to-Digest Antinutrients
As part of a plant’s self-defense and security system, antinutrients make the plant hard for animals (including you) to eat and digest. These antinutrients are known to cause trouble for some people.
What it is: Proteins found in wheat, rye, barley, and triticale.
What to know: Gluten can cause inflammation and digestive problems in many people. Those with celiac disease experience an immune response when exposed to gluten.
What it is: The storage form of phytic acid, phytates are found primarily in the outermost layer of the endosperm as well as the germ layers of grain foods like wheat and rice; they're also found in nuts like almonds and walnuts and seeds like flax.
What to know: Phytates have a tendency to stick to phosphorous and other minerals such as iron and zinc, interfering with how well the body can absorb these nutrients.
What it is: A class of carbohydrate-binding proteins found in beans, grains, seeds, and nuts.
What to know: In some people, lectins may trigger an immune response as well as diminish the production of mucus, which helps keep the lining of the gut healthy.
What it is: A group of phytochemicals found mainly in legumes like soybeans and chickpeas.
What to know: Saponins may be poorly absorbed and trigger gut inflammation in some people.
What it is: A compound found in soybeans and peanuts, as well as in vegetables like spinach and rhubarb.
What to know: Similar to phytates, oxalates bind to minerals like calcium, making them harder for the body to use.
Make the Most of Antinutrients
In traditional cultures, soaking, sprouting, and fermenting foods are time-honored ways to make antinutrients easier to digest and to increase the availability of health-promoting nutrients. Try these techniques to see if they lessen the discomfort or inflammation caused by the legumes, grains, nuts, and seeds you eat.
Soaking foods high in antinutrients can significantly reduce lectin and phytate content, says John Bagnulo, MPH, PhD, a nutritionist in Yellow Springs, Ohio. For example, one study of home-based processing techniques used in Malawi, Africa, found that soaking maize flour reduced its phytate content by up to 57 percent — a difference that Bagnulo finds can help people better tolerate foods like grains and beans.
Maggie Ward, MS, RDN, LDN, director of nutrition at the UltraWellness Center in Lenox, Mass., says that soaking or rinsing quinoa in warm water can remove saponins, taking out bitterness and also reducing the chances they will cause inflammation. (For specific soak times for individual foods, see “Smart Soaking and Sprouting,” opposite page.)
Eat raw seeds and nuts and you’ll miss out on some of the vitamins and minerals that remain bound up and protected as they pass through your body. Eat them sprouted, however, and you’ll have access to more bioavailable nutrition.
“When you sprout foods like grains, seeds, and legumes, it’s almost like you’re tricking them into thinking the seeds have been planted,” says Diane Sanfilippo, a certified holistic-nutrition consultant. Sprouting causes these foods to let down their guard (lowering phytate levels) and release some of those nutrients they hold on to so tightly.
Researchers in India found that the iron in sprouted and dried millet was 300 percent more accessible than that in the unsprouted grain; levels of the minerals manganese and calcium also increased.
Sprouting also seems to increase disease-fighting antioxidants. When researchers compared the nutritional content of white rice, brown rice, and sprouted brown rice, the sprouted rice came out on top, according to a study published in the journal Food Chemistry. Other research finds that sprouted wheat and rice are higher in fiber than their unsprouted counterparts.
A note of caution: Sprouts grow in warm, humid conditions, which can cause bacteria to proliferate. “Those with compromised immune systems — the very young and old, and pregnant women — should use extra caution,” says Ward. “If you eat sprouted foods like bean sprouts, it is best to cook them and not eat them raw; cooking should kill dangerous microbes.”
If you’ve eaten sourdough bread, you already have experience with fermented grains. “Traditionally, cultures used to ferment most of their grain flours into sourdough to help preserve and reduce the presence of pathogenic bacteria,” says Ward. Using a live sourdough culture to make bread helps break down as much as 70 percent of its phytate content.
After you soak dried beans or grains, rinse them thoroughly and add more soaking water along with a dollop of yogurt or kefir. These active cultures will help to break down the difficult-to-digest compounds. Alternatively, you can simply allow the grains or beans to sit overnight and “wild ferment” from naturally occurring microbes in the air, suggests Bagnulo.
Any film you see on top of the soaking water, says Bagnulo, is low-level fermentation that is “cleaning up your legumes.” In a study from Sweden, allowing beans to ferment for 48 hours resulted in an 88 percent reduction in phytate. Be sure to rinse your beans and grains before you cook them.
Smart Soaking and Sprouting
A little soaking or sprouting may be all that stands between you and some of your favorite beans, grains, nuts, and seeds. This simple guide, courtesy of DaNelle Wolford of the blog Weed ’Em & Reap, can help you get started.
- Soak your beans, grains, nuts, or seeds in water (1:2 food-to-water ratio) at room temperature for the amount of time specified in the chart below. You can add 1 to 2 tablespoons of apple-cider vinegar to further break down antinutrients.
- Drain the liquid, and cook grains or beans normally if soaking is your final step. Eat your nuts or seeds, turn them into nut or seed milk, or grind them into a butter.
- To sprout, rinse your grains, beans, nuts, or seeds after soaking; drain the liquid slowly, leaving some moisture. Rinse and drain at least twice a day, at minimum, until they begin to sprout (seeds, legumes, oats) or split (nuts and rice); refrigerate and eat within two to three days.