DEAR DR. BLONZ: I came across the term “antinutrient” and wanted an explanation of what this means. It was mentioned that they are present in some foods. I have had trouble getting a clear answer. -- S.T., Phoenix
DEAR S.T.: Antinutrient refers to a substance that works in opposition to how a nutrient would typically function. This could involve an interruption in any step from how a nutrient gets absorbed to how the body would eventually utilize it. We often find antinutrients in plants. They can be a part of the plant defenses to deter animals from eating the plants lest they get sick. Antinutrient effects can range from blatant toxic effects to interference with digestive enzymes, to preventing essential vitamins or minerals from being absorbed or working. It’s quite a variety.
For example, a precursor to the deadly poison cyanide is present in some plants, including raw sweet potatoes and cassava. Solanine is a toxic compound produced in green or sprouting potatoes. Raw legumes contain enzyme inhibitors that prevent normal digestion. Grains and legumes contain phytic acid that can bind certain mineral nutrients and inhibit their absorption.
Animals eating such foods in excessive amounts can suffer ill effects, and many learn what to avoid. The risks are less for us if we prepare foods to avoid or deactivate any antinutrients.
Of course, we have more choices of what to eat than animals in the wild. Traditional methods of food preparation tend to take antinutrient foibles into account. For example, raw egg white contains the substance avidin, which binds with biotin, an essential nutrient. Having raw eggs as a regular part of your diet will eventually give rise to a biotin deficiency that can cause scaly dermatitis, referred to as egg-white injury. This malady is first noticed on the skin, perhaps because the skin is our largest and most noticed organ, but if seen on the skin, it is also causing problems throughout the body. This damage is easily stopped by stopping the consumption of raw egg whites.
Antinutrients are present throughout nature; think of them as a method lent by evolution to help plant species survive excessive poaching by insects and animals. Opting for a variety of foods and using appropriate methods of preparation are good strategies to limit the risks of antinutrients. (Read more on antinutrients at b.link/kyw95.)
DEAR DR. BLONZ: In a recent column on canned beans with salt, I was disappointed that you did not mention the option of purchasing frozen cooked beans that can be bought with no salt added. I have seen them at most grocery stores. -- M.L., via email
DEAR M.L.: Sorry for your disappointment. I had mentioned other canned beans as this was what the writer asked about and had in their pantry. I could have added using fresh beans, where soaking is a part of the prep, and I could have also mentioned the option of buying frozen beans, as you suggest. Thanks.
Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to firstname.lastname@example.org. Due to the volume of mail, personal replies cannot be provided.