Even if you haven’t heard the term “anti-nutrient” before, you’ve probably heard terms that would fall under the category. Although I have problems with the term itself, commonly referenced anti-nutrients include lectins, tannins, oxalates, phytates, and solanine.
The term anti-nutrient is derived from the idea that certain compounds in foods bind to essential nutrients in digestion, reducing their absorption. This process does actually happen, but the idea that you should avoid foods with these substances is faulty on a number of levels.
What types of foods contain these supposed anti-nutrients? Beans, peas, and lentils are the most well-known sources of lectins, but the majority of fruits and vegetables have them too – and don’t forget nuts, garlic, coffee, chocolate, and coconut. Tannins are found in tea and red wine, oxalates occur in spinach, and phytates come from whole grains, nuts, and seeds. Solanine is found in nightshade vegetables like tomatoes, peppers, and eggplant.
Take a good look at the foods listed in the above paragraph. Are these really foods that you want to exclude from your diet? Absolutely not. Most of these are foods that we should actually be eating more of, for a variety of reasons.
The effects of these substances vary. Lectins can cause nausea and diarrhea, but only when eaten in certain forms like in uncooked kidney beans. As long as you cook your beans, however, there’s no reason to worry. Tannins can reduce absorption of iron, oxalates bind to calcium, phytates affect zinc digestion, and solanine can be poisonous – but only if isolated and concentrated in large amounts. You’ll never have to worry about solanine poisoning from tomatoes, peppers, or eggplants. It is wise, however, to cut off the green sections of old potatoes before eating, as this can indicate elevated amounts of solanine. You’d want to do this anyways since these parts of the potato will be bitter-tasting.
There are ways to reduce the presence of some of these compounds (like sprouting beans before you eat them), but for the most part there’s no reason to worry about it. While specific substances may not function exactly how we’d like them to in digestion, it’s important to look at the full picture of each food without trying to just nitpick the individual components. Foods like beans, spinach, nuts, and peppers are extremely nutritious, and healthy populations tend to eat lots of these types of foods.
Besides, if you’re avoiding fruits, vegetables, legumes, and nuts, you’ll probably just be coming up short on other things your body needs, like fiber, vitamin C, and potassium. It’s easy to over-think things when it comes to food and nutrition, and excluding these foods based on the presence of a single supposed “anti-nutrient” is one more example.