Does lectin in vegetables make you sick? A new diet describes almost all types of vegetables as harmful because they contain the protein substance. We took a closer look at the nutrition trend.
Lectin – the indigestible protective shield of plants
Lectins are protein compounds found in pretty much all plants and animals. Their tasks are very different – however, some plants have developed special lectins that are supposed to protect them from predators: If humans or animals eat these plants, the indigestible proteins enter the body via the intestine. The effects vary greatly depending on the type of lectin: most often they cause headaches, vomiting, or diarrhea – others can even be fatal. They can also influence our metabolism, for example by encouraging the body to store more fat in the cells.
Nevertheless, the plant substance does not have to be dangerous: In an MDR report, nutritionists give the all-clear – most lectins break down when exposed to heat. So they are harmless in cooked vegetables.
The American heart surgeon Dr. However, Steven Guntry believes the lectin in our food is the root cause of many diseases. He sees a connection between the substances and obesity, heart attacks, diabetes and gastrointestinal disorders.
Lectin-free diet: These foods are both forbidden and allowed
What’s left is a short list of lectin-free foods:
The basis is a lot of lettuce, green leafy vegetables and vegetable oils. Cabbage, fennel, asparagus or seaweed are also permitted.
Some seasonal fruit is allowed for a change. dr Guntry recommends buying fruit only when it is in season, because that is when the most naturally ripe fruit is sold. He takes a critical view of airborne goods: Here the fruit is often harvested too early and then ripened with chemicals – as he writes in his book. The lectin content is therefore higher.
Meat, poultry or fish, on the other hand, should only be eaten rarely. dr Gundry recommends wild animals or animals that are not fed concentrates. The additional feed often consists of soybean oilseed and contains lectin, which should also accumulate in the meat of the animal.
Compared to the permitted foods, the prohibited list is much longer and includes, among other things:
Many cereals, rice, soy or potatoes
Beans, peas and lentils
Lots of vegetables including tomatoes, peppers and cucumbers
Most types of nuts
Lectin in Vegetables: Does it Really Make You Sick?
Extensive research reports on lectin in food have existed for decades. However, we have known for a long time how to deal with the substances: Traditional recipes explain how to prepare vegetables in a healthy way – this way we can easily render lectins and other food toxins harmless.
One example, which MDR also reports, are red runner beans: like all legumes, including peas and soybeans, they contain the lectin phasin. This substance causes our blood to clot – so just a few fire beans can be deadly. Cooked well, however, they are completely harmless. The one from Dr. So Guntry’s forbidden vegetables are easy to detoxify.
So why the strict ban?
dr Guntry sees lectin as a trigger for autoimmune diseases such as diabetes, arthritis, asthma, rheumatism, celiac disease and Alzheimer’s. He assumes that residues that we ingest with food thicken our blood and accumulate in various places in our body. Whether his thesis is correct is disputed. Some studies support his views that lectins can be harmful to the human body and suggest a link to rheumatism. Other results seem to prove the opposite: they show how vegetables can be used to treat diseases such as cardiovascular disease or diabetes and also help to reduce weight. In addition, according to the German Society for Nutrition, vitamins and fiber in vegetables are an important part of a healthy diet.
It has also been proven that a change in diet or a diet in which only very few foods are allowed for a short time is good for the body. It represents one of the foundations of Indian Ayurveda or traditional Chinese medicine (TMC), which is also supported by current researchers at the Imanuel Clinic in Berlin and the Karl and Veronika Carstens Foundation.
But beware: These restrictive diets are therapies for diseases and should not be permanent nutritional recommendations.
This is also the conclusion of the experts in the MDR report: As long as you don’t have any symptoms, eat as much fruit and vegetables as you want and what you like. Just pay attention to the correct preparation and the organic quality of the products.
Special case: lectin in wheat
dr Guntry tested how his body reacts when he eats whole grain cereals, lots of fruit and vegetables. According to his own statements, he soon gained weight, his cholesterol level and high blood pressure rose.
How can that be? In the MDR, the experts emphasize that everyone has an individual metabolism and therefore reacts differently to food. Research on wheat lectin is also contradictory: US researchers examined the effect of wheat lectin on metabolism. They report that lectin promotes increased fat storage in the cells via the insulin receptors – but the British Medical Journal reports on the health benefits of whole grains – and that it protects against obesity, among other things.
So should you eat whole grains, right? Perhaps it helps to know that not all whole grain products contain the same amount of lectin: MDR experts admit that large quantities of incorrectly processed whole grain can be harmful. The heat in the oven cannot harm the wheat lectin, only the usual fermentation in old bread recipes decomposes the lectin. Thus, traditionally made bread should contain less lectin than industrially manufactured baked goods.
