Another year, another food fad. Depending on what you read these days, it can seem like every food will make you ill. We are used to dairy and gluten-containing foods being described as toxic, but the newest diet claims that it is lectins in foods we should be worried about. The Lectin Free Diet has been referred to as ‘the next gluten‘ by some articles.
Awareness of lectin has reached the public in part due to the publication of ‘The Plant Paradox’, a New York Times bestseller by Dr Steven Gundry, MD. Dr Gundry believes that lectins are responsible for altering the gut microbiome and making people vulnerable to a range of autoimmune diseases, from rheumatoid arthritis to Crohn’s disease.
What are lectins?
Lectins are carbohydrate-binding proteins found in many plants and animals, particularly pulses, grains and seeds. They are also found in nightshade vegetable such as eggplant, potatoes and tomatoes. Their role in plants is unknown, however some scientists believe lectins function as a deterrent to being eaten by animals or insects, as they can cause illness and death by binding to body cells in the gut.
Should we avoid them?
When it comes to lectins, the total amount eaten at one time is important- most people only consume lectins in small amounts, which do not cause them any side-effects. Certain foods are higher in lectins, for example, there are high levels of a type of lectin called phytohaemagglutinin in raw kidney beans which is can cause symptoms such as nausea or diarrhea if eaten. Many other foods contain lower levels of lectins which do not appear to cause issues when eaten.
Another important thing to note is that several of our cooking methods reduce amount of lectins in the food. Soaking and fermenting foods, and cooking at a high temperature, all reduce the lectin content of the food. As we cook most of our food, the chances of someone eating enough lectins to cause issues is low, unless they are on a raw food diet.
It’s important to remember that most of the foods which contain lectins also contain healthy substances, such as fiber, minerals, vitamins, and phytochemicals which have been shown to reduce disease risk, including cancer risk. For example, whole-grains, tomatoes and legumes are all listed on the American Institute for Cancer Research’s Foods That Fight Cancer list. There is no limited evidence that lectins cause issues in humans, but there are a wealth of studies showing associations between lectin-containing foods and good health. For example, a higher intake of whole-grains is linked to reduced risk of cardiovascular disease, heart disease and death, while eating pulses has been shown to help with weight loss and lowering cholesterol.
The Lectin Free diet is another example of focusing extensively on one nutrient when it may not be warranted. At the moment, there is no strong evidence showing that lectins harm us. We do know from extensive studies that eating lectins containing foods (such as pulses) is associated with a more healthy life, including reduced risk of cancers, heart disease, stroke and increased likelihood of being a healthy weight. If you haven’t experienced issues related to these foods, it would seem unwise to cut them out unnecessarily.
For most people, lectins are not substances which we have to worry about. If you are having digestion issues, it is best to speak to a registered dietitian, as it may be that you have intolerance to other components in food (for example FODMAPS). Having a consultation with a professional will allow them to pinpoint where your issues are, to avoid unnecessary eliminations.