Introduction
Vegetables are an essential part of our diet. They contain many vital nutrients. They have been grown and consumed by humans for thousands of years. Vegetables not only meet our nutritional needs, but also the nutritional needs of the intestinal flora, i.e. the trillions of microscopic bacteria, viruses and yeasts that live in our intestines.
Our gut flora relies heavily on vegetables to meet its nutrient needs. The amount and type of vegetables we eat control the growth and composition of our gut flora. In this way, our diet and vegetable consumption determine the composition of our gut microbiota.
As scientists have deciphered the numerous benefits of eating vegetables, plant-based diets are becoming increasingly popular these days. In particular, they are recommended for the prevention of many diseases such as heart disease, diabetes and cancer.
However, some vegetables can also have undesirable effects on some people. For example, some vegetables can contribute to intestinal diseases. This can be direct, as in the case of allergies, or indirect, by altering the composition of the intestinal microbiota, as in the case of functional bowel problems such as constipation and irritable bowel syndrome (IBS).
People with IBS may not tolerate some vegetables, especially if they are experiencing a flare. Some vegetables may even trigger a flare in some people with IBS. Below, we explore the role of vegetables in IBS. We also list vegetables you should avoid if you have IBS.
FODMAP: The connection between vegetables and IBS symptoms
How vegetables affect our intestines and the symptoms of IBS has been studied in detail. In addition to nutrients, vegetables also contain some other components that can be fermented by gut microbes. These fermentable components of vegetables are summarized by the acronym FODMAP, which stands for fermentable oligosaccharides, disaccharides, monosaccharides and polyols.
The FODMAP compounds are a type of carbohydrate. These fermentable carbohydrates are poorly absorbed into our blood. On the contrary, they are appreciated by the intestinal microbes as a source of food. When FODMAP compounds are finally digested by the intestinal microbes, most people experience severe gas formation in the intestines.
The excess gas produced by fermentation of FODMAP foods can cause a feeling of fullness in the intestines (flatulence). It can also cause pain in the abdomen. In some people, it can trigger strong intestinal movements that lead to diarrhea and cramps. So we can say that FODMAP are the link between vegetables and IBS symptoms.
Moreover, the effects of a diet rich in FODMAPs are not limited to IBS symptoms. Regular consumption of foods and vegetables high in FODMAPs can also lead to an overgrowth of gut microbes, which promotes inflammation in the gut and many other health problems. Thus, a diet high in FODMAPs can be considered pro-inflammatory.
In contrast, a diet low in FODMAP vegetables may be beneficial for people with IBS, especially during an IBS flare-up. A diet of low FODMAP vegetables can reduce gas formation in the intestines and even reduce the growth of gas-producing microbes. This can reduce IBS symptoms and intestinal inflammation. Thus, the low FODMAP diet can be considered a therapeutic and anti-inflammatory diet for people with IBS.
Vegetables with high FODMAP content that you can avoid in irritable bowel syndrome
Vegetables high in FODMAP are among the worst triggers for IBS. The 10 vegetables that trigger IBS the most include bulb vegetables (onions and garlic), seed vegetables (beans, lentils, and peas), flower vegetables (broccoli, cauliflower, and artichokes), and stem vegetables (asparagus and potatoes). These ten vegetables are rich in fermentable FODMAP compounds. It is best to avoid them in IBS, especially during an episode.
However, this list of the top 10 FODMAP-containing vegetables contains some limitations. First, this list is not a complete list of FODMAP-rich foods. Also, the composition of the gut microbiota may be different in different people, and a vegetable that causes IBS symptoms in one person may not necessarily cause them in another.
In addition, avoiding vegetables high in FODMAPs should only be temporary. The goal of eliminating FODMAP-rich vegetables from the diet of a person with IBS is to provide temporary relief. One cannot go without these important nutrient-dense vegetables forever. However, it can be difficult to identify the problematic vegetables. Until you add each of these vegetables back into your diet after eliminating them, you do not really know which one is actually causing your IBS symptoms.
You should also keep in mind that vegetables are not the only source of FODMAP-rich foods. There are numerous other offenders on the list of non-vegetable foods high in FODMAPs, including wheat, fried foods, dairy, processed foods, caffeine, artificial sweeteners, chocolate, and alcoholic beverages. Many of these foods are certainly among the 10 worst foods for people with IBS.
Low FODMAP vegetables that you can consume in irritable bowel syndrome
Another interesting question is what vegetables people with IBS can eat, especially during an episode of the disease. The answer is simple. Most "fruiting vegetables" such as cucumbers, eggplant, okra, corn, and tomatoes can be tolerated by most people with IBS. Root vegetables such as radishes, carrots and beets are also generally well tolerated.
The reason these vegetables are better tolerated is because of their composition. They are rich in soluble/absorbable carbohydrates and contain very few fermentable FODMAP carbohydrates. For green leafy vegetables, things are a bit more complicated. Some of them, like spinach, can be high in FODMAPs, while others, like lettuce, are low in FODMAPs.
Conclusion
Vegetables are an essential part of our diet. But those with high FODMAP content may be involved in IBS and intestinal inflammation. Here we have answered the question of why some vegetables trigger IBS, in relation to their ability to be fermented. Fermentable vegetables (high in FODMAP) should be temporarily omitted during IBS to control symptoms and speed recovery.
There are alternative low FODMAP vegetables that do not cause bloating and are non-inflammatory; their consumption can be increased to provide important nutrients and support IBS healing during IBS. Although we have provided the list of the top 10 foods and vegetables for IBS, speaking with a nutritionist or dietitian can help create a customized diet plan for IBS.
References
https://www.hopkinsmedicine.org/health/wellness-and-prevention/fodmap-diet-what-you-need-to-know
https://www.healthline.com/health/digestive-health/foods-to-avoid-with-ibs
https://www.britannica.com/topic/vegetable
