Ingestion of some foods can cause abdominal swelling and because of fermentation of some substances contained in them, gas is formed. Dr. Manuela Pastore, dietician of Humanitas, spoke about this topic in an interview with Corriere della Sera.

An example of this is the so-called FodMap, a term that designates sugars that can cause swelling. F stands for fermentable (carbohydrates that produce gas), O for oligosaccharides (like those found in legumes), D for disaccharides (an example is lactose), M for Monosaccharides (like fructose) and finally P for Polioli (sorbitol and mannitol, artificial sweeteners). For example, it is recommended that patients with irritable bowel (who therefore also suffer from abdominal swelling) do not consume foods containing these components.



“The meteorism linked to the consumption of legumes and other vegetables is often due to the fact that our intestines have become accustomed to very refined foods and they are uninhabited to fiber. When faced with foods rich in fiber, it reacts abnormally, fermenting, swelling the belly with air and slowing down digestion. Therefore, legumes should be introduced initially in one meal per week, starting with small tastings and gradually increasing frequency and quantity. It is better to choose quality dried legumes avoiding the precooked ones in a box: lentils and peas are already peeled ready for cooking, while the others should be left to soak for 12 hours, changing the water a couple of times, in order to soften them as much as possible. The water used to boil them should not be the same as that used for soaking, no salt should be added, but a pinch of bicarbonate to make them softer and lighter. You can also add carminative herbs that avoid fermentation, such as bay leaves, fresh ginger, savory and mint. If swelling continues over time, we recommend that you only choose lentils, especially red ones, because they are more digestible,” says Dr. Pastor.


Cruciferous vegetables

Cruciferous species such as cabbage, cauliflower, broccoli, Brussels sprouts, savoy cabbage, turnips, radishes, can cause fermentation and swelling. However, these foods are valuable to our diet, so it is important not to give them up. “These are mostly vegetables typical of the winter season, precious because they are rich in vegetable compounds, sulforaphane and indole-3-carbinol with antitumor action, antioxidants, B vitamins, potassium and calcium. In people with particularly sensitive or malfunctioning intestines, they should be consumed in small portions and not more than once a week. To facilitate digestion, we need to reduce fat by reducing seasonings, choose protein foods with low fat and limit carbohydrate portions of that meal”.


Fruit: pay attention to apples

Apples, plums and raisins are the fruits that most commonly cause swelling. “This fruit contains fructose, fructans and polyols, short-chain carbohydrates that can cause some problems for people with irritable colon or digestive problems. Sugars and fibers ferment, stimulating the production of gases such as hydrogen, methane and carbon dioxide that cause swelling, meteorism, cramps up to diarrhea or constipation. It can be useful to eat them slowly while drinking a warm fennel or lemon balm herbal tea to limit the unpleasant effect and relax the muscles of the digestive system,” the specialist advises.


What if I am lactose intolerant?

Lactose may not be digested due to a lactase deficiency, the enzyme necessary to breakdown lactose, resulting in swelling. “If lactose intolerance has been correctly diagnosed, the simplest alternative is to use lactose-free milk and dairy products. These foods have the same nutritional properties as the lactose versions, including the calcium, vitamin D and fat content, with lactose already broken down into two simple sugars: galactose and glucose, free to be absorbed without creating intestinal problems. Parmesan cheese with a maturation period of more than 30 months is highly digestible, since lactose is completely fermented. Yoghurt contains very low lactose percentages and it is therefore better tolerated than milk. Lactose intolerance is often never absolute and small amounts distributed throughout the day are better tolerated than large amounts introduced into a single meal. Vegetable milk and tofu are the completely lactose-free alternatives,” concludes Dr. Pastore.