FODMAPs and Gut Sensitivity

(Part 1 of the Food Sensitivity Series)

FODMAP is not a word from a Dr. Suess book, but an acronym for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, And Polyols.  These complicated-sounding compounds are types of carbohydrates that frequently cause gastrointestinal (GI) distress.  Fermentable oligosaccharides are sugars strung together to create undigestible “resistant” starches; disaccharides and monosaccharides are double and single sugars, respectively; and polyols are sugar alcohols.  When these molecules are not absorbed in the upper GI tract, they move into the colon and are broken down by the resident microbes.  Gut fermentation leads to the production of gas resulting in bloating, distension, flatus (farts), and sometimes cramping.  Some of these fermentation products also draw water into the colon, leading to diarrhea.  FODMAPs exacerbate irritable bowel disease by aggravating the stretch sensors with bowel inflation.

 You may recognize foods in the list below that you’ve already associated with gastrointestinal distress.  Fructans and galactans are both fermentable oligosaccharides, lactose (milk sugar) is a disaccharide, and fructose (fruit sugar) is a monosaccharide. 

*****FODMAPs*****

FRUCTANS:  *Wheat, rye, barley, onions, garlic, shallots, leeks, scallions, chicory, artichokes, asparagus, cabbage, Brussels sprouts, broccoli, cauliflower, kohlrabi, fennel, Jerusalem artichokes, pawpaw, persimmons *Inulin, used as a fiber source in processed foods

GALACTANS:  *Beans, chickpeas, lentils, peas, soybeans. (tempeh and green beans, not as much) *Some seaweeds Carrageenan, an algae-based thickening agent used in many processed foods

LACTOSE:  *Milk, ice cream, cream, soft unripened cheeses (less so in yogurt, buttermilk, and more aged cheeses)

FRUCTOSE:  *Most fruits, especially apples, pears, grapes, kiwi, lychees, mangos, and watermelon *Sugar snap peas, sweet corn, sweet onions, and red bell pepper *High-fructose corn syrup (HFCS), honey & agave syrup (often used in cocktails) *Fruit juices, applesauce, jellies, jams, preserves, and dried fruits like raisins and prunes *Soda pop sweetened with HFCS Ketchup and other sauces made with HFCS

POLYOLS:  *Apples, pears, quince, stone fruit (peaches, nectarines, cherries, apricots, plums, prunes), blackberries, figs, lychees, watermelon *Avocados and mushrooms *Sugar-free sweetening agents: sorbitol, erythritol, mannitol, xylitol, and maltitol (found in sugar-free baked goods, jams, frozen desserts, candies, and chewing gum)

How one responds to FODMAPs falls on a spectrum.  Some people are seemingly unbothered by these foods, others bothered by only a few, and some unlucky souls are sensitive to many.  Eating a lot of one favorite food on this list or combinations of FODMAP-containing foods can trigger GI unhappiness.

While onions, garlic, and cabbage have a reputation for not agreeing with some folks, other members of the fructans group fly under the radar.   Wheat, barley, and rye contain fructans as well as gluten, which is more often blamed for GI distress.  To complicate matters, other FODMAPs are often added to wheat-containing dishes like pasta and pizza.

Beans and lentils are notorious for causing gas.  Draining the soaking water from dried beans and rinsing canned beans thoroughly before cooking will remove some of the galactosides which cause discomfort. Moreover, be aware that some vegan desserts and faux whipped toppings are made with aquafaba, the fluid surrounding canned chickpeas or beans.  To (perhaps) better tolerate legumes, you can try an over-the-counter enzyme product like Beano® or another alpha-galactosidase pill while eating them.

Lactose intolerance develops after childhood and occurs in roughly two-thirds of adults.  Most infants can digest this milk sugar, but as they age, the gut’s lactase enzyme activity lessens.  Except for some people with northern European heritage, most adults lose the enzymatic capability to digest lactose to varying degrees.  Some may be able to tolerate cultured milk products like yogurt, buttermilk, and aged cheeses where lactose is partly reduced, but others may not.  Fortunately, lactase enzyme tablets like Lactaid® and lactose-free products treated with the lactase enzyme have made it possible for many to enjoy ice cream, cottage cheese, and other dairy products again. 

Fructose is very sweet, but incompletely absorbed by the gut. Chemically bound 50:50 with glucose, it forms sucrose, or table sugar.  If you want to reduce fructose intake, begin by avoiding processed foods made with fructose, high fructose-containing syrup (HFCS), and sugar: soda pop, juice drinks, sauces, syrups, baked goods, and other sweet treats.  Additionally, agave syrup has a very high fructose content and honey is somewhat more than 50% fructose.

Fresh fruits obviously contain fruit sugar, but also provide fiber, vitamins, minerals, and beneficial phytochemicals, so eat them judiciously, noticing which are better tolerated. Typically, riper fruit has more fructose.  Berries and citrus (lemons, limes, oranges, and grapefruit) contain lesser amounts of fructose and may be better tolerated. 

Polyols are found naturally in some fruits and food processors use natural or synthesized polyols as sugar-free sweeteners.  Again, since fruits have beneficial nutrients, eat smaller portions of whole or cut-up fresh fruit.  Fruits that are also on the fructose list might be good choices for initial restriction when sensitivities are being sorted out. 

Read ingredient lists to discover whether polyols might be present as non-sugar sweeteners; in general, their names end in “-ol.”.  (See above list.) They may be the only source of sweetness in sugar-free products like gum, candies, jams, and other desserts or may be added to balance out the “flavor” of other non-caloric sweeteners like sucralose, monk fruit, and stevia in other calorie-controlled foods and beverages.

It can be tricky to discover which FODMAPs might be causing discomfort.  For guidance, ask your doctor for a referral to a registered nutritionist or dietician They will review your diet history and look for patterns.  If FODMAPs are a possible cause of your GI distress, most will recommend eliminating one or more FODMAP foods or food groups from your diet for 2 or more weeks to see if your symptoms diminish.  Foods are then reintroduced one at a time to look for sensitivity.  In some cases, there may be a “dose-related” relationship where one can tolerate small amounts, but not large helpings.  No surprise, stopping all FODMAPs altogether is not recommended since complex carbohydrates and oligosaccharides are still important food sources for both you and your beneficial gut microbes.