The Scientific Reason Garlic Is High in FODMAPs
Garlic is a member of the allium family and contains a high concentration of fructans. Fructans are a type of oligosaccharide, which is a group of short-chain carbohydrates that the human body cannot properly digest. Unlike other carbs, fructans pass through the small intestine largely unabsorbed, traveling to the large intestine where they are fermented by gut bacteria.
This fermentation process produces gas, which can cause uncomfortable symptoms like bloating, cramping, and abdominal pain in individuals with a sensitive digestive system, such as those with IBS. For this reason, garlic is typically eliminated during the initial, restrictive phase of a low FODMAP diet. Monash University, a key authority on the low FODMAP diet, has extensively tested garlic and confirms its high fructan content.
Forms of Garlic and Their FODMAP Content
It's important to understand that the FODMAP content of garlic is not limited to its raw form. Many common garlic products are also high in fructans and should be avoided during the elimination phase of the diet.
- Fresh Garlic: A single clove contains enough fructans to trigger symptoms in sensitive individuals.
- Garlic Powder: Because it's made from dehydrated garlic, garlic powder is a concentrated source of fructans and should be strictly avoided.
- Black Garlic: This is fermented garlic, and laboratory tests show it also contains high levels of fructans and fructose.
- Garlic Salt: Since this product contains garlic powder, it is also high in FODMAPs.
The Cooking Myth: Removing Garlic Cloves
A common misconception is that you can cook with whole garlic cloves and simply remove them before eating the meal. This approach does not work for water-based dishes like soups or sauces because fructans are water-soluble. During cooking, the FODMAPs leach out of the garlic and infuse into the liquid, making the entire dish high in FODMAPs. While you can remove the solids, the problematic carbohydrates will remain in your food.
Low-FODMAP Alternatives for Garlicky Flavor
Giving up garlic doesn't mean sacrificing flavor. Thanks to the science of FODMAPs, there are several ways to enjoy the aroma and taste of garlic without the unpleasant side effects.
Use Garlic-Infused Oil
This is the most popular and effective way to achieve garlic flavor on a low FODMAP diet. Since fructans are not oil-soluble, infusing oil with garlic transfers the flavor compounds without the fructans. You can buy certified low FODMAP garlic-infused oil or make your own at home. The key is to strain out all solid garlic pieces before using the oil.
Add Safe Herbs and Spices
Several herbs and spices can mimic or complement the flavor of garlic:
- Asafoetida (Hing): This Indian spice imparts a garlicky, savory flavor when bloomed in hot oil. Look for brands without wheat flour fillers.
- Chives and Garlic Chives: The green parts of chives are low in FODMAPs and can be used generously. Garlic chives offer a stronger garlic note.
- Spring Onion Greens: The green, leafy part of a spring onion (scallion) is low FODMAP. Just avoid the white bulb.
- Garlic Scapes: These green, curly stalks that grow from hardneck garlic have a milder flavor and are low FODMAP in smaller servings.
- Pickled Garlic: As of recent testing, one clove of pickled, drained garlic is low FODMAP, as the fructans leach into the vinegar.
High-FODMAP Garlic vs. Low-FODMAP Alternatives
| Feature | High-FODMAP Garlic | Low-FODMAP Garlic-Infused Oil |
|---|---|---|
| Form | Fresh bulb, powder, black garlic, salt | Pure oil infused with garlic flavor |
| FODMAP Content | High in fructans | No fructan content |
| Cooking Method | Infuses water-based sauces and broths with fructans, causing symptoms | Safely adds flavor to cooked dishes and dressings, no fructans |
| Use | Avoid during elimination phase of low FODMAP diet | Use freely for flavor during elimination phase |
Navigating the Reintroduction Phase
Following the elimination phase of the low FODMAP diet, you will begin the reintroduction phase, testing different FODMAP groups, including fructans, to determine your personal tolerance. You can test garlic tolerance by gradually increasing the serving size, starting with a very small amount, and monitoring your symptoms. Some people find they can tolerate small amounts of garlic, while others cannot. Learning your individual triggers is the goal of this phase.
To learn more about the low FODMAP process, consult the definitive source at the Monash University FODMAP blog.
Conclusion
In summary, fresh, powdered, and black garlic are high in fermentable fructans, making them problematic for individuals with IBS and FODMAP sensitivities. While the cooking myth of removing whole cloves from watery dishes is ineffective, safe alternatives abound. Garlic-infused oil is the perfect substitute for achieving that savory flavor, while other options like asafoetida, chives, and garlic scapes can also be used. By understanding the science and using smart substitutions, you can continue to create delicious, gut-friendly meals without compromise.
