Managing digestive distress, such as that experienced by individuals with Irritable Bowel Syndrome (IBS), often involves specialized dietary changes. The Low FODMAP diet is an effective approach to identify and reduce foods that trigger uncomfortable gut symptoms. Navigating the rules of this diet can be confusing, especially when common ingredients like green onions are involved. This article clarifies the specific FODMAP content of green onions (scallions) and provides guidance for incorporating their flavor safely into meals.
Understanding FODMAPs and the Diet
FODMAP is an acronym for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols. These are short-chain carbohydrates that the small intestine poorly absorbs in some individuals. Instead of being absorbed into the bloodstream, these molecules travel to the large intestine where gut bacteria rapidly ferment them.
This fermentation generates gases, like hydrogen, which can lead to bloating and abdominal pain in people with a sensitive gut. The poorly absorbed carbohydrates also draw extra water into the intestinal tract, contributing to diarrhea. The Low FODMAP diet is a temporary, three-step process designed to restrict these compounds to reduce symptoms and then systematically reintroduce them to determine personal tolerance.
Green Onions: Distinguishing Low and High FODMAP Parts
Green onions (scallions or spring onions) present a unique situation on the Low FODMAP diet because their FODMAP content is not uniform throughout the plant. The problematic compounds in alliums are fructans, a type of oligosaccharide. Fructans are concentrated in the white bulb of the green onion, making this portion strictly high FODMAP.
The green, leafy tops of the plant contain negligible amounts of fructans. The dark green parts are considered low FODMAP and can be safely consumed, even during the most restrictive phase of the diet. To prepare them safely, the white bulb and the pale green section where the color begins to lighten must be completely removed and discarded.
Monash University confirms that a standard serving size of the green tops is low FODMAP. This allows individuals to use the green tops as a garnish or cooked ingredient to add a mild onion flavor without triggering digestive symptoms. Only the vibrant green sections should be used, as the fructan content increases rapidly closer to the bulb.
Practical Low FODMAP Allium Alternatives
Completely avoiding the intense flavor of onions and garlic can be challenging, but several practical alternatives exist to retain flavor in cooking. One option is to use the green parts of other alliums, such as the green leaves of leeks and chives. Chives are inherently low FODMAP and deliver a mild onion-like taste, making them a suitable substitute in many recipes.
A particularly effective method for adding allium flavor without fructans is the use of infused oils. Fructans are water-soluble but not soluble in fat or oil. This allows the aromatic flavor compounds from high-FODMAP ingredients like garlic and the white part of onions to be extracted into oil, leaving the carbohydrates behind.
When making or purchasing an infused oil, the solid pieces of garlic or onion must be completely strained out before use to ensure the oil remains low FODMAP. These infused oils can be used as a flavorful base for sautéing and are often commercially available. Another simple alternative is using a small amount of asafoetida powder, a spice that provides an onion-garlic flavor profile when cooked.