Why Spices Can Trigger Symptoms And How We Do It Differently

Onion and garlic are two of the biggest FODMAP triggers and two of the hardest ingredients to replace. They're the base of so many dishes that cutting them out can leave food tasting flat, even when the rest of the recipe is spot on.

The good news: there are substitutes that genuinely work, not just "leave it out and hope for the best." Here's what actually holds up in the kitchen.

Why Onion and Garlic Are So Hard to Replace

Onion and garlic aren't just flavour they're aromatic bases that a huge number of savoury dishes are built on. They contain fructans, a type of FODMAP that even small amounts can trigger symptoms for, which is why "just use less" doesn't usually solve the problem the way it does with other ingredients. According to Monash University's FODMAP research team, who developed the low FODMAP diet, fructans are poorly absorbed in the gut and can trigger symptoms even at low serving sizes — which is echoed in our own blog on why spices can trigger symptoms, and how we do it differently.

What Actually Works as a Substitute

The green tops of spring onions (scallions) The green part of a spring onion is low FODMAP in normal serving sizes (it's the white bulb that's high FODMAP), a distinction confirmed by the Monash FODMAP food database. Finely sliced, it adds a mild onion flavour and works well raw as a garnish or cooked briefly at the end of a dish.

Garlic-infused oil Garlic is high FODMAP because the fructans are water-soluble, not oil-soluble. This means garlic-infused oil carries the aroma and flavour of garlic without the FODMAP content, as long as the garlic solids themselves are strained out and not left in the oil.

Asafoetida (hing) A pungent spice used in Indian cooking, asafoetida delivers a savoury, onion-garlic-like flavour when cooked briefly in oil. A small pinch goes a long way, and it's a staple low FODMAP swap for curries and lentil dishes.

Chives Chives are FODMAP Friendly certified in normal serving sizes and bring a mild oniony flavour, particularly good raw as a finishing herb.

Pre-made low FODMAP spice blends This is where a lot of people land eventually  rather than trying to recreate onion and garlic flavour ingredient by ingredient every time, a blend designed to replace that savoury base does the work for you. Our Essential Herbs blend is built exactly for this an everyday, onion and garlic-free seasoning for pastas, roasts and weeknight meals. It's the difference between cooking "around" a limitation and just cooking a meal that tastes complete.

What Doesn't Work

• Onion or garlic powder in small amounts - FODMAPs don't cook out, and even small quantities can trigger symptoms for sensitive individuals.
• "Low FODMAP" garlic salt blends without certification - always check for genuine testing or certification, as "low FODMAP" claims aren't regulated the same way as gluten-free labelling. Look for the FODMAP Friendly certification mark, which is backed by independent lab testing.
• Simply omitting them with no replacement - this is usually what leads to bland, "diet food" style cooking, and why so many people give up on low FODMAP eating being enjoyable.

The Bottom Line

You don't have to choose between avoiding your triggers and enjoying full-flavoured food. The right combination of infused oils, spring onion greens, and a well-built spice blend can get you most of the way back to the flavour you're used to  without the aftermath. If you're building out a full low FODMAP pantry, our grocery list guide covers what else to stock up on, and what to leave on the shelf.

Explore our low FODMAP spice blends: Essential Herbs · Green Fusion · Mexican Spice