Nutrition Diet: Are All Alliums High in FODMAP?

According to research, fructans, the FODMAP type found in onions and garlic, are among the most common triggers of Irritable Bowel Syndrome (IBS) symptoms. However, the assumption that all alliums are high in FODMAP is a common misconception that can lead to unnecessary dietary restrictions.

Quick Summary

The FODMAP content of alliums varies, with different parts of the plant having different levels of fructans. While garlic and onion bulbs are high-FODMAP, many alliums have low-FODMAP servings, making them safe for sensitive individuals in specific amounts.

Key Points

• Not all alliums are high in FODMAP: The FODMAP content varies significantly across the allium family; some are safe in standard portions, while others are high in fructans.

• The green parts are generally low-FODMAP: The green tops of scallions (spring onions) and leeks contain minimal fructans, making them safe for a low-FODMAP diet.

• Garlic and onion bulbs are high-FODMAP: The white, bulbous parts of garlic and most onions are rich in fructans and typically restricted during the elimination phase.

• Garlic-infused oil is a safe flavor alternative: Fructans do not dissolve in oil, allowing you to get the flavor of garlic by infusing it in oil and then removing the solids.

• Asafoetida provides an onion-like flavor: This spice is a low-FODMAP alternative that offers a robust, savory flavor similar to onion and garlic.

• Processing can lower FODMAP content: Certain methods, like pickling, can reduce the fructan content in alliums as the water-soluble fructans leach out.

• Individual tolerance varies: The reintroduction phase of the low-FODMAP diet is essential to determine your personal threshold for fructan-containing foods.

Understanding FODMAPs and Alliums

FODMAP is an acronym for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols—short-chain carbohydrates that are poorly absorbed by the small intestine. For individuals with a sensitive gut, such as those with Irritable Bowel Syndrome (IBS), these carbohydrates draw water into the large intestine and are rapidly fermented by gut bacteria, causing symptoms like bloating, gas, and abdominal pain.

Alliums like onions and garlic are high in fructans, a type of oligosaccharide. The human body lacks the enzyme to break down fructans, meaning they pass to the large intestine undigested. This fermentation process is what causes digestive distress for sensitive individuals.

The Allium Spectrum: High-FODMAP vs. Low-FODMAP

It is incorrect to assume that all alliums are off-limits on a low-FODMAP diet. The key is understanding that different parts of the plant and preparation methods can significantly alter the FODMAP content.

Alliums to Avoid or Limit

During the elimination phase of a low-FODMAP diet, certain alliums and their components are typically avoided due to their high fructan content:

• Garlic: Both fresh cloves and garlic powder are very high in fructans, and even small amounts can trigger symptoms.
• Onions: This includes most types, such as white, yellow, red, and Vidalia onions. Onion powder is also a potent source of fructans.
• Shallots: These are high in fructans and should be avoided or consumed in very small, tested portions.
• White bulb of scallions (spring onions): The white, bulbous end is high in fructans, unlike the green tops.
• White bulb of leeks: The light-colored bulb of the leek is high in fructans, while the green leaves are safe.

Safe Low-FODMAP Alliums and Alternatives

Fortunately, there are several ways to enjoy allium flavor without triggering symptoms:

• Green parts of scallions (spring onions): The dark green, leafy tops of scallions contain minimal FODMAPs and can be used liberally to add onion flavor.
• Chives: A staple herb in many cuisines, chives have been tested by Monash University and contain no detectable FODMAPs in standard serving sizes.
• Garlic chives: Also known as Asian chives, these flat-leafed herbs have a mild, garlicky flavor and are low in FODMAPs.
• Garlic-infused oil: Fructans are water-soluble but not oil-soluble. This means you can infuse oil with garlic cloves for flavor and remove the cloves before use, leaving the flavor behind without the fructans. It is important to buy certified infused oils or prepare them safely to prevent botulism.
• Leek greens: The green, leafy part of the leek is low in FODMAPs and offers a milder onion flavor.
• Asafoetida (Hing): This pungent spice, popular in Indian cooking, provides an onion-like flavor and is an excellent low-FODMAP substitute. Only a small amount is needed.

Making Sense of FODMAP Content: A Comparison

The table below compares the FODMAP content and usage of common alliums, highlighting the crucial differences between high- and low-FODMAP options based on testing by institutions like Monash University.

Allium Variety	FODMAP Content	Safe Low-FODMAP Serving (approx.)	Preparation/Notes
Garlic Bulb	High in Fructans	No safe serving during elimination	Use garlic-infused oil or alternatives instead.
Onion (Red, White, Yellow)	High in Fructans	Limited to very small amounts; none during elimination	The fructans are water-soluble, so cannot be 'cooked out'.
Scallions (Green Parts)	Low FODMAP	75g (1 ½ cups) per meal	Excellent for adding mild onion flavor. Discard the white bulb.
Leeks (Green Parts)	Low FODMAP	100g (1 cup) per meal	Use the green leafy sections. Discard the high-FODMAP bulb.
Chives	Low FODMAP	5g (standard serving)	No detectable FODMAPs, can be used freely.
Garlic Chives	Low FODMAP	80g (1 cup)	Flat-leafed Asian chive with a garlicky flavor.

How to Reintroduce Alliums into Your Diet

The ultimate goal of the low-FODMAP diet is not to permanently exclude all high-FODMAP foods but to personalize your nutrition plan based on tolerance. After the elimination phase, you can begin the reintroduction phase under the guidance of a dietitian.

1. FODMAP Challenges: Reintroduce high-FODMAP alliums, such as garlic or onions, one at a time over a few days to assess your individual tolerance.
2. Start Small: Begin with a very small portion to see if it triggers symptoms. Your tolerance may vary based on the amount consumed.
3. Monitor Symptoms: Keep a food diary to record which alliums and portion sizes cause digestive distress. Note that cooking methods like pickling can lower fructan levels.
4. Incorporate into Personalized Diet: Once you identify your personal triggers and tolerance levels, you can reintroduce tolerated amounts of alliums back into your diet during the maintenance phase.

Conclusion

While some alliums like garlic and onions are high in fructans, the idea that all alliums are high in FODMAP is a myth. Many alliums and allium products, including chives, scallion greens, and garlic-infused oil, are low-FODMAP and safe for consumption by individuals with sensitivities. By understanding the specific FODMAP content and being mindful of portion sizes, those on a low-FODMAP diet can continue to enjoy the flavor and nutritional benefits of these diverse vegetables without compromising their digestive comfort. For personalized guidance on incorporating alliums and navigating the low-FODMAP diet, it is always recommended to consult with a registered dietitian.

Practical Tips for Cooking with Alliums on a Low-FODMAP Diet

• Use the green parts of scallions or leeks to build a savory, onion-like flavor base for soups, stews, and sauces.
• Sauté with garlic-infused oil to impart a delicious garlic flavor without the fructan content.
• Experiment with asafoetida (hing) in place of onion or garlic powder for a potent, low-FODMAP flavoring.
• Add fresh chives or garlic chives as a garnish to finished dishes to brighten the flavor.
• Explore pickled alliums, as the fructans can leach out into the liquid, lowering their FODMAP content.

Final Takeaway on Alliums and FODMAPs

In essence, a low-FODMAP diet doesn't mean a flavorless existence. By selecting the right alliums and preparing them in specific ways, you can ensure a nutritionally diverse and delicious diet, even with a sensitive gut. Focus on the green parts, use infused oils, and consider effective alternatives to keep your meals savory and satisfying.

• Start with low-FODMAP parts: Utilize the green tops of scallions and leeks for a safe, mild onion flavor.
• Use infused oil for flavor: Since fructans are water-soluble but not oil-soluble, garlic-infused oil is a safe way to add garlic flavor.
• Embrace alternatives: Spices like asafoetida offer a potent onion-like flavor profile that is low in FODMAPs.
• Portion size matters: Small, measured portions of some high-FODMAP alliums, or processed versions like pickled onions, may be tolerated during the reintroduction phase.
• Test your tolerance: The low-FODMAP diet is a three-phase process. Reintroducing foods is key to finding your personal tolerance level.

For additional resources, consult the Monash University FODMAP Diet website for the most up-to-date guidance.

Frequently Asked Questions

Is regular garlic high in FODMAPs?

Yes, fresh garlic cloves, garlic powder, and fermented black garlic are all considered high in fructans, a type of FODMAP, and are typically avoided during the elimination phase of the diet.

Can I use garlic-infused oil on a low-FODMAP diet?

Yes, garlic-infused oil is a safe alternative. Fructans are water-soluble, not oil-soluble, so the flavor infuses into the oil without the problematic carbohydrates. Ensure you remove all solids or buy a certified product.

Are chives and garlic chives low in FODMAPs?

Yes, both chives and garlic chives are low in FODMAPs. Standard servings have been tested and contain minimal or no detectable fructans, making them safe for sensitive individuals.

What parts of a leek are low-FODMAP?

Only the dark green, leafy tops of leeks are low in FODMAPs and safe to eat. The white and pale green bulb section is high in fructans and should be discarded.

What parts of a scallion (spring onion) are low-FODMAP?

The green, leafy part of the scallion is low in FODMAPs, while the white bulb is high. The green parts can be used freely to add flavor.

Can cooking destroy the fructans in onions or garlic?

No, cooking does not effectively remove fructans from high-FODMAP alliums. Fructans are water-soluble and will leach into the rest of the dish. Alternatives like infused oil or low-FODMAP alliums must be used.

What is a good alternative to onion powder?

Asafoetida, or 'hing', is an excellent low-FODMAP alternative to onion and garlic powder. It has a strong, savory flavor and only a small pinch is needed.