Does Lettuce Worsen Symptoms of Irritable Bowel Syndrome?

Lettuce contains fiber, which is a common trigger for many people with IBS.

Fiber is either soluble or insoluble based on whether it dissolves in water. Soluble fibers can be further divided into (2):

• Viscous or nonviscous: based on whether they form a gel in your gut
• Fermentable or nonfermentable: based on whether your gut bacteria can break them down
• Short- or long-chain: based on the length of their chemical structure

Historically, diets rich in soluble fiber and low in insoluble fiber were thought to best manage IBS (3).

However, this recommendation is now considered outdated because it doesn’t consider the fact that most plants contain both soluble and insoluble fiber. Moreover, it fails to take into account that various soluble fibers tend to affect IBS differently.

For instance, fermentable soluble fibers, such as inulin and beta glucan, may worsen IBS symptoms. On the other hand, nonfermentable soluble fibers like psyllium may relieve symptoms (3, 4).

Lettuce contains less than 1 gram of fiber per cup (49 grams), the majority of which is insoluble. This is significantly less fiber than the amount found in the same volume of most other vegetables.

The amount of insoluble fiber you can tolerate varies from one person to another.

That said, this small amount of fiber is unlikely to trigger symptoms in most people with IBS. In fact, due to its low fiber content, lettuce may be a good option for people with this condition who have trouble tolerating fiber-rich vegetables.

SUMMARY

Lettuce contains a very small amount of fiber, most of which is insoluble. This type of fiber may trigger or worsen IBS symptoms in some people, though the very small amount in lettuce is unlikely to do so.

Fermentable oligo-, di-, mono-saccharides, and polyols (FODMAPs) are short-chain, soluble, and highly fermentable fibers.

When digested, FODMAPs release gas into your gut more quickly than it can be absorbed into your blood for elimination through your lungs (3).

This imbalance is thought to cause the pain, discomfort, bloating, and gas so often experienced with IBS (2, 3).

Research suggests that a low FODMAP diet may provide relief from IBS symptoms (3, 5).

Lettuce is made up almost exclusively of insoluble fiber. Therefore, it’s considered a low FODMAP food — and a good alternative to high FODMAP vegetables, such as artichokes, cabbage, broccoli, beets, Brussels sprouts, and asparagus (3).

SUMMARY

High FODMAP foods may trigger or worsen IBS symptoms. Lettuce contains negligible amounts of soluble fiber, so it’s regarded as a low FODMAP food.

Foods generally thought to trigger or worsen symptoms in people with IBS include (3, 5):

• High fat foods: fried foods, fatty meats, full fat dairy, eggs, avocados, nuts, and seeds
• Caffeine-rich items: coffee, tea, chocolate, and energy drinks
• Spicy foods: hot peppers, garlic, hot sauce, salsa, and meals made with large quantities of spices
• Dairy: milk, cheese, yogurt, and ice cream
• FODMAP-rich foods: legumes, honey, sweeteners, dairy, wheat, rye, barley, and some fruits and vegetables

Keep in mind that people with IBS may react to these foods differently. While a certain food may be a sure trigger for one person, the same food may be of little concern to another.

Keeping a food journal may help you identify which foods trigger your IBS symptoms so that you can replace them with suitable alternatives. This is best done with the guidance of a registered dietitian (RD) to ensure that your diet continues to meet your nutritional needs.

SUMMARY

Spicy foods, as well as those rich in fat, caffeine, dairy, or FODMAPs, are the most likely triggers of IBS symptoms. Keeping a food journal may help you track which ones affect you most.

You may find that lettuce happens to trigger your IBS symptoms despite its low fiber content.

If so, you can try replacing it with other low FODMAP vegetables and leafy greens.

For instance, spinach, arugula, kale, and Swiss chard make great substitutes for lettuce when making a salad. You can top this salad with low FODMAP veggies like bok choy, bean sprouts, red bell peppers, carrots, chives, cucumber, eggplant, green beans, or tomatoes.

SUMMARY

If you suspect lettuce may trigger your IBS symptoms, try replacing it with other low FODMAP veggies like kale, bean sprouts, or cucumber.

Lettuce is a low FODMAP vegetable that’s also very low in fiber.

As such, it’s unlikely to trigger or worsen your IBS symptoms. In fact, it may even ease your symptoms due to its low FODMAP content.

That said, trigger foods are highly individual and may affect certain people differently. If you suspect that lettuce causes your symptoms, simply replace it with other low FODMAP greens like spinach, arugula, kale, or Swiss chard.