How to Eat More Fibre-Rich Cruciferous Vegies with Fewer Gassy Side Effects

If you’ve ever overindulged in a tray of roasted broccoli or a pot of cabbage soup, you might be wondering how it’s possible for vegetables that are so good for you to make you feel so lousy. While there’s no denying they taste great going down, the bloating, farting and general gassiness that comes after isn’t quite so pleasant.

Let’s get one thing straight: cruciferous vegetables – like the broccoli and cabbage mentioned above, plus others like Brussels sprouts, kale and cauliflower – really are all they’re cracked up to be on the nutrient front. Offering an array of superstars like vitamin K, folate and fibre – not to mention compounds with antioxidant and anti-inflammatory properties – they can provide a range of benefits, from improving gut health to potentially preventing cancer. So they’re definitely ones you want to put on your plate.

But it’s also equally true that some of the very characteristics that make these vegies so darn nutritious are also responsible for certain unpleasant side effects – namely, gastrointestinal issues like bowel distension and excessive (sometimes stinky) flatulence.

Take their fibre. The type found in cruciferous vegies is what’s known as fermentable carbohydrate, which is broken down by gut microbes in your large intestine through a fermentation process that produces all that uncomfortable gas, says Jessie Hoffman, a dietitian and board-certified specialist in digestive health. As for that odoriferous smell? You can blame the sulphur-containing compounds in these vegetables – the same ones that may have anticarcinogenic properties, she says.

That doesn’t mean you need to resign yourself to a life of GI discomfort to reap the benefits of cruciferous vegetables. Dietitians say there are things you can do to limit the negatives, so you can start truly enjoying all the good that cruciferous vegies have to offer.

Start with smaller quantities and increase (or don’t!) from there.

Whenever you increase the amount of fibre in your diet, it’s a good idea to start slowly to give your digestive system and microbiome time to adjust, says Jessie. That’s especially true in the case of cruciferous vegetables, whose fermentable fibres are among the more gas-inducing forms of the nutrient.

The larger the portion of fermentable carbohydrates you’re consuming, the more fuel you’re giving your gut microbes to create gas, so reducing your intake is generally sufficient to lessen that effect, says Jessie. She recommends starting with a half-cup serving of cruciferous vegetables in a meal and going up from there, noting that those with sensitive guts or gastrointestinal disorders like irritable bowel syndrome (IBS) may be better off beginning with an even lower serving size, like a quarter of a cup.

“There’s really not a one-size-fits-all recommendation, though,” she says. “Some people can eat much larger portions without any issues, while others can experience symptoms with small amounts.” Once your gut has had some time to get used to those fermentable fibres, you may be able to inch up your portion size without causing GI distress.

Just remember: a bit of gas is to be expected when you start eating these kinds of vegies, but if what you’re experiencing feels abnormal or very painful, something else might be at play, like untreated small intestinal bacterial overgrowth (SIBO) or cruciferous vegetable allergies, says Lindsay Malone, a dietitian and nutrition instructor.

Try eating them a little slower.

Serving size isn’t the only factor that can affect how gassy you get. How quickly you eat cruciferous vegetables matters too, says Lindsay. It increases the amount of swallowed air, she explains, which contributes to bloating, belching and passing gas.

Slowly savouring your food is also a good way to better perceive fullness cues. That way, you can stop before overdoing it and straining your digestive system. She recommends this approach for mealtimes in general, but especially in the case of cruciferous vegetables, where the side effects of going overboard are so infamously unpleasant.

Experiment with different kinds of cruciferous vegetables.

Cruciferous vegetables contain fermentable fibres in varying quantities, so some may be easier to digest whereas others could create issues, says Jessie. For example, cauliflower and Brussels sprouts may have greater amounts of those GI-problem-causing carbohydrates, whereas bok choy, kale and broccoli florets may have less and are generally better tolerated, Lindsay says.

Just keep in mind that everyone is different, and each person’s tolerance to these foods will vary, says Jessie. That’s why she recommends a bit of trial and error to see how you react to different cruciferous vegetables. At first, you’ll want to avoid combining them so you can get a clear picture of the way they affect your digestive system. From there, it’s only a matter of time before you know what works for you and your gut.

Consider using an alternative cooking method.

Any type of cooking is generally going to make cruciferous vegetables easier to tolerate than eating them raw, says Jessie. “It softens some of these tougher plant structures and reduces some of the work your body has to do during chewing and digestion,” she explains.

Not all cruciferous cooking methods are created equal, though. Boiling, for instance, is advantageous for reducing gas and bloat because of how it softens the vegetables, but the process also leaches certain water-soluble vitamins like C and B out of the vegetable, Jessie explains.

Instead, she recommends steaming or roasting, which also soften the fibres but do a better job of retaining the water-soluble nutrients – and they generally make your food more flavourful, too. If you’d rather not turn on the stove or oven but still want the benefits of a cruciferous vegetable, blending something like kale into a smoothie is also an effective way to break down the fibres for easier digestion.

Be aware of the total amount of fermentable fibers you’re eating throughout the day.

Cruciferous vegetables aren’t the only type of produce that contains fermentable fibres – they can also be found in vegetables and fruits like onions and mango. And you can experience a cumulative effect from multiple food sources throughout your daily meals, says Lindsay.

While it might be easy to blame your stomach cramps and gas on a bowl of broccoli and cheddar soup, those symptoms could actually have more to do with what you ate earlier. “A bag full of dried mango in the afternoon can impact how you feel after your dinner with cauliflower rice,” Lindsay explains.

So, if you continue to struggle with excess bloating and flatulence despite employing all the tricks here, it might be time to take a step back and look at what else you’ve been eating. Lindsay says approaches like the low-FODMAP diet and the low-fermentation diet, as well as working with a professional like an Accredited Practising Dietitian (APD), can help you target what’s really causing your problem.