Is Eating Raw Kale Really Cause for Concern? Dietitians Say No, at Least Not Most of the Time

But as often as we may sing the praises of this popular leafy green, going down a rabbit hole regarding the benefits (or not) of eating kale in its raw form might leave you second-guessing whether it's actually any good for you. (Especially if Dr. Google has a say in it. Big sigh.) So, let's set the record straight: Can you eat kale raw, and, more importantly, should you? To put it plainly, it undoubtedly gets the green (pun intended) light for most folks. But, for others, there may be a few instances where you're better off swapping kale for another one of your favorite healthy leafy greens. Ahead, we hear from two registered dietitians about the pros and cons of eating raw kale and how it may impact you.

Can you eat kale raw every day?

Yes, definitely. But should everyone? Perhaps not.

As a food that's known for its impressive nutritional profile, there's really no wrong way to use it. Kale has made its way into salads, smoothies, green juices, tacos, pasta dishes, and more. You can even find it in the chip aisle. And while eating as much of the leafy green as possible (no matter the type of kale) isn't a problem for most people, a handful may need to watch their intake when eating raw kale. While kale itself is an all-star, one thing that gives it its bright and shiny gold star in the health world is also something that can lead to health issues in certain individuals. Let's dig a little deeper.

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3 potential side effects of eating raw kale

1. It may impact your thyroid

For starters, raw kale is made up of a compound that can affect ones metabolism in both good and potentially "bad" ways. "Kale gets its super healthy reputation in part because of compounds called glucosinolates," says registered dietitian Brierley Horton, MS, RD. (Found in all cruciferous vegetables, glucosinolates are the subject of intense research centered on cancer prevention.)

However, Horton notes that it’s this exact compound that can also potentially pose a problem for some folks and their metabolisms. How? Glucosinolates can impact your thyroid, which is responsible for keeping your metabolism under control and in check. The good news? These compounds are only present in raw kale. In fact, an easy way to lessen the glucosinolate load is simply boiling kale since the compound is considered water-soluble.

But, even then, to really hinder or impact your thyroid you would have to eat a lot of kale. One endocrinologist told me that it would have to be bowls and bowls to really be an issue. That is, unless you have hypothyroidism, an underactive thyroid gland.

2. It may impact your kidneys

Along with creating some thyroid concerns when consumed in large quantities, Beth Basham, MS, RD, LD, says eating raw kale may affect another subset of the population: those susceptible to kidney stones. "Another population that might be weary of regular raw kale consumption would be those with kidney stones who have been told to follow an oxalate-restricted diet," Basham says. "Oxalates are a compound commonly found in foods—included, but not limited to—kale, spinach, beets, and nut butters. Excess consumption of oxalate-containing foods can be problematic for those who are susceptible and may lead to pain and future kidney stone development," she says.

3. It may be more difficult to digest

Kale is an extremely fibrous vegetable packed with boatloads of fiber per serving. Although this is typically good news for gut health, having a little too much fiber at once can lead to digestive discomfort. As such, consuming raw kale in moderation can be the best solution if it's tough on your digestion.

Best ways to consume kale

1. Cook it

Worried about raw kale's potential impact on your thyroid health? No problem, just cook it. "Glucosinolates are greatly diminished by cooking, so it’s good advice to boil, roast, or stew your kale before eating. This is the same for any other cruciferous veggie like broccoli, Brussels sprouts, cabbage, cauliflower, collards, kohlrabi, and bok choy," Basham says. Keep in mind that steaming raw kale won't be as effective in lowering the glucosinolate content as the other aforementioned cooking techniques.

On the flip side, if oxalates and kidney health are top of mind, cooking raw kale, unfortunately, won't help much. "Oxalates, on the other hand, aren't shown to be affected by cooking, so if you're on an oxalate-restricted diet, you may still need to moderate your intake," Basham says. In this case, consuming kale in moderation is key.

2. Mix things up

Instead of always enjoying kale the same way all the time, Horton says it's a good idea to mix things up every once in a while. "Don’t always eat it raw or juiced. Roast it, sauté it, or bake it," she says. Basham also recommends pairing kale with healthy fats to give it an extra nutrient boost. "Eating your veggies with fat increases the availability of fat-soluble vitamins D, E, A, and K from the food source—a benefit you don't want to miss out on," she explains. "Lightly sautéing or drizzling your crucifers with coconut oil, ghee, butter, or extra-virgin olive oil are all nourishing ways to accomplish this task," Basham says.

3. Make more than just green smoothies

Giving up your beloved smoothies—or at least cutting down on them!—might seem impossible. But doing so could add more versatility to your daily kale-enjoying routine. "Consider ditching the daily green smoothies and eating a normal, whole foods meal. Will a green smoothie kill you? No. In fact, they're enjoyable from time to time. But drinking more than one daily probably provides little benefit and may pose some risks," Basham says. "There's no current recommendation on the number of green smoothies you can have, but if you can't live without them, limit consumption to three or four times per week if you include raw kale," she says.

4. Massage it

Indeed, massaging kale isn't just a chef-inspired concept or tedious cooking step. It can also help make kale a bit more digestible and easier on the gut. This is because rubbing the leaves can help tenderize them, transforming them from a tough, fibrous plant to a more digestible, easier-to-chew star ingredient in your favorite kale salad recipe.

Cooked vs. raw kale: What's better?

But from a nutritional standpoint, keep in mind that cooked vs. raw kale differ ever so slightly. On the one hand, cooked kale may have fewer antioxidants, vitamins, and minerals, but can be beneficial for those with thyroid concerns. While raw kale may be harder to digest, but higher in nutrients. Ultimately, either way to include kale in your daily routine that meshes best with your lifestyle and health is the best way to go.

Bottom line

Don't worry, you probably don't need to rethink those gigantic raw kale salads for lunch anytime in the near future. "The hype about raw kale is mostly just that. The majority of folks won’t be impacted," Horton says. "And if you have hypothyroidism, raw kale—and other crucifers—aren’t off limits. Your approach then should be consistency. If you’re consistent about how much raw kale you eat, you and your doctor can appropriately titrate your synthroid dosage," she says.

That said, whether you're someone who's affected by the raw greens or not it's best to chat with a medical professional to come up with a game plan appropriate for your health concerns and goals.

How to make a tasty kale salad with a honey lemon vinaigrette: