Spinach and kale are often pitted against each other in a friendly rivalry in the realm of healthy eating.
But is there a winner?
"Spinach and kale are both healthy and incredibly nutrient-dense dark leafy green vegetables," said Stephanie McKercher, a registered dietitian and plant-based recipe developer in Denver, Colorado, at GratefulGrazer.com.
"While similar, there are a couple of key differences in the nutrient compositions of each," McKercher added.
Spinach and kale are pictured in file images (Credit: Hauke-Christian Dittrich/picture alliance and Natasha Breen/REDA&CO/Universal Images Group via Getty Images)
Natalie Gillett, a New Jersey-based registered dietitian and owner of NatalieGillettNutrition.com, echoed that sentiment, noting that the two leafy greens have distinct healthy benefits, which "merit giving both of these power foods a regular place in your fridge."
Expanding on that further, Romane Guerot, a registered dietitian, sports nutritionist and lifestyle coach based in Paris at Foodvisor.io/en, said kale is a good source of fiber, vitamins A, C, and K, as well as calcium.
She added about its "rival," "Spinach is a good source of iron, potassium, vitamins A, C, and K, as well as folate and magnesium."
Read on to learn the nutrition profiles of kale and spinach — and find out if one reigns supreme.
The nutrition specifics of kale
Kale is a fiber powerhouse. It's brimming with vitamin C, too.
"Kale is higher in fiber and contains more vitamin C than spinach," said McKercher.
"Vitamin C works as an antioxidant. It aids the immune system and helps with iron absorption."
In terms of other notable vitamins, kale and spinach are both rich sources of vitamin K, said McKercher, which is important for bone health and blood clotting.
Gillett also singled out kale for its vitamin A content, "which supports vision, immune system and tissue health," as well as the mineral potassium, involved in muscle contractions and in helping to maintain healthy blood pressure.
Gillett is also a fan of just how chock-full of fiber kale is.
"One cup of cooked kale provides almost five grams, which is nearly 20% of the daily recommendation of fiber," she said.
As for other factors that set kale apart from spinach, Gillett shared that kale is a part of the cruciferous vegetable family.
"Cruciferous vegetables are notable for their high content of glucosinolates, which may be protective against cancer," she said, pointing to research that's been published on the National Cancer Institute's website.
Last but not least, kale is also a good source of antioxidants, "which can help protect the body from damage," said Guerot.
The nutrition specifics of spinach
Spinach is a much-praised veggie for good reason.
"Much like kale, spinach boasts impressive levels of vitamins K, C and calcium. While kale contains folate, spinach has it beat with more than double the amount for the same size serving," said Gillett.
She added that folate supports cell division and helps prevent birth defects during pregnancy.
"Compared to kale, spinach is notable for containing more iron, which is vital for blood cells, energy and growth," she said, noting that a 100-gram serving of cooked spinach has approximately 3.6 milligrams of iron, whereas the same amount of cooked kale contains around 1 milligram of iron.
"Spinach offers a nice amount of essential nutrients, including iron, vitamins A, K, and folate," said Guerot.
She said the iron found in spinach "is vital in preventing anemia."
Like kale, spinach is also high in fiber, "which aids in digestion and can help with weight management," said Gillett.
So is kale or spinach the healthier choice?
Like other nuanced nutrition debates, there’s no clear winner in the battle between kale and spinach.
"Both spinach and kale are exceptionally healthy and offer unique advantages," said Gillett. She said the choice between them largely depends on individual preferences and dietary needs.
Both of these leafy greens contain a variety of nutrients that are essential for good health, Guerot stressed.
"However, if you are looking for a food that is particularly high in fiber, vitamins K and C, kale is a better choice," she said.
"If you are looking for a food that is particularly high in folate and a source of iron, and vitamins A and E, then spinach is a better choice."
Ultimately, per Guerot, the best way to get the most nutrition from your diet is to eat a variety of fruits and vegetables, including both spinach and kale.
When it comes to fruits and veggies, the "eat-the-rainbow" adage is accurate.
"Eating a variety of vegetables gives your body the different nutrients it needs to thrive. Variety also makes meals more interesting and keeps boredom at bay," said McKercher.
"Because spinach and kale are nutritionally similar, you could also opt for whichever veggie you enjoy more," said Guerot.
Cooking with kale and spinach
In general, Gillett encouraged people to "experiment with both spinach and kale in your meals to enjoy their distinct flavors and health benefits."
Both spinach and kale can be eaten raw, cooked, or juiced.
"They can be added to salads, soups, smoothies and stir-fries," Guerot said.
"When choosing spinach or kale, look for leaves that are fresh and green. Avoid leaves that are yellow or brown," said Guerot.
When buying fresh spinach or kale, know that the leafy greens can be stored in the refrigerator for up to five days, she also said.
That said, buying frozen spinach and kale is also a nutrient-dense and budget-friendly option.
You can also keep frozen spinach or kale in the freezer for months at a time without worrying about any spoiling.
In terms of meal prep, McKercher suggested cooking either spinach or kale with a can of chickpeas and serving it with tahini sauce.
Check out her recipe on her Instagram page: @gratefulgrazer.