Which is more nutritious kale or spinach?

Introduction

Kale and spinach are two of the most nutritious leafy green vegetables around. Both are packed with vitamins, minerals, fiber and antioxidants. However, there are some key differences between these two superfoods when it comes to their nutritional profiles. This article will compare kale vs spinach to determine which comes out on top in terms of nutritional value.

Nutrient profiles

Below is a comparison of the main nutrients in kale and spinach (per 100 grams or 3.5 oz).

Nutrient	Kale	Spinach
Calories	49	23
Protein	4.3g	2.9g
Carbs	8.8g	3.6g
Fiber	3.6g	2.2g
Vitamin A	1094% DV	188% DV
Vitamin C	200% DV	28% DV
Vitamin K	1124% DV	482% DV
Vitamin B6	22% DV	11% DV
Manganese	26% DV	25% DV
Calcium	18% DV	10% DV
Iron	15% DV	20% DV
Magnesium	11% DV	22% DV
Potassium	9% DV	12% DV

As you can see from the table, both kale and spinach contain a wide array of important vitamins and minerals. However, kale comes out higher in certain nutrients like vitamins A, C and K. Meanwhile, spinach contains more magnesium and iron.

Vitamin and mineral differences

Let’s take a more in-depth look at some of the key nutritional differences between kale and spinach.

Vitamin A

One of the biggest differences is vitamin A content. Kale provides a whopping 1094% of the daily value for vitamin A per 100 grams. This dwarfs spinach’s 188% DV.

Vitamin A is important for eye health, immune function and cell growth. The high amount in kale comes from beta-carotene, an antioxidant form of vitamin A.

Vitamin C

Kale beats out spinach when it comes to vitamin C as well, with about 200% DV versus 28% DV per 100 grams.

Vitamin C is a powerful antioxidant that promotes skin health, iron absorption and immune function. As an antioxidant, it helps neutralize free radicals that can damage cells.

Vitamin K

Spinach and kale are both extremely high in vitamin K, which plays a key role in blood clotting. However, kale contains over twice as much as spinach, with 1124% DV compared to 482% DV per 100 grams.

Vitamin K may also help promote bone health and reduce risk of heart disease. The extremely high amounts in kale and spinach make them two of the best plant-based sources of this nutrient.

Iron

Although kale contains a decent amount of iron at 15% DV, spinach provides even more at 20% DV per 100 grams.

Iron is essential for creating hemoglobin, allowing red blood cells to carry oxygen throughout your body. Iron deficiency can cause anemia and fatigue.

Magnesium

Spinach has almost twice as much magnesium as kale, with 22% DV versus 11% DV per 100 grams.

Magnesium plays a role in over 300 bodily processes, including muscle and nerve function, blood glucose control, and blood pressure regulation. Most people don’t get enough of this important mineral.

Potassium

Finally, spinach contains a bit more potassium than kale – 12% DV versus 9% DV per 100 grams.

Potassium helps reduce blood pressure by balancing out negative effects of sodium. It also supports bone health and muscle function.

Phytochemical differences

In addition to vitamins and minerals, kale and spinach also contain beneficial plant compounds called phytochemicals or phytonutrients.

These phytochemicals are thought to have antioxidant, anti-inflammatory, and anti-cancer effects in the body. Let’s look at a few of the key phytochemical differences between kale and spinach.

Carotenoids

Kale contains a type of carotenoid antioxidant called lutein. In fact, one serving of kale provides over 10mg of lutein.

Lutein helps promote eye health and may help prevent macular degeneration, a leading cause of blindness.

Spinach also provides lutein, but about 9 times less than kale. So kale is the winner when it comes to lutein content.

Flavonoids

Spinach contains higher amounts of certain flavonoids, a type of antioxidant phytochemical, compared to kale.

One particular flavonoid called patuletin is found in spinach but not kale. Patuletin has been studied for potential anti-cancer effects.

Overall, the flavonoid content may be higher in spinach – giving it an edge in this category.

Glucosinolates

On the other hand, kale contains more glucosinolates than spinach.

Glucosinolates are phytochemicals thought to have anti-cancer properties. Some research also indicates they may support detoxification in the body.

Because kale provides more glucosinolates, it wins when it comes to this beneficial phytochemical.

Health benefits

Both kale and spinach have been associated with a variety of health benefits. However, there are some differences when it comes to the research behind each veggie’s effects.

Cancer prevention

Several studies have found connections between higher leafy green intake and reduced risk of certain cancers, including breast and prostate cancer. The phytochemicals in greens are thought to have protective effects.

Kale’s high glucosinolate content may give it an edge when it comes to cancer prevention. But more research is needed comparing kale versus spinach directly.

Heart health

Leafy greens in general promote heart health, thanks to their vitamins, minerals, fiber and antioxidants.

Both spinach and kale contain lutein. This carotenoid antioxidant has been linked with lower risk of atherosclerosis, heart attacks and strokes.

Overall the two greens likely support heart health similarly, with few studies comparing them directly.

Blood pressure

Studies show nitrate-rich greens like spinach may promote lower blood pressure levels. Nitrates help widen and relax blood vessels.

Kale contains less nitrates than spinach. But both veggies provide potassium, which helps balance sodium to support healthy blood pressure.

So spinach may have a slight upper hand when it comes to reducing high blood pressure. But kale still offers benefits.

Digestion

With 3.6 grams of fiber per 100 grams, kale provides more fiber than spinach at 2.2 grams.

Fiber promotes healthy digestion and bowel regularity. It also feeds the healthy bacteria in your gut microbiome.

The extra fiber in kale could give it an advantage for gut health and digestion. But both are great high fiber food sources.

Vision health

Lutein and zeaxanthin are two carotenoids found in greens that support eye health by protecting the retina and reducing risk of disorders.

Kale provides 10 times more lutein than spinach, along with decent zeaxanthin amounts. This may give kale an advantage for protecting vision.

Skin and hair

Vitamin A, C and K support skin and hair health. Vitamin C helps make collagen and defend against damage. Vitamin A promotes healthy cell growth, while vitamin K activates proteins needed for skin renewal.

With higher amounts of vitamins A and C, kale may be better for your skin and hair. But spinach’s vitamin K still supports skin health.

Downsides

Kale and spinach are both very healthy. However, there are a couple potential downsides to consider:

Oxalates

Kale and spinach both contain oxalates, which are antinutrients that can bind to minerals like calcium and iron, reducing their absorption.

People prone to kidney stones may want to watch oxalate intake from greens like kale and spinach. But for most people without issues, this is likely not a major concern.

Pesticide exposure

The Environmental Working Group lists both kale and spinach on its “Dirty Dozen” list of produce highest in pesticide residues. This means conventional (non-organic) varieties may have higher pesticide contamination.

Going organic can help reduce exposure to potentially harmful pesticides found on conventionally grown produce.

And the winner is…

Based on the nutritional profiles, kale and spinach both bring some great benefits to the table. Here is a quick recap:

Kale benefits

• Higher in vitamins A, C and K
• More fiber
• Higher in lutein for eye health
• More glucosinolates linked with cancer prevention
• May be better for skin and digestion

Spinach benefits

• Higher in vitamins E and B6
• More magnesium and iron
• Higher in flavonoids like patuletin
• More nitrates for heart health and blood pressure

When it comes down to it, kale edges out spinach as the nutritional winner due to its stellar nutrient and phytochemical profile. But really you can’t go wrong with adding either of these powerhouse greens into your diet.

Incorporating kale and spinach

Here are some tips for reaping the benefits of kale and spinach:

• Add raw kale or spinach to smoothies and green juices
• Saute with olive oil, garlic, lemon juice, and spices for a nutritious side dish
• Add handfuls of greens to soups, stews, casseroles and pasta dishes
• Top pizza with greens after baking
• Toss into salads or use as salad base
• Add to omelets, frittatas, sandwiches and wraps

When cooking greens, avoid overcooking which can diminish nutrient content. Blanching or steaming briefly helps retain nutrients while still softening greens to enhance palatability.

To boost absorption of fat soluble vitamins A, K, E, serve greens alongside a source of healthy fat like olive oil, nuts, or avocado.

So which green will you add to your next meal? Both kale and spinach are leafy green superstars loaded with nutritional benefits, so be sure to eat up and reap the rewards!

Conclusion

Kale and spinach are both nutritional powerhouses filled with vitamins, minerals, and phytochemicals that promote health and help reduce risk of chronic diseases. However, kale comes out on top as the most nutritious overall based on its stellar content of vitamins A, C, and K as well as glucosinolates linked with cancer prevention. Spinach also brings great nutrition to the table, especially with its nitrates for heart health, magnesium, and flavonoids. To get the most benefits, add both greens into a healthy, balanced diet. Just remember to go for organic whenever possible to reduce pesticide exposure from these Dirty Dozen produce picks. With its stellar nutritional profile, kale takes the trophy for most nutritious green – but any way you slice it, you can’t go wrong adding more fresh, leafy greens like kale and spinach into your diet.