Detox
Kale
Cold-hardy, low-calorie, and ranked among the most nutrient-dense foods ever measured.
Bone Health
Detox
Vision
Serving
1 cup raw, chopped (67g)
Calories Per Serving
33
Key nutrients
Vitamin K, vitamin A, lutein, vitamin C
Nutrient density
1000
Why it’s worth eating
Kale is a leafy green that is high in vitamins A, C, K, and several minerals like manganese and copper. It’s known for its antioxidant and anti-inflammatory properties. Kale chips, salads, and smoothies are just a few ways to enjoy this superfood.
What you may notice
Markers worth tracking
How to eat it
Massage raw leaves with a little olive oil for a few minutes, or steam briefly, both break down tough cell walls and roughly triple absorption of vitamin K and carotenoids.
Pairs well with
Olive oil or any fat, vitamin K and carotenoids are fat-soluble Black pepper (piperine), boosts absorption of fat-soluble antioxidants
Storage
Refrigerate unwashed in a perforated bag for 5-7 days; freezes well after a quick blanch.
The numbers, per
393%
Vitamin K
37%
Vitamin A
89%
Vitamin C
8%
Calcium
5%
Iron
7%
Magnesium
7%
Potassium
0%
Vitamin B12
0%
Vitamin D
Fiber
2.4g
USDA-verified (FoodData Central)
Evidence
B
Genuine nutrient density. Specific clinical-endpoint evidence for kale as a food is thinner than its reputation implies; much rests on the shared crucifer glucosinolate mechanism.
Study dose vs. serving
Sulforaphane bioavailability is about 10% of dose without active myrosinase versus about 40% with it.
Shared crucifer glucosinolate/myrosinase evidence base (Fahey/Egner work, PLOS One 2015, PMC4394840).
Use caution if
You take warfarin or other blood thinners, keep intake consistent rather than spiking it You have hypothyroidism, raw kale’s goitrogens may reduce iodine uptake; cooking deactivates most of this
Details
Type
Superfood
Season
Autumn-winter, cold-hardy, sweeter after frost
Forms
Fresh, frozen, powder, chips
Price
Budget
Bioactive
Glucoraphanin and glucobrassicin (glucosinolates); also lutein and vitamin K
Heat stable
No - myrosinase is heat-inactivated. Chop raw and rest, or lightly steam rather than boil
Watch
High vitamin K: people on warfarin should keep intake consistent rather than avoid it.
Reliability
Research Reliability