Last verified: 46 days ago
Kale
Also known as: Brassica oleracea var. sabellica, curly kale, leaf cabbage, borecole
Evidence under review. — Not yet rated
Nutrient-dense leafy green with early evidence for blood sugar and inflammation support. Research is still limited.
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What it does
Kale is a cruciferous leafy green vegetable packed with carotenoids, anthocyanins, and other plant compounds. Early clinical trials suggest that high daily intake of freeze-dried kale may help...
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Evidence quality
Evidence base hasn't been formally rated yet. See research below.
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Clinical dose
No established dose; studies used 79 g/day (raw/steamed) to ~341 g/day (freeze-dried equivalent)
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Found in
Newchapter, Nature's Answer Licorice Root Extract, Amazing Grass Organic Supergreens Powder and 17 more
What the Science Says
Kale is a cruciferous leafy green vegetable packed with carotenoids, anthocyanins, and other plant compounds. Early clinical trials suggest that high daily intake of freeze-dried kale may help reduce HbA1c and insulin resistance in people with type 2 diabetes over 12 weeks, and a kale extract showed anti-inflammatory effects comparable to ibuprofen after dental surgery. A separate small study found that daily carotenoid-rich kale extract improved skin collagen markers over 5–10 months.
What It Doesn't Do
Not a proven diabetes treatment — the blood sugar study was tiny (30 people) and needs replication. Won't balance your hormones: one study found no change in estrogen metabolite ratios from cruciferous vegetable intake. Not a substitute for prescribed medication. No solid evidence it detoxifies your body or prevents cancer based on the provided studies.
Evidence-Based Benefits
Kale is rich in vitamins A, C, and K, as well as antioxidants and fiber, which can contribute to overall health. Research indicates that regular consumption may support heart health, reduce inflammation, and improve digestive health.
Strong EvidenceEffective at: No established dose
Source: auto-research
Absorption & Bioavailability
Unknown from provided studies; carotenoid absorption likely enhanced by fat co-consumption (general nutrition principle), but no pharmacokinetic data provided in the reviewed papers
Red Flags to Watch For
- Kale can bioaccumulate thallium, a toxic heavy metal — a published case report linked commercial kale chips to dangerously elevated urine thallium levels in a mother and three children
- Kale chips and concentrated supplements may contain higher levels of contaminants (thallium, pesticide residues like etofenprox) than fresh kale due to dehydration concentrating both nutrients and toxins
- Pesticide residue risk is real — a 2025 study evaluated etofenprox dissipation in kale, highlighting that residues can persist on the leaf surface
- Most human clinical trials are very small (20–30 participants) and short-term; do not assume supplement-level doses replicate whole-food benefits
- People on blood thinners (warfarin) should be cautious with large kale doses due to high vitamin K content — not covered in provided studies but a known interaction
Products Containing Kale
See how Kale is used in these analyzed products:
Newchapter
Supplement
Nature's Answer Licorice Root Extract
Supplement
Amazing Grass Organic Supergreens Powder
Supplement
Country Farms Collagen + Greens Powder
Supplement
Sunfood Organic Green Blend
Supplement
Live it Up Super Greens
Supplement
Paleovalley Organic Supergreens
Supplement
310 Greens - Mixed Berry
Supplement
HealthForce SuperFoods Vitamineral Green
Supplement
Greens by Inspired Nutraceuticals
Supplement
KOS Organic Superfood Greens - Apple Flavor
Supplement
Lemme Greens Gummies
Supplement
Peak Performance Organic Greens Superfood Powder
Supplement
Smartvita Men's Total Synergy Multivitamins
Supplement
310 Chocolate Icing Shake
Supplement
Supergreen Tonik
Supplement
Sunfood Supergreens & Protein
Supplement
WonderGreens Veggie Gummies
Supplement
Kiala Super Greens Gummies
Supplement
Transformation Super Greens (SPR BODY)
Supplement
Research Sources
- PubMed
- NIH DSLD
This information is for educational purposes only and is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Last updated: 2026-04-06