Kale
Summary
What it is
Common uses
Public Perception
Anxiety level
Cultural claims
Source sentiment
History
Timeline
Origin
Science
Key findings
Studies
Safety status
Nuance
Alternatives
Swaps
Avoidance tips
References

Fact-checked by Lucent 3 months ago

Kale

ingredientCommodities

Total Sources: 49

Verified Claims: 35

Scientific Sources: 21

Summary

Kale is a leafy green vegetable belonging to the _Brassica oleracea_ species, known for its nutritional value and versatility as both a food source and ornamental plant [25], [23]. It is used in various dishes and has gained popularity as a "superfood" [16], [26].

What it is

Kale is a cultivar of cabbage grown for its edible leaves, which can be bumpy, curly, or flat, and range in color from purple to green [25].

Common uses

  • Ingredient in salads, soups, and smoothies [26]

  • Side dish [32]

  • Ornamental plant [25]

Public Perception

Anxiety level

Moderate. While kale is generally considered safe and healthy, concerns about pesticide contamination, 'forever chemicals', thyroid issues, and digestive problems may cause anxiety for some consumers [22], [24], [44].

Cultural claims

  • In Scotland, 'kail' was a generic term for dinner [27]

  • During World War II in England, citizens were encouraged to grow kale in victory gardens [26]

  • In Japan, kale is dried and ground into a powder for green drinks [26]

Source sentiment

Kale is generally viewed positively as a healthy and versatile vegetable, though some sources express concern about potential risks from excessive consumption or contamination [26], [22], [30].

History

Timeline

-400

Curly-leaved and flat-leaved varieties of cabbage existed in Greece; Romans referred to Sabellian kale as ancestors of modern kales [25].

1300

Hard-heading cabbage recorded in Western Europe [25].

1400

Distinction made in England between hard-heading cabbage and loose-leaf kale [25].

1800

Russian traders introduced Russian kale into Canada and the United States [25].

2007

Food writer Melissa Clark sparked the American raw kale salad trend [26].

2012

_Bon Appétit_ named 2012 the year of kale [27].

2013

The first annual National Kale Day was celebrated on October 2 [27].

Origin

Kale was cultivated for food in the eastern Mediterranean and Anatolia [25].

First appeared: -2000

Science

Key findings

  • Kale can attenuate inflammation and modulate gut microbial composition in mice with diet-induced obesity [7], [8].

  • Kale contains chemicals thought to help prevent cancer and might also have antioxidant activity [23].

  • Age, income, and educational status were significant contributors for predicting better knowledge scores about kale and its health benefits [16].

Studies

Beneficial Effects of a Freeze-Dried Kale Bar on Type 2 Diabetes Patients

A clinical trial studied the effects of freeze-dried kale bars on patients with type 2 diabetes [5].

Kale Attenuates Inflammation and Modulates Gut Microbial Composition and Function in C57BL/6J Mice with Diet-Induced Obesity

Kale supplementation lowered the Firmicutes: Bacteroidetes (F/B) ratio, increased both alpha and beta diversity, and reduced class Bacilli and Erysipelotrichi but had no effect on Clostridia in mice [8].

The Safety of Cruciferous Plants in Humans: A Systematic Review

A systematic review investigated the safety of cruciferous plants, including kale, in humans [13].

Safety status

Generally safe when consumed in moderation. Potential risks include pesticide exposure, 'forever chemicals' contamination, and thyroid issues with excessive raw consumption [13], [22], [24].

Nuance

While kale offers several health benefits, some studies have found pesticide residues and PFAS contamination in kale samples, raising concerns about potential health risks [22], [29].

Alternatives

Spinach

Spinach is a leafy green vegetable that is rich in iron, magnesium, potassium, calcium, folate, and vitamins A, C, E, and K [32].

Turnip Greens

Turnip greens are a good source of vitamin K, vitamin A, and folate [32].

Mustard Greens

Mustard greens are the slightly bitter leaves of the mustard plant and are a good source of vitamin K [32].

Swiss Chard

Swiss chard is a leafy green similar to spinach and is rich in potassium, magnesium, fiber, and vitamins A, C, and K [32].

Avoidance tips

  • Buy organic produce to minimize pesticide exposure [29], [30].

  • Wash kale thoroughly before consumption [30].

  • Cook kale to reduce goitrogenic compounds, especially for individuals with thyroid concerns [38], [44].

  • Consume kale in moderation as part of a balanced diet [38].

References

1.

https://www.who.int/publications/i/item/9789240060760