Cruciferous vegetables

Vegetables of the family Brassicaceae (also called Cruciferae) are called cruciferous vegetables. The vegetables are widely cultivated, with many genera, species, and cultivars being raised for food production such as cauliflower, cabbage, cress, bok choy, broccoli and similar green leaf vegetables. The family takes its alternate name (Cruciferae, New Latin for "cross-bearing") from the shape of their flowers, whose four petals resemble a cross.

Ten of the most common vegetables eaten by people are in a single species (B. oleracea), and are not distinguished from one another taxonomically, but only by the horticultural category of cultivar groups. Numerous other genera and species in the family are also edible. Cruciferous vegetables are one of the dominant food crops worldwide. Widely considered to be healthy foods, they are high in vitamin C and soluble fibre and contain multiple nutrients and phytochemicals with potential anti-cancer properties: diindolylmethane, sulforaphane and selenium. Both diindolylmethane, sulforaphane, and many other sharp-tasting substances in these vegetables are produced from substances called glucosinolates.

Researchers at the University of California, Berkeley, have discovered that 3,3'-diindolylmethane in Brassica vegetables is a strong androgen receptor antagonist in human prostate cancer cells.[1]

Cruciferous vegetables can potentially be goitrogenic (inducing goiter formation). They contain enzymes that interfere with the formation of thyroid hormone.[2][3] Cooking for 30 minutes significantly reduces the amount of goitrogens and nitriles. At high intake of crucifers, the goitrogens inhibit the incorporation of iodine into thyroid hormone and also the transfer of iodine into milk by the mammary gland.[4]

Cruciferous vegetables have recently been implicated in some pharmacological drug interactions. These vegetables are powerful inducers of the microsomal cytochrome P450 enzyme CYP1A2, which is responsible for the metabolism of many pharmacological agents.[5] By causing induction of the enzyme, it may incidentally increase the rate of phase I transformations (see pharmacokinetics) of pharmocological agents that are normally metabolized by this enzyme, expediting the process of drug metabolism. This, in turn, could produce drug plasma concentration that is less than the desired therapeutic range.

It has been found that cruciferous vegetables are less likely to be eaten by people who can taste PTC,[6] due to the existence of compounds related to PTC in such vegetables.

List of cruciferous vegetables

Extensive selective breeding has produced a large variety of cultivars, especially within the genus Brassica. One description of genetic factors involved in the breeding of Brassica species is the Triangle of U.

The taxonomy of common cruciferous vegetables
common name genus specific epithet Cultivar Group
horseradish Armoracia rusticana
land cress Barbarea verna
ethiopian mustard Brassica carinata
kale Brassica oleracea Acephala Group
collard greens Brassica oleracea Acephala Group
Chinese broccoli (kai-lan) Brassica oleracea Alboglabra Group
cabbage Brassica oleracea Capitata Group
brussels sprout Brassica oleracea Gemmifera Group
kohlrabi Brassica oleracea Gongylodes Group
broccoli Brassica oleracea Italica Group
broccoflower Brassica oleracea Italica Group × Botrytis Group
broccoli romanesco Brassica oleracea Botrytis Group / Italica Group
cauliflower Brassica oleracea Botrytis Group
wild broccoli Brassica oleracea Oleracea Group
bok choy Brassica rapa chinensis
komatsuna Brassica rapa pervidis or komatsuna
mizuna Brassica rapa nipposinica
Rapini (broccoli rabe) Brassica rapa parachinensis
flowering cabbage Brassica rapa parachinensis
chinese cabbage, napa cabbage Brassica rapa pekinensis
turnip root; greens Brassica rapa rapifera
rutabaga Brassica napus napobrassica
siberian kale Brassica napus pabularia
canola/rapeseed Brassica rapa/napus oleifera
wrapped heart mustard cabbage Brassica juncea rugosa
mustard seeds, brown; greens Brassica juncea
mustard seeds, white Brassica (or Sinapis) hirta
mustard seeds, black Brassica nigra
tatsoi Brassica rosularis
arugula (rocket) Eruca vesicaria
garden cress Lepidium sativum
watercress Nasturtium officinale
radish Raphanus sativus
daikon Raphanus sativus longipinnatus
wasabi Wasabia japonica

Notes

  1. ^ Plant-derived 3,3'-Diindolylmethane Is a Strong Androgen Antagonist in Human Prostate Cancer Cells* Hien T. Le , Charlene M. Schaldach , Gary L. Firestone ¶ and Leonard F. Bjeldanes. J. Biol. Chem., Vol. 278, Issue 23, 21136-21145, June 6, 2003. http://www.jbc.org/cgi/content/abstract/278/23/21136
  2. ^ What are Goitrogens and How Do they Affect the Thyroid?, Mary Shomon, author of Your Guide to Thyroid Disease
  3. ^ Thyroid Deficiency Strikes One in Six, John McDougall, McDougall Newsletter, Volume 4, Number 12, December, 2005.
  4. ^ "Bearers of the Cross: Crucifers in the Context of Traditional Diets and Modern Science". http://www.westonaprice.org/basicnutrition/crucifers.html#goitrogens. 
  5. ^ Brassica vegetables increase and apiaceous vegetables decrease cytochrome P450 1A2 activity in humans: changes in caffeine metabolite ratios in response to controlled vegetable diets, Johanna W. Lampe, Irena B. King, Sue Li, Margaret T. Grate, Karen V. Barale, Chu Chen1, Ziding Feng and John D. Potter, Cancer Prevention Research Program and Program in Epidemiology, Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, Seattle, WA 98109-1024, USA http://carcin.oxfordjournals.org/cgi/content/abstract/21/6/1157
  6. ^ "Natural Selection at Work in Genetic Variation to Taste". http://www.scienceblog.com/cms/node/3114. Retrieved 2009-07-29. 

References