cruciferous (cross-bearing) vegetables

[Guest guest]

http://www.nih.gov/news/pr/sep2000/niehs-18.htm

 

NATIONAL INSTITUTES OF HEALTH

National Institute of Environmental Health Sciences

--

FOR IMMEDIATE RELEASE

Monday, September 18, 2000 Contacts:

Tom Hawkins 919-541-1402

John Peterson 919-541-7860

 

Broccoli, Cabbage, and a Variant Gene Nutrient in Cruciferous Vegetables

Protects Against Lung Cancer in Study of 18,244 Chinese;

Benefit Depends on Genetic Factor

 

A class of nutrients, isothiocyanates, found only in cruciferous vegetables

— broccoli, cauliflower, cabbage, watercress, bok choy, among others — was

protective against lung cancer in the study of a sample of 18,244 males,

45-64 years old, in Shanghai, China. The study also showed a unique

gene-diet interaction. Subjects genetically deficient in an enzyme (GSTM1)

that quickly eliminates isothiocyanates (ITC's) from the body got the most

benefit from cruciferous vegetables, presumably because ITC's stayed around

longer to confer their protective effect.

Among all subjects, those with detectable levels of isothiocyanates in the

urine had a 40% decrease risk of lung cancer. Among those lacking the

metabolism enzyme, a 64% decrease was noted.

 

Precursors of ITC's, a class of naturally occurring chemicals, are released

when cruciferous vegetables are chewed and the anticarcinogenic

isothiocyanates are formed.

 

The study appearing in the journal Lancet (Volume 355) was a collaboration

by scientists at the National Institute of Environmental Health Sciences,

Research Triangle Park, NC; University of Southern California, Los Angeles;

American Health Foundation, Valhalla, NY; and Shanghai Cancer Institute,

China. The study was funded through grants by NIEHS and the National Cancer

Institute, agencies of the National Institutes of Health.

 

Both blood and urine samples were collected from study participants. The

urine test for total ITC levels was developed by the researchers

specifically for epidemiological research. Stephanie London, NIEHS, a

co-lead-author, said, " We are aware of no prior data linking a biologic

marker of ITC intake to the risk of any cancer. " The authors noted that the

benefits of ITC's may vary between individuals and across populations based

on genetic variation in metabolism.

 

Subjects in the study were followed up through annual contacts with all

surviving cohort members and a twice yearly review of cancer reports from

the Shanghai Cancer registry and of death certificates.

 

" The main take home message is not that veggies are good, " London said. "

It is that we demonstrated a gene-diet interaction. The beneficial effect

of ITC's was predominantly seen among subjects who are predicted to

metabolize it more slowly based on their having deletion of a gene (GSTM1)

that rapidly eliminates these compounds from the body. The implication for

intervention studies is important. There is a lot of animal work on ITC's

which includes work to figure out which of them you would want to use in an

intervention and in what form. Our study adds significant human data to

this effort. "

 

 

 

http://www.walgreens.com/library/qod/qoda012501.jhtml

 

Q: What are cruciferous vegetables?

 

A: Cruciferous (krew-SIH-fer-uhs) is the scientific name for a group of

plants whose four petal flowers resemble a cross. These vegetables are a

part of the cabbage family and include arugula, bok choy, broccoli,

broccoli sprouts, Brussels sprouts, cabbage, cauliflower, Swiss chard,

collards, kale, kohlrabi, mustard greens, radishes, rutabaga, turnips,

turnip greens and watercress.

 

About 20 years ago, epidemiologic studies found that consumption of this

group of vegetables was associated with decreased risk for cancer. In the

early 1990s, two organic compounds in cruciferous vegetables containing

sulfur (dithiolthiones and isothiocyanates) were found to increase the

activity of enzymes involved in detoxifying some carcinogens. In addition,

a compound called indol-3-carbinol was found to affect estrogen metabolism

and is thought to be protective against estrogen-related cancers such as

cancer of the breast and uterus. Other beneficial substances found in

cruciferous vegetables include fiber and the antioxidants vitamin C and

beta carotene.

 

The chemical composition of this group of vegetables is complex, making it

difficult to isolate which compound or group of compounds provides benefit.

For now, the strongest evidence indicates that individuals who eat five

servings of fruits and vegetables — including cruciferous vegetables —

daily cut their risk for cancer by half when compared to those who consume

one serving or less. There is a wide choice of cruciferous vegetables. Eat

plenty.

 

— September 5, 2000 —

 

 

 

Cruciferous (Cabbage-family) Vegetables: " Best Buys " Guide

Fruits and vegetables have much flavor and nutrition. Eating a variety of

fruits and vegetables is recommended because they provide vitamins,

minerals, fiber and other natural substances, such as antioxidants and

phytochemicals, that are important for good health.

 

Eating cruciferous vegetables promotes good health and decreases risk for

colon and rectal cancers.

 

Try to eat 5 or more servings of fruits and vegetables each day, with at

least one serving per day of vitamin A-rich, vitamin C-rich, and fiber-rich

foods. In addition, eat several servings per week of cruciferous vegetables.

 

One way to stretch the value of your food dollar is to buy fresh fruits and

vegetables in season. The following information shows an alphabetical

listing of cruciferous vegetables. The " best time to buy " lets you know

when to buy those fruits and vegetables for the best quality at their

lowest cost.

 

Cruciferous Vegetable Best time to Buy

arugula

bok choy

broccoli February, March, April, July, August,

September, October, and November

Brussels sprouts October, November

cabbage March

cauliflower September. October, and November

collards

kale

kohlrabi

mustard greens

radishes

rutabaga

turnips

turnip greens

watercress

--

Mary L. Meck Higgins, Ph. D., RD, LD.

Extension Specialist, Nutrition Education

 

 

Pennsylvania State Unviersity

http://pubs.cas.psu.edu/FreePubs/uk043.html

 

Eat Five -- Lesson 5: Cruciferous Vegetables

This 14-page publication is the fifth of five learn-at-home lessons that

provide information on reducing the risk for certain types of cancers. The

lessons are tied to the National Cancer Institute's 5 a Day campaign, which

emphasizes eating five fruits and vegetables daily. This lesson focuses on

the benefits of eating cruciferous vegetables, and includes common

questions and answers, worksheets, fact sheets, tips, and recipes. (1995)

Code Number: UK043

Cost: Free

PDF: click here for uk043.pdf (220K)

http://pubs.cas.psu.edu/FreePubs/uk043.htm

 

 

Other great websites on cruciferous vegetables

http://qualitycounts.com/fpcruciferous.html

http://www.cnn.com/2001/HEALTH/conditions/03/13/cancer.defense.reut/index.html

http://www.intelihealth.com/IH/ihtIH/WSIHW000/333/7228/309103.html ---

from Harvard Medical School

http://www.lef.org/magazine/mag2000/july2000_i3c.html -- Prostate Cancer

and cruciferous vegetables

http://healthcentral.com/drdean/DeanFullTextTopics.cfm?ID=14116 - Cervical

Cancer and cruciferous vegetables

http://www.healthwellexchange.com/nutritionsciencenews/NSN_backs/Nov_98/q_and_a.\

cfm?

-- Cruciferae vs. Cancer

http://exchange.healthwell.com/nutritionsciencenews//NSN_backs/Jan_00/naturalnew\

s.cfm

- Fruits & Vegetables Slash Strokes

http://www.frc.mass.edu/rmorris/Cancer142/sld011.htm - photographs of

cruciferous vegetables

http://www.breastdoc.com/My_Breast_Health/Nutrition/Cruciferous_Vegetables/cruci\

ferous_vegetables.html

- Breast Health and cruciferous vegetables

http://www.dole5aday.com/nut_center/cabbage/CRUCIF.html -- Kurt and Casey

Collard, members of the cabbage family.

http://www.dole5aday.com

http://www.5aday.com

http://www.AboutProduce.com

 

http://vegetarianrecipe.com/default.asp