Strictly embargoed to 0001 hours,
Wednesday 7th December 2005
Cancer, genes and Broccoli - study of genetic differences
in cancer protection
broccoli developed by traditional plant breeding methods
People who gain less protection from cancer
by eating broccoli may be able to compensate for the difference
in their genetic make-up by eating ‘super broccoli’,
a variety with higher levels of the active plant chemical
sulforaphane, or by eating larger portions.
Lead scientist on the new research, Professor Richard Mithen
of the Institute of Food Research (IFR), said: “Eating
a few portions of broccoli each week may help to reduce the
risk of cancer. Some individuals, who lack a gene called GSTM1,
appear to get less cancer protection from broccoli than those
who have the gene.
“Our studies suggest that this may be because if you
lack the gene you cannot retain any sulforaphane inside your
body, it is all excreted within a few hours. However, if you
consume larger portions of broccoli, or broccoli with higher
levels of sulforaphane, such as the ‘super broccoli’,
you may be able to retain as much sulforaphane in your body
as those who have the gene. Eating larger portions may have
additional benefits since broccoli is also a rich source of
other vitamins and minerals”.
|two varieties of broccoli shows
standard broccoli on the left (“Iron”), and
‘super broccoli’ on the right
Broccoli is the main source of natural compound
sulforaphane. It belongs to the crucifer family of plants
which includes the brassica vegetables cabbage, cauliflower
and Brussels sprouts, and the closely related Chinese cabbage
and turnips. Other crucifers include watercress and salad
rocket. The most distinctive characteristic of crucifers is
that their tissues contain high levels of glucosinolates.
When they are eaten, glucosinolates are broken down to release
isothiocyanates. There is a well established body of evidence
to show that isothiocyanates are among the most potent dietary
Sulforaphane is the main isothiocyanate derived from broccoli.
‘Super broccoli’ contains 3.4 times more sulforaphane
than standard varieties. It has been developed by traditional
plant breeding methods.
Fifty per cent of the population lack the GSTM1 gene. While
these people may gain less cancer protection from consuming
broccoli, it is likely that they gain more cancer protection
from eating other types of crucifers, such as cabbages and
Chinese cabbage. So the best advice is to eat a mixture of
This research was funded by IFR’s Core Strategic Grant
from the Biotechnology and Biological Sciences Research Council
and by the University of Nottingham and Seminis Inc. It is
part of ongoing research at IFR to identify the optimal levels
of a range of food compounds for human health.
Notes to Editors
- Please contact Zoe Dunford for more information, photos
and to arrange interviews: firstname.lastname@example.org,
tel. 01603 255111 / 07768 164185
- Photos available of ‘super’ broccoli growing.
- The mission of the Institute of Food Research (www.ifr.ac.uk)
is to undertake international quality scientific research
relevant to food and human health and to work in partnership
with others to provide underpinning science for consumers,
policy makers, the food industry and academia. It is a company
limited by guarantee, with charitable status, grant aided
by the Biotechnology and Biological Sciences Research Council
- The University of Nottingham is one of the UK's leading
universities and is consistently ranked in the top ten.
With recently opened campuses in both China and Malaysia,
it has more than 31,000 students in total, including 6,000
international students from more than 100 nations. The University
has 33 top-rated teaching subjects and research awards for
2004-5 topped £100m - a testament to its reputation
for world-class research. The Sunday Times University Guide
2005 said: "At the cutting edge both academically and
in terms of revenue raising, Nottingham is one of the finest
institutions in the country."
- Seminis Inc. (www.seminis.com)
is the world's leading developer, producer and marketer
of vegetable seeds. Its products are designed to increase
crop yields, reduce dependence on agricultural chemicals,
limit spoilage, offer longer shelf life, and produce vegetables
and fruits with better taste and nutritional content. Seminis
has established a worldwide presence and global distribution
network that spans 150 countries. It is developing commercial
varieties of broccoli with enhanced levels of glucosinolates
- Full reference for the paper:
Glutathione S-transferase M1 polymorphism and metabolism
of sulforaphane from standard and high-glucosinolate broccoli.
Am J Clin Nutr; 82: 1283: 2005
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