British researcher Cathie Martin, who had developed genetically
modified (GM) purple tomatoes in 2008, is all set to conduct clinical
trials using the juice and soup from the GM tomatoes this year. The
purple tomatoes, which have been grown and are now being harvested in
Canada, would soon be arriving in the UK.
Talking to Down to Earth via email, Martin who works in department of
metabolic biology of the Norwich-based John Innes Centre, said, “We
plan to do a pilot study on patients at risk of cardiovascular disease.
All patients will be volunteers who will be informed that the juice is
from genetically-modified tomatoes. Recruitment will be restricted to
patients consenting to be volunteers in the full knowledge of what is
involved,” said the researcher. “We have funding only for a study
covering one year and markers for cardiovascular disease are the best
and can report any effects reliably during such short studies. We are
hoping to start recruitment within the next six months. Patients will be
given a seed free, juice or soup in the studies,” he added.
Purple tomatoes have been developed by inserting two genes from
snapdragon, a flower, in tomatoes to grow purple tomatoes that have
health protecting anthocyanins. Anthocyanins accumulated in the tomatoes
at levels higher than anything previously reported for metabolic
engineering in both the peel and flesh of the fruit. The fruit has an
intense purple colour. Anthocyanins are naturally occurring pigments
found at particularly high levels in berries such as blackberry,
cranberry and chokeberry.
Martin said, “There are some minor differences in structure of the
anthocyanins in the purple tomatoes compared to those in blueberries or
blackberries, but it is not known whether these differences impact
health to any extent.” The expert also said that the main anthocyanin
in the fruit of the purple tomatoes is naturally made in tomato leaves
and is nasunin, the anthocyanin in eggplant (brinjal) that is well known
for its health-promoting properties. “In addition, the consumption of
tomatoes does not usually involve consuming large amounts of sugar,
which is one of the disadvantages of berries (try cranberry juice
without sugar!),” he added.
Purple tomatoes also aim at fighting cancer
The scientists claim that purple tomatoes have been shown
anti-inflammatory effects compared to regular ones and also slow the
progression of soft-tissue carcinoma in cancer-prone mice. They also
have doubled the shelf life of the fruit.
The John Innes Centre (JIC), where these tomatoes were developed, is
an independent research centre in plant and microbial sciences with a
staff of over 800 people. Its research on purple tomatoes was funded by
the European Union (EU) and through the JIC’s strategic funding from the
Biotechnology and Biological Sciences Research Council. Purple
tomatoes were created using a grant of £900,000 from the European Union,
but were grown in Canada as GM regulations across Europe make
¬production too expensive.
Purple tomatoes developed by Cathie Martin’s team at John Innes Centre
The tomatoes were grown at the glasshouse of New Energy Farms in
Ontario, Canada, and are being harvested now. The grown variety is
expected to produce around 2,000 litres of juice. New Energy Farms was
asked to comply with all the regulatory requirements set by the Canadian
government for the cultivation of GM plants in glasshouses. All of the
plant material was incinerated following cultivation. The regulatory
authority could access to inspect the greenhouses at all times to check
on compliance. “By making juice, we have removed all the seeds from the
product to ensure that there was no unintended environmental release,”
explained Martin.
Anti-GM lobby’s objections
However, GMWatch, an independent international organisation and a
watchdog on development of genetic modification technology, alleged that
the Canadian authorities, by allowing growing of these GM purple
tomatoes in their territory, have been “endarkened” by the pro-GM
propaganda.
The organisation also said that there are over 200 types of fruits
and vegetables like red cabbage, red onions, and berries which have
red/purple pigments. Thus, one can have a diet rich in anthocyanins
without resorting to GM purple tomatoes. What Cathie Martin and her
colleagues have produced is totally unnecessary given the abundance of
anthocyanins in food plants, said representatives from GMWatch. Tho
clarify the same, they also cited an example of beetroot whose purple
colour is not an anthocyanin but another antioxidant.
They have also pointed out that the researchers don’t mention the use
of kanamycin (an antibiotic resistance gene) in their paper as the EU
had said that antibiotic resistance genes should be present in the final
GM plant. The GM watch researchers added that no generic toxicity
testing results, either short-term or long-term, of these tomatoes has
been published. Besides, no work has been done to see if nutrient
content is preserved during the time of extended shelf life. If the
nutrient content is not preserved, then it’s a rip-off in terms of what
the consumer is getting. They also said that these clinical trials are a
violation of EU regulations for genetically modified organisms (GMOs)
as human trials are being conducted before animal testing.
When asked about commercialisation of the modified tomatoes, Martin
said that the only way for consumers to be able to access this juice was
for it to be commercialised. For these reasons, the institute has
formed a micro-spinout to develop a realistic business plan for how to
could get the product to market. The researcher also said that the
company, Norfolk Plant Sciences, will also be working for regulatory
approval together with New Energy Farms, in Canada. “Human studies will
run parallel to their activities to get regulatory approval for
commercialisation, and if those studies indicate beneficial effects in
humans, we will seek a functional food label for the juice,” explained
Martin. He further asserted that the main aim of the team is to develop a
healthy product that is reasonably priced so that people with poorer
diets can access it – that is why everything has been done in tomato.
