A crop of genetically modified purple tomatoes designed to fight cancer has been grown and harvested in a greenhouse in Leamington, Ont.

The purple tomatoes have been genetically modified to have a higher amount of anthocyanins, an antioxidant found in blueberries, blackberries and plums. It's what gives those fruit their purple colours. Anthocyanins are also said to fight cancer.

New Energy Farms, based in Leamington, the tomato capital of Canada, grew the crop for professor Cathie Martin, a plant biologist at the John Innes Centre, in Norwich, U.K.

“It looks very similar to normal tomato crops. You really wouldn’t know any difference, apart from the colour of the fruit,” said New Energy Farms CEO Paul Carver.

The tomatoes were grown in a controlled greenhouse environment and handpicked. The juice was extracted and the seeds and plants were then burned to prevent cross-contamination.

The 2,000 litres of purple tomato juice processed from the crop will be sent to British heart patients in early February.

Martin's research has found the tomatoes rich in anthocyanins help fight cardiovascular disease, as well as cancer.

"When mice [with cancer] were fed a diet supplemented with purple tomatoes, they lived 30 per cent longer than those with a diet supplemented with red tomatoes,” she said.

Martin said the purple tomatoes also have anti-inflammatory properties.

Martin said research shows “complementary health advantages for people diagnosed with major chronic disease, particularly cancer.”

“We’re not saying this is a standalone therapy,” she said.

Martin’s team had New Energy Farms grow the tomatoes in Canada because European regulations governing genetically modified foods are stricter than they are here

“Canada was an unbelievably good choice because you have a very enlightened view of regulatory approval,” Martin said.

“It was easier to do this in Canada than elsewhere,” said Carver, whose company also has facilities in Europe.

Martin said because blueberries are seasonal and more expensive, growing the genetically modified tomatoes is a better option.

'Just a gimmick'

Not everyone supports genetically modified foods.

Shiv Chopra, who was a senior scientist for Health Canada for 35 years, said genetically modified foods are “just hypothetical claims to sell a product.”

“These are all gimmicks just to make a special controlled product so they can control patents,” Chopra said.

The purple tomatoes look similar to the red ones, except for the colour. (Courtesy Cathie Martin/John Innes Centre)

Chopra said once a company patents a crop, it can "go and destroy everything else" and only the genetically modified crop would be left for sale.

Chopra said genetically modified foods lead to “monocultures,” defined as the cultivation or growth of a single crop.

“A monoculture in nature doesn’t survive. It’s susceptible to diseases,” Chopra said. “The danger is, you will end up losing that whole line of product.”

Martin said “there is nothing inherently dangerous about the technology.”

“All we’re trying to do is provide consumers with choice,” Martin said. "I believe very strongly that if there’s a benefit to what we’ve done, I want to get it out there to consumers.

“There will be people who don’t want it and that’s fine by me.”