Food fight: Is it the end of meat - and could purple tomatoes prevent cancer?

One of the most polarising debates of all hinges on meat.

READ MORE: Red meat and sugar consumption 'must halve' by 2050, say scientists

Research by Oxford University's Livestock, Environment and People (LEAP) project found that even if we cut all fossil fuel emissions immediately, we still would not reach climate change targets without also cutting food emissions.

The researchers are bringing their findings to Glasgow this week through an interactive 'Meat Your Persona' installation parked in Buchanan Street until until September 5 which will encourage the public to share their views as well as inviting them to learn how their own diet - and specifically meat consumption - could be impacting on their health and that of planet.

The 'Meat your Persona' exhibit invites members of the public to take a quiz to find out which of six diet types their eating habits put them into, and what the latest research tells us about meat, health, and the environment

Susan Jebb, a professor of population and diet health and co-director of LEAP, admits this can be a "difficult conversation" for people.

Michael Clarke, a postdoctoral researcher with LEAP, said there is "a lot of pushback" against the idea that meat consumption will have to drastically reduce - possibly by as much as 70 per cent in the UK, depending on the climate or health target - because what we eat is emotionally embedded in our national culture and psyche.

"Talking about the US, which is where I’m from, July 4 is a big national holiday where everyone goes out and barbecues," said Clark.

"If you were in the US on July 4 trying to say to people ‘hey, maybe you should eat less meat’, that would not be received particularly well."

Right now, the entire human food system - from what we eat, to how it is reared, processed, transported, and disposed of - accounts for 30% of the world's greenhouse gas emissions, with meat alone responsible for around half of that and up 80% of all agricultural land devoted to livestock or what we feed them.

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“Continuing to eat meat in the way and levels we currently do is not going to be compatible with Paris Agreement targets or biodiversity targets – basically you name it, meat consumption probably isn’t going to be compatible with it," said Clark.

“Some meat consumption will be needed for nutrition purposes, and some low income countries may still be able to increase their meat consumption, but reductions on a global scale are probably going to need to occur rapidly."

The future of food and agriculture is also in the spotlight at this year's British Science Festival, which begins on September 7.

Lisa Collins, a professor of animal science at Leeds University, said sustainability was not as simple as cutting out livestock altogether.

"One of the arguments is that we are consuming too much meat, we're over-reliant on animal products, and we need to move much more to the vegan agenda of cutting out animal products completely," said Collins.

"But actually, when we look at what a world would look like without animal agriculture at all, you see a number of side effects that are not positive."

Decades of intensive crop-based arable farming has depleted soils of essential minerals, but research led by Collins at the University of Leeds farm has shown that including livestock as part of a crop rotation has clear advantages, from compressing the soil and reducing the need for heavy machinery to depositing nitrogen- and phosphorus-rich faeces.

However, Collins, whose presentation explores where the food industry might be by 2051, believes the farms of the future may be located indoors where conditions can be controlled to maximise animal welfare - though your 'meat' might be reared in a petri dish.

"Some really cool developments that are happening at the moment allow us to mirror the environmental conditions of a field outside within an indoor environment," she said.

"From a scientific perspective that allows us to find out how to grow things more efficiently if they are being grown outdoors, but actually it goes beyond that because if we are able to replicate certain features of that outdoor environment indoors, that could also be a way of increasing our sustainability by improving the health and welfare of our animals.

"We may end up seeing our indoor farm environments become a bit more like our outdoor farm environments, with fewer animals overall being raised and those which are being used more in that regenerative farming sense where they're part of a broader crop rotation.

"The other thing that's coming through - we're seeing the early signs now - is basically meat cultured from animal cells, without having a fully live animal.

"It's all done essentially through a chemical process, not that different the production of quorn for example.

"It's often called lab-grown meat so we might see more of that.

"It seems that there is a bit of an appetite for trying this, and we certainly see at the moment a real appetite for meat alternatives in the market."

Lab-grown meat could give the carnivores of the future their steak and burger fix

Besides its environmental impact, excess meat consumption - especially red and processed meat - is linked to an increased risk of some cancers, heart disease and stroke.

UK guidelines recommend consuming no more than 70g per day on average - roughly equivalent to one pork sausage or two slices of roast beef.

READ MORE: Pandemic a 'wake up call' to tackle Scotland's obesity crisis 

"Too much red meat is not healthy, but there isn’t the same evidence for chicken and milk so those seem to be fairly neutral from a health perspective," said Clark, of the LEAP project.

"But where it becomes complicated is that the health impact of food is reflective of everything in the diet.

"So in the UK, excess consumption of red meat has been linked to a high-risk of diet-related diseases, but it also probably means that people aren’t getting enough fruit and vegetables.

"And not enough fruit and vegetables is also linked to diet-related diseases, so is it because we’re eating too much red meat - or because we’re not eating enough of the other stuff that is good for us?"

Western diets are characterised by excess red an processed meats and not enough consumption of fresh fruit and vegetables (Image: PA)

So could we make our diet healthier not only by eating more fruit and vegetables, but also engineering them with added health benefits?

Cathie Martin, a professor of plant sciences at the University of East Anglia, grabbed headlines 15 years ago when her lab genetically engineered tomatoes enriched with the purple pigment anthocyanin - an antioxidant which animal studies found cut the lifetime risk of cancer.

While the commercial production of genetically-modified crops is still banned across the UK, an application to sell the purple tomatoes and their seeds to farmers and amateur gardeners in the US is currently being considered by its Food and Drug Administration (FDA).

Approval is expected in February or early March next year, and Martin - who is also speaking at the British Science Festival - hopes it might nudge a rethink by UK regulators.

She said: "We showed that in animal models we could extend the lifespan of cancer-prone mice by 30% simply by changing the amounts of these pigments [anthocyanins] in the mouse's diet. No drugs, just by nutritional intervention.

"So that experiment does show that if you can improve the amount of these compounds that you can get from plants and put them into a package that people will eat, then you could have some major progress in terms of protecting health and maybe even in improving outcomes in people diagnosed with chronic diseases."

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The same pigments are already found in other plants such as blueberries, aubergines, red cabbage, or blood oranges, but Martin says the advantage of modifying tomatoes is that they also have huge commercial potential for the food industry in terms of ketchups, pasta sauces or pizza toppings - and might actually reach a wider range of consumers.

"You get the most benefit from having a very broad range of fruit and vegetables in your diet, but we're not going to get everyone giving up their fast food diets," said Martin.

"So if you are on a Western-style diet, a tomato is might be the only thing you're getting - and it's probably in ketchup."

Blueberries also contain the purple pigment anthocyanin

As well as GM tomatoes, research is also underway looking at how to use the more modern technique of genetic editing to "bio-fortify" tomatoes, for example with added vitamin D.

"Most people who are over-70 are vitamin D deficient anyway, regardless of the amount of sunlight they get, so this is something that would help older people to keep healthier in the later stages of life,"said Martin.

Unlike genetic modification - which introduces foreign DNA from other species - gene editing tweaks the existing genome.

But some plants are easier to edit than others: wheat - a huge component of Western diets - would be much more difficult to alter safely, says Martin.

Nonetheless, she believes gene editing technology could be key to improving the healthfulness of Western diets.

"It really is a benefit for introducing new traits into established varieties, " she said.

"It speeds up breeding, and I think that's where food companies and breeding companies are very interested because normally it takes 10 years to introduce and improve a new variety.

"But for many people the nutritional advantage on its own is not going to make them an awful lot of money. That's not a producer trait - it's a consumer trait.

"So if you could improve consumer traits in varieties that also gave advantages to farmers to produce them, then that would be a kind of win-win situation."