What we eat is seen as more important than ever. And everywhere we are urged to go organic: we are told it is more nutritious, it improves animal welfare and helps the environment. In reality, that is mostly marketing hype.

In 2012 Stanford University’s Centre for Health Policy did the biggest comparison of organic and conventional foods and found no robust evidence for organics being more nutritious. A brand-new review has just repeated its finding: “Scientific studies do not show that organic products are more nutritious and safer than conventional foods.”

Likewise, animals on organic farms are not generally healthier. A five year US study showed that organic “health outcomes are similar to conventional dairies”. The Norwegian Scientific Committee for Food Safety found “no difference in objective disease occurrence.” Organic pigs and poultry may enjoy better access to open areas, but this increases their load of parasites, pathogens and predators. Meanwhile the organic regulation against feeding bee colonies with pollen supplements in low pollen periods along with regulation against proper disinfection leads to sharply lower bee welfare.

Organic farming is sold as good for the environment. This is correct for a single farm field: organic farming uses less energy, emits less greenhouse gasses, nitrous oxide and ammonia and causes less nitrogen leeching than a conventional field. But each organic field yields much, much less. So, to grow the same amount of wheat, spinach or strawberries, you need much more land. That means that average organic produce results in the emission of about as many greenhouse gasses as conventional produce; and about 10 per cent more nitrous oxide, ammonia and acidification. Worse, to produce equivalent quantities, organic farms need to occupy 84 per cent more land – land which can’t be used for forests and genuine nature reserves. For example, to produce the amount of food America does today, but organically, would require increasing its farmland by the size of almost two United Kingdoms. That is the equivalent of eradicating all parklands and wild lands in the lower 48 states.

But surely organics avoid pesticides? No. Organic farming can use any pesticide that is “natural”. This includes copper sulphate, which has resulted in liver disease in vineyard sprayers in France. Pyrethrin is another organic pesticide; one study shows a 3.7-fold increase in leukaemia among farmers who handled pyrethrins compared to those who had not.

Conventional food, it’s true, has higher pesticide contamination. Although it is still very low, this is a definite benefit of organics. However, using a rough upper estimate by the head of the US Food and Drug Administration’s Office of Toxicology, all conventional pesticide residues may cause an extra 20 cancer deaths per year in America.

This pales in comparison to the impact of organics. If all of the United States were to go organic, the cost would likely be around $200 billion annually from lower productivity. This is money we can’t spend on hospitals, pensioner care, schools, or infrastructure.

Such economic impacts also have life and death consequences. Research shows that when a nation becomes $15 million poorer, it costs one “statistical” life, because people are able to spend less on health care and good food. This means that going organic in the US will kill more than 13,000 people each year. Scaling these findings to the UK would indicate that while extra pesticides in conventional cause perhaps four deaths each year, the UK going completely organic would cost ￡22 billion per year, resulting in more than 2,000 extra deaths each year.

Organics is a rich world phenomenon, with 90 per cent of sales in North America and Europe. Despite a fivefold increase in sales over the past 15 years just 1 per cent of global cropland is organic. That’s because almost half of humanity depends on food grown with synthetic fertilisers, excluded by organic rules. Norman Borlaug, who got the Nobel Prize for starting the Green Revolution, liked to point out that organic farming on a global scale would leave billions without food. “I don’t see two billion volunteers to disappear,” he said.

Essentially, organic food is rich people spending their extra cash to feel good. While that is just as valid as spending it on holidays, we should resist any implied moral superiority. Organics are not healthier or better for animals. To expand to any great scale would cost tens of billions of pounds while killing thousands. Indeed, a widespread organics revolution will increase environmental damage, and cut global forests.

When the designer Vivienne Westwood famously exclaimed that people who can’t afford organic food should “eat less” she may have had the best intentions. But she was also incredibly out of touch. The rest of the world needs more and cheaper food. That isn’t going to be organic.