The scientist who found that organic food is no healthier than conventional produce has been bombarded with hate mail from green activists.

Dr Alan Dangour, a nutritionist at the London School of Hygiene and Tropical Medicine, said hundreds of people have contacted him since his controversial literature review was published, accusing him of dishonesty and incompetence.

The research, which found no evidence that organic food was healthier than food produced with chemicals, could hit the £12bn-a-year organic industry at a time when sales are struggling in the recession.

“A lot of them have been unpleasant reading. They were saying I’m a quack, I should do something else and stop wasting my time, but also a lot of stuff saying I must have been funded by Monsanto or big industry,” Dr Dangour said.

The Food Standards Agency-funded study, which appeared in the American Journal of Clinical Nutrition last week, reviewed 50 years of scientific evidence and has polarised opinion between those for whom it confirms suspicions about organic and those who believe it is one-sided.

Rex Humphries of United Irish Organics in Northern Ireland said the report, which analysed 162 peer-reviewed studies, had been selective in what was published and “didn’t do anything new or meaningful”.

“There are any number of ongoing exercises that do quite clearly show milk from organic cows fed on clover sward tended to have more Omega 3 and CLAs (conjugated linoleic acid) in the milk.

“The medics would say these things are good for us and organic milk has more of these things in it,” he said.

“Other studies show that green vegetables grown organically have more vitamin C. I think it was a rather unfortunate statement for the FSA to come out with and it’s causing confusion — it’s not the whole truth, not balanced and is not taking into consideration new work and work that is ongoing.”

However, Mr Humphries said there had been no bad feedback since the report came out.

“The people who buy organic food are by and large thinking and discerning customers. They know why they are buying organic food and have made a conscious decision,” he said.

“If you look at wheat from North America it has been sprayed anything from four to seven times. Organic food does not have that cocktail of chemicals. The people who are wavering maybe haven’t researched it properly and I would urge people not to listen to half stories and half truths.”

The Soil Association has also labelled the FSA study “bad science”. It said that while all 162 relevant studies reviewed found organic to be higher in many nutrients such as beta-carotene, the review had concluded there were no important benefits from only 55 ‘high quality’ studies. Dr Dangour said he would have liked to have included new EU-funded research into organic nutrition published in April last year, but this came after the February cut-off date for his research period.

Another report from the EU study provisionally finding organic food is healthier is due to be published later this year. But Dr Dangour said the evidence he used was sufficient to come to a judgment about the nutritional content of organic food.