I tend to buy locally produced food if possible, such as that sold at my local farmers' market - for ethical, as much as health, reasons.
The large supermarket chains in the U.K. have too much power; they compete with one another to offer the lowest prices but, in the end, lower prices just equals lower standards, not lower profits for them: The cost of these "savings" are passed on to the suppliers, who want to make a profit too, and so cut their own costs accordingly, using ever cheaper farming methods and ingredients, minimal quality control, cheaper, often temporary (and, therefore, less skilled) labour, and so on.
I don't necessarily blame consumers for taking advantage of the supermarkets' offers, that's just human nature (greedy f*ckers), but it seems a false economy to me - we end paying for it anyway; through taxes to clean the environment, or fund the hospitals that have to deal with the chronic heart disease and cancers, or paying benefits to workers whilst out of season etc.
oops. Is that off-topic? Right, the health benefits of organic foods; I found this piece in yesterday's Guardian (newspaper):
Organic food can help you sleep, keep you slim and boost your immune system - if you are a rat.
Scientists at the Danish Institute of Agricultural Sciences experimented with 36 rats, feeding one group organic food, another group food grown conventionally with high levels of fertiliser and some pesticide, and a third group minimally fertilised food. They say the rats fed organic food were measurably healthier, in that they slept better, had stronger immune systems and were less obese.
Dr Kirsten Brandt of Newcastle University's school of agriculture, who helped to design the study, said: "This study doesn't prove anything about which food is better than the other, but it does show that it can make a difference."
The results have been submitted to a scientific journal but have not yet been published. They were released yesterday by the Danish Research Centre for Organic Farming, which funded the study. It said: "In all cases where differences were observed there was a beneficial effect of the organically grown diet. This indicates a positive effect of organically grown foods as compared to conventionally grown food."