Recently I returned to the bakery in the Sibillini mountains where they harvest their wheat by hand to buy some flour. None was for sale, so many people want to buy their flour they couldn't begin to meet the demand. When I asked a neighbour in a mountain village why people don't want supermarket flour he was astounded by my innocence. "Don't you realize the preservatives and insecticides they use to stabilize flour, sometimes for years? You wouldn't believe what some countries do to wheat."
His family goes to a mill where they buy the flour on the day that it is ground. This is because untreated flour only lasts a few weeks, or a month depending on the quantity and how it is stored. The wheat germ oil in flour lasts as long as fresh milk, without refrigeration.
So how can you ship flour on tankers across the world? Due to increased storage of food for longer periods and international trade, a host of beetles, mites, and weevils have adapted to 'food extension agents' (chemicals), and insects of tropical origins have established themselves in temperate zones. The grain seeds are treated before they are planted but let's consider just the storage.
It seems there are two main registered 'fumigants' for stored foods. One of these was called Methylbromide which was banned as of 2005 in developed countries and will be banned world wide as of 2015. The other, now predominant, is Phosphine. Phosphine was used as a pesticide in the 1930s, and E. Donahaye in his study for the journal Crop Protection, 19(2000)571-576, describes that insects gradually developed levels of resistance to the pesticide over the decades. Hence fumigation has to be longer. In fact, he states that fumigants are not totally residue free. The idea is that the gas penetrates and enters into the food product, sometimes for more than a week. At the end of the exposure treatment the gas is supposed to dis-absorb. Of course there are exposure guidance standards but Donahaye writes that "as long as phosphine is cheaply available without regulatory limitations on its use, CAs will continue to play a background role" (Donahaye 2000: 573). CA is Controlled Atmospheric Technology which seems preferable and is occasionally used for organic food. Fumigation does not have to be put on the label.
Another process used is 'radiation preservation' of grain. This has to be labeled and is not accepted in all countries. G. Hallman in his study for the Journal of Stored Products Research, 52(2013) 36-41, reports that the European Community collects data on irradiation and in 2011 claim no grains, pulses, nor their products had been irradiated. However, in Table 1, he includes Canada on the list of countries using irradiation for wheat and wheat products up to level 0.75 (kGy) and the USA up to level 0.59 (kGy). The more one looks into the process of storing wheat the more national divergences appear, although there are global standards. When we buy a wheat product it does not say where the wheat was stored, which may be different from where it was grown.
The icing on the cake are insecticides like Deltamethrin which are used as a top-dressing or layer treatment, meaning the top and the bottom parts of the stored grain are sprayed. There are world health exposure guidance values for Deltamethrin. In a stronger form, it has recognized neurotoxic effects (brain motor activity) and after reading about the laboratory animal studies of the damaging effects Deltamethrin I felt so depressed I could not help wondering why what we eat today has to be considered in relation to illnesses? Might there not be a better way?
Four additional treatments are sometimes in use depending on the duration and country the grain is stored in. There are global agencies setting health standards but the fact that some fumigants (or even pesticides) have lost their approval shows we are still learning. And no one knows the outcome of a century of ingesting this cocktail of chemicals.
These practices exist partly because we demand them. In the developed world many people have the luxury of choice. Like some mountain people in Central Italy we could choose to eat only fresh food, in season, from local sources. This means wheat wouldn't be eaten for more than six months of the year. But it's good to eat diverse types of carbohydrates as early people living in the mountains here did. There were many types of grains and beans grown at different times of year, in diverse climate conditions. 'Bread' and delicious pasta can be made from chestnut flour (or almonds or chick pea flour) as people did in Roman times. Use whatever is fresh and in season.
When my neighbour buys his flour from the artisan mill, the whole family of three generations spend one Sunday together using all the flour while it's fresh, making pasta which they dry, cakes which they wrap and put in tins, and bread that is so good -- they say -- it's delicious even if stale, toasted with drizzled olive oil on top...
The day the flour is ground it's made into their flour-based food for the whole month, as well as having a fun family activity. Surely that is a healthy option all round.