The first OK to buy spinach after the big E. coli scare was for crops shipped out of Colorado or Canada. Then the Food and Drug Administration cleared California spinach -- except the suspect packages sent out by Natural Selection Foods.

Great. But why is three-quarters of all U.S. spinach grown in California, then shipped to markets as far distant as 3,500 highway miles? And especially at this time of year, when spinach can be grown successfully almost anywhere?

Agribusiness -- that's why. Supermarket chains, grocery wholesalers and fast-food producers all calculate that it is easier to maximize sales and profits by buying from big factory farms with reliable yields. Why fool with thousands of small farms or co-ops when you can get a standardized crop, packaged to precise specifications, priced at negotiated levels, trucked and delivered by known shippers? And when planes, ships and instant communications make it easy to import seasonal products from virtually anywhere on the globe?

Small wonder, then, that most of America's farmers must struggle to stay in business and on the land -- and hundreds of thousands have failed in the last decade. Locally grown food makes up less than 1 percent of the $900-billion food industry.

And for that, we all pay -- year in, year out, and far beyond the inconvenience of a single instance of contamination wiping a popular vegetable off grocery shelves in 50 states.

Pick your cost, they're all serious:

The loss of local farm families rips at the social fabric of communities, emptying church and school ranks, removing customers from local cafes, farm supply and hardware stores.

Much of America's most fertile farmland is around major cities, imperiled by suburbanization. Lost farms feed just one machine: sprawl.

Next, there's the gluttonous energy demand of a nationalized food system.  Industrialized agriculture requires huge amounts of fossil fuel for fertilizers, to power heavy farming machinery, for elaborate plastic wrappings, to refrigerate foods during shipping, and for the big trucks burning diesel fuel on their transcontinental trips.

Richard Pirog of the Leopold Center for Sustainable Agriculture at Iowa State University calculates that produce travels an average of 1,500 miles in three days to reach his state -- and even more to the East Coast.

By contrast, Pirog found food traveled an average of just 45 miles in a local food system of farmers selling to nearby restaurants, conference centers and institutions.

Then he compared the fuel and greenhouse gas emissions. Our continent-wide distribution system uses four to 17 times the fossil fuel, and emits five to 17 times the total carbon dioxide -- greenhouse gas -- emissions of a local system.

Can consumers help? Pirog believes so. He suggests point-of-sale labels -- he calls them ``ecolabels'' -- that indicate the energy impact of any given food. Local foods would show low impact, products such as Hawaiian pineapples, borne to market by gas-guzzling planes and trucks, a ``very high'' rating.

The British are ahead of us, focused on ``food miles'' and their consequence. Both the Labor and Conservative parties are behind a goal to reduce environmental and social costs of food transport 20 percent by 2012. The sophisticated British measure checks not just miles the food travels -- whether domestically or from abroad -- but energy used in production, time lost to traffic congestion, wear on the roads and ill health caused by air and noise pollution and accidents.

Our national agriculture policies tip blatantly to agribusiness' side. Still, U.S. regions can make a strong start at popularizing local food production. And many are: Check the growing number of farmers markets -- doubled to more than 3,700 in the last decade. Americans are increasingly voting with their grocery dollars, selecting the fresher, and often much more flavorful and nutritious produce grown locally. Smart restaurants are starting to feature fresh, local produce.

But supermarkets are mostly disinterested. The significant growth ticket for local agriculture may be institutions -- schools, hospitals, universities and (if we ever get so smart) the prisons where we hold 2 million inmates. Some hospitals and schools and many universities (often under pressure from students) have begun to buy fresh local produce and train their chefs to create dishes with locally raised ingredients instead of standardized heat-and-serve products.

But food policy can be a powerful connective issue, too. Many of us are already trying to burn less fossil fuel, to conserve energy to help avert global warming and its potentially calamitous consequences. Becoming ``locavores'' (people whose instinctive first choice is local foods) is a logical complement.

And it's not just gulping down one's spinach. It means tasting, savoring fresh foods and scorning mass production food ``products'' that are better fit for long-distance packaging than eating. It is a strategy that unites healthier bodies, reduced greenhouse gases, more resilient farms and a stronger and more self-sufficient regional economy. As American, I'd argue, as (fresh) apple pie.     

Neal Peirce's e-mail address is nrp@citistates.com