October 28, 2010

HIDDEN VARIABLES: Local & Organic Produce

Simple fact: Fresh produce loses nutritional value after it’s harvested.

Time matters. From the moment fruits and vegetable are picked their nutrients start to break down. According to a study by UC Davis, fresh produce grown within the US can often spend up to 5 days in transit to reach a distribution center after harvesting (while food imported from the Southern hemisphere can take several weeks to reach the US by ship). Once at a grocery store, “fresh” fruits and vegetables can then typically sit on a shelf for another 1 to 3 days, and then in your refrigerator for another week. By the time an average consumer actually eats their “fresh” fruits or vegetables, there are significantly less nutrients to be had compared to when the produce was harvested.

Pesticide-free local greens by SweetWater Organics at the Milwaukee South Shore Farmers Market. Greens are delivered to their within a day of harvest.

During a conversation with Jesse Hull, Director of Horticulture at Sweetwater Organics, Milwaukee, I learned a really interesting statistic - leafy vegetables for example, lose 50
 to 89% of their vitamin C within 24 to 48 hours after harvest.

One of the hidden advantages of buying locally grown produce is the short transit time between farm and market. For example, all of the greens grown at Sweetwater Organics are distributed within twenty-four hours of harvest to local restaurants and farmer’s markets in Milwaukee.

While their produce may be more expensive than food farmed further away (a bag of greens costs about $4) - it also likely contains at least TWICE as many nutrients.

It’s difficult for consumers to measure nutrient levels in the produce we buy, but several studies have shown that today’s conventionally farmed fruits and vegetables do not contain as many nutrients as they should. A study by Canada’s Globe and Mail states than an orange today contains ONE EIGHTH the amount of Vitamin A than those eaten by our grandparents 50 years ago.

Donald Davis, biochemist at the University of Texas at Austin calls this the “Dilution Effect”, and is typical of the majority of today’s commercially grown produce. Studies have shown that today’s organically grown crops are significantly more nutritious than non-organic crops. A comprehensive report published in the State of Science Review can be found here.

Farmers sell (and we buy) crops by weight, but rather than dollars per pound, really it’s the nutrients that should matter. Growing nutritious crops, and providing fresh food to consumers would have a tremendous impact on our health – definitely something to consider when evaluating the costs and benefits of buying organic and local produce, or starting up local farming initiatives.

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Check out our previous post: Western Queens Compost Initiative

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