Declining Nutrition In Store Bought Food

A recent report finds significant nutrient decline in industrial ag food (no surprise there!). Kitchen Gardeners summarizes some of the findings:

Apparently produce in the U.S. not only tastes worse than it did in our grandparents' days, it also contains fewer nutrients - at least according to Donald R. Davis, a former research associate with the Biochemical Institute at the University of Texas, Austin. Davis claims the average vegetable found in today's supermarket is anywhere from 5% to 40% lower in minerals (including magnesium, iron, calcium and zinc) than those harvested just 50 years ago.

Today's vegetables might be larger, but if you think that means they contain more nutrients, you'd be wrong. Davis writes that jumbo-sized produce contains more "dry matter" than anything else, which dilutes mineral concentrations. In other words, when it comes to growing food, less is more.

the "genetic dillution effect," in which selective breeding to increase crop yield has led to declines in protein, amino acids, and as many as six minerals in one study of commercial broccoli grown in 1996 and '97 in South Carolina. Because nearly 90% of dry matter is carbohydrates, "when breeders select for high yield, they are, in effect, selecting mostly for high carbohydrate with no assurance that dozens of other nutrients and thousands of phytochemicals will all increase in proportion to yield.

Thanks to the growing rise of chemical fertilizers and pesticides, modern crops are being harvested faster than ever before. But quick and early harvests mean the produce has less time to absorb nutrients either from synthesis or the soil, and minerals like potassium (the "K" in N-P-K fertilizers) often interfere with a plant's ability to take up nutrients. Monoculture farming practices - another hallmark of the Big Ag industry - have also led to soil-mineral depletion, which, in turn, affects the nutrient content of crops.