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  • From: "Tradingpost" <tradingpost@lobo.net>
  • To: livingontheland@lists.ibiblio.org
  • Subject: [Livingontheland] Industrial Farming is Giving us Less Nutritious Food
  • Date: Mon, 22 Jun 2009 21:26:26 -0600



Industrial Farming is Giving us Less Nutritious Food
http://www.motherearthnews.com/Sustainable-Farming/Nutrient-Decline-Industri
al-Farming.aspx

The commercially grown vegetables, fruits and grains that we are eating
today are significantly less nutritious than these foods were 100 years
ago, or even just 30 years ago.

We now have solid, scientific evidence of this troubling trend. For
example:

* In wheat and barley, protein concentrations declined by 30 to 50
percent between the years 1938 and 1990.
* Likewise, a study of 45 corn varieties developed from 1920 to 2001,
grown side by side, found that the concentrations of protein, oil and three
amino acids have all declined in the newer varieties.
* Six minerals have declined by 22 to 39 percent in 14 widely grown
wheat varieties developed over the past 100 years.
* Official U.S. Department of Agriculture (USDA) nutrient data shows
that the calcium content of broccoli averaged 12.9 milligrams per gram of
dry weight in 1950, but only 4.4 mg/g dry weight in 2003.

All of this evidence has been assembled and rigorously reviewed by Dr.
Donald R. Davis, a now (mostly) retired chemist from the University of
Texas.

So what’s causing these declines? The evidence indicates there are at
least two forces at work. The first is what agriculture researchers call
the environmental “dilution effect.” Davis notes that researchers have
known since the 1940s that yield increases produced by fertilization,
irrigation and other environmental means used in industrial farming tend to
decrease the concentrations of minerals in those plants. These techniques
give growers higher yields, and consumers get less expensive food. But now
it appears there’s a hidden long-term cost — lowered food quality.

For example, a study of phosphorous fertilizer on raspberries found that
applying high levels of phosphorus caused the yield to double and
concentrations of phosphorus to increase in the plants, but meanwhile
levels of eight other minerals declined by 20 to 55 percent!

The other force at work is what Davis calls the genetic dilution effect —
the decline in nutrient concentration that results when plant breeders
develop high-yielding varieties without a primary focus on broad nutrient
content. That’s what the studies of wheat, corn and broccoli confirm.

In fruits, vegetables and grains, usually 80 to 90 percent of the dry
weight yield is carbohydrates — sugars and starches (the last things we
need more of in the American diet). Davis says that when breeders (and
growers) specifically choose varieties for high yields, they are selecting
mostly for the highest amounts of carbohydrates.

“These studies suggest to me that genetic dilution effects may be common
when selective breeding successfully increases crop yield,” Davis says.
USDA data indicate that yields have increased an average of 1.8 fold for 24
vegetables and 1.3 fold for six fruits over the past 30 years.

What can we do? Vegetables and fruits are our richest sources of many
vitamins and minerals. It seems likely that those of us who grow food
gardens (or shop at farmers markets) will get more nutrient-dense foods if
we grow (or pay a premium for) older, lower-yielding heirloom varieties.
Odds are good that heirloom varieties may be more nutritious than current
supermarket fare. Plus, using organic methods such as moderate amounts of
slow-release fertilizers should help us get maximum nutrition from our
homegrown produce. And most important of all, Davis points out that the
nutrient declines in processed foods are much deeper and broader than the
declines in fresh, whole foods.

You can review the full study by requesting “Declining Fruit and
Vegetable Nutrient Composition,” HortScience, 2009; 44:15, at your local
library.









  • [Livingontheland] Industrial Farming is Giving us Less Nutritious Food, Tradingpost, 06/22/2009

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