A few weeks ago, I shared a study that found nutrients in the U.S. food supply are declining. Which could explain why millions of Americans, who prefer to be thin, are overeating to get more nutrients.
Another study found that industrial farming techniques – including the use of petroleum-based fertilizer – reduces nutrient levels in food, while dramatically increasing yields. This means we have abundant cheap food with lowered nutrient levels:
This article summarizes three kinds of evidence pointing toward declines during the last 50 to 100 years in the concentration of some nutrients in vegetables and perhaps also in fruits. It has been noted since the 1940s that yield increases produced by fertilization, irrigation, and other environmental means tend to decrease the concentrations of minerals in plants.
Jarrell and Beverly (1981) reviewed the evidence for this well-known “dilution effect.” Although their review has been cited over 180 times (60 times from 2000 on), few mentions of the dilution effect contain a reference, suggesting that the effect is widely regarded as common knowledge.
Common among scientists perhaps, but the public is unaware. When I share this among friends and readers there is a strong disbelief, with the most common response being - food is cheaper. Yes it is, because it has been hollowed out like a pumpkin and there’s nothing left on the inside.
And that makes it a struggle to get the message out. How do I explain the dilution effect to a public obsessed with everything but this – from diet programs to food labels to coupon cutting that encourages cheaper food?
I’ve written a lot about the benefits of shopping entirely at farmers markets, the difference between organic/GMO/seasonal, and how food is more important than working out. These topics have interested many people with many asking for more data.
Here is one piece, possibly the most important in explaining our obesity epidemic. The findings reveal farming practices and seed choice that have led to lower quality food. Compared on a nutrient-nutrient basis it can be a 1/3 drop in nutrient level for some foods.
This means that the typical person will need to eat 3x as much to obtain the proper nutrients. If true, that would provide the ideal explanation for our overweight problems. It’s not so much our sedentary lifestyle or even our poor choices in food, but our simple desire to get the nutrients our bodies need.
The report is worth a read and I will be sharing several more like it over the coming days.
“Nutrient levels in U.S. food supply eroded by pursuit of high yields”
Full Report (pdf)
2-page Newsletter Summary (pdf)
“High yields and jumbo produce deliver more water, starch, and sugar per serving, but less vitamins, minerals and antioxidants.”
4-page Research Summary (pdf)
“Farmers have doubled or tripled the yield of most major grains, fruits and vegetables over the last half-century. They have done so by capitalizing on the work of plant scientists, crop breeders and companies manufacturing a wide range of inputs—from fertilizer to water, pesticides, sophisticated machinery and diesel fuel.
But American agriculture’s single-minded focus on increasing yields over the last half-century created a blind spot where incremental erosion in the nutritional quality of our food has occurred. This erosion, modest in some crops but significant in others for some nutrients, has gone largely unnoticed by scientists, farmers, government and consumers.”