Now whether the change has been enough to make produce, including
spinach, of 50 years ago have ten times more nutrients in it is
debatable. But there is a good deal of evidence that current produce
is lower in nutrients than that grown in the past. Much lower.
This first quote comes from Australia:
"There is rapidly developing a soil shortage in the world. That is, we
are running out of good soil in which to grow food. This is because
soil needs time to reconstitute itself, and our corporate farmers have
no time. They want land that is producing, producing, producing. So
the age-old practice of alternating growing fields from season to
season is being abandoned or shortened. To make up for the loss of
time, chemicals are being dumped into the land in order to render it
The result is that we are eroding, down to a few inches really, in
some places, the available nutritive topsoil reserve. In other words,
we are growing more and more food in soil which has less and less
nutritional content. No irons. No minerals. Nothing which we count on
the soil to provide. Worse yet, we are eating foods filled with
chemicals which have been poured into the soil in a desperate attempt
to reconstitute it. In the long run these trace chemicals, which
remain in the body, are not health producing."
http://communitycauldron.com/farmersmarket/pest.html - The quote is
from the last article on the page. - From Community Cauldron, Byron
Pacific Shire, Australia
In the USA, the same process is taking place and the statistical
figures on the amount of nutritional decline in fresh produce is
The Kushi Institute of Becket, Massachusetts, has studied USDA
nutrient data from 1975 and 1997, and uncovered a disturbing trend:
calcium levels in 12 fresh vegetables have declined 27 percent, iron
levels have dropped 37 percent, vitamin A levels, 21 percent; and
vitamin C levels, 30 percent. - From an article by Kathryn Scharf -
website of "Communications for a Sustainable Future"
"A similar analysis comparing British nutrient data from 1930 and 1980
indicates reductions of essential minerals in both fruits and
According to the report, published in the British Food Journal (1997,
vol 99, no. 6, pp 207-211), average calcium content has declined 19
iron, 22 percent; and potassium, 14 percent in the 20 vegetables
compared. The report's author, Anne-Marie Mayer, now at Cornell
University, says, "Changes in agricultural practice during this time
could have contributed to the declinefor instance, soil compaction,
use of agricultural chemicals, disruption of soil life, or lack of
organic matter." - From the same source as the above.
This next bit has to do with brocolli. It is the end of an article
written by Matthew Engel of the Guardian. - - - "the answer is not
that we can give up broccoli. On the contrary, we have to eat four or
five times as much to get the benefit that would have been available
60 years ago. Eat MORE broccoli or else!" - - If you are not familiar
with the Guardian, it is a British publication.
http://www.ghorganics.com/Vegetable%20Nutrient%20Decline.htm - The
website is ghorganics.com and you can read the whole article there.
We have not reached the "ten times" decline level in produce yet in
this answer, but we are getting closer all the time.
USDA figures show a decline in mineral and vitamin content of several
fruits and vegetables between 1914, 1963, and 1992. Table 1 is a
summary of mineral decreases in fruits and vegetables over a 30-year
Table 1. Average changes in the mineral content of some fruits and
Mineral Average % Change
I hope that column of figures doesn't break up when I post this.
Fruits and vegetables measured: oranges, apples, bananas, carrots,
potatoes, corn, tomatoes, celery, romaine lettuce, broccoli, iceberg
lettuce, collard greens, and chard
From Sun Microsystems
Here is another article based on USDA nutritional figures. Since you
did ask for studies and statistics, I feel the two items I have
included here using USDA sources make the figures and statistics
presented about as official as you can get.
The title of the article is "Vegetables Without Vitamins" from Life
http://www.lef.org/magazine/mag2001/mar2001_report_vegetables.html - -
- - - Rather than giving quotes which may take thinks out of context
in this case, it may be best if you read the whole article and
consider it an integral part of this answer. You will also find two
anomalies. While the nutrient value of fruits and vegetables is on
the decline, there are two exceptions, carrots and pumpkins, which are
actually getting better.
Now while the answer didn't address spinach in particular, the overall
decline certainly includes that vegetable. You may tell your mom that
she is right, though she may have the percentage off by a bit and in
some cases not by that much at all. Since your mom is that aware of
the nutritional content of what she serves, maybe I'll start eating at
The websites used to compose the above are included in the text of the
If I may clarify anything, please ask.