Independent studies conducted in the United States, Canada, the United Kingdom and many other countries show that the nutrient content of our food has fallen substantially over the past few decades.
The tables below show the fall in the nutrient content of broccoli and potatoes sold in Canada between 1951 and 1999:
Broccoli, Raw, 3 spears, 93g. 100/93=1.08
Potatoes, one potato, peeled before boiling, 136g. 100/136=.74
Vegetables Without Vitamins. Life Extension magazine, March 2001.
Changes in USDA Food Composition Data for 43 Garden Crops, 1950 to 1999. Donald R. Davis, PhD, FACN, Melvin D. Epp, PhD and Hugh D. Riordan, MD. Journal of the American College of Nutrition, Vol. 23, No. 6, 669-682 (2004).
Modern Miracle Men – Article from Cosmopolitan presented to the 74th United States Congress by Senator Duncan U. Fletcher (D-FL) in June 1936.
Dirt Poor: Have Fruits and Vegetables Become Less Nutritious? Scientific American.
Nutrient Changes in Vegetables and Fruits, 1951 to 1999. Compiled by Jeffrey Christian.
Apparent Nutrient Changes in Government Data for a Selection of Fruits & Vegetables: 1951 vs 1999. L. A. Piché PhD RD, Associate Professor, Nutrition Program, Brescia University College.
The mineral depletion of foods available to us as a nation (1940-2002) – A review of the 6th Edition of McCance and Widdowson. Thomas D. Nutr Health. 2007;19(1-2):21-55.
Meat and diary: where have all the minerals gone? Food Magazine 72, pub. by The Food Commission, UK. Jan/Mar 2006.
Dutch vegetables have fewer vitamins. DutchNews.nl. Wednesday 16 April 2008
Changes in the mineral and trace element contents of cereals, fruits and vegetables in Finland. Journal of Food Composition and Analysis Volume 20, Issue 6, September 2007, Pages 487-495.