A British study (though a bit dated) compares/details nutrient loss in foods from the 1940s to 1991. Just an example: You would have to eat 10 tomatoes grown in 1991 for the copper content of one tomato grown in 1940. Imagine what the difference is today! No wonder the world is seeing staggering obesity, as this is also thought to be a micronutrient problem -- people eat more quantity because the body is really looking for nutrients. Go through the study here; it contains a lot of great information! Quote: Minerals are what we are made of ... an amalgam of "stuff" of the earth and a quality often understood as "life force." It is improbable that we can function at our optimum on a physical, mental and emotional level if the foods we have available to us are deficient in vital minerals and trace elements.
We know that micronutrient deficiency leads to degenerative disease as well as obesity, but our mental/emotional health appears to suffer as well. Naturally, all this dysfunction sends us in the direction of modern innovative solutions (new markets and industries): the doctor's office, energy drinks, even fast food outlets. If we could only get our real food back!