Commercial food has steadily become less nutritious for 2 reasons: soil depletion and crop selection. Modern intensive agricultural methods have incrementally impoverished the soil in which food is grown, as well as lacing the ground with toxic chemicals.
A British study of 20 vegetables found a 15–20% drop in various nutrients from 1930 to 1980. The US Department of Agriculture found “reliable declines” from 1950 to 1999 in all nutritional metrics for 43 different fruits and vegetables. Other studies have sussed similar results.
Efforts to breed new varieties of crops that provide greater yield, pest resistance, and climate adaptability have allowed crops to grow bigger and more rapidly, but their ability to manufacture or uptake nutrients has not kept pace with their rapid growth. ~ American biochemist Donald Davis
Phytonutrients are a vast array of compounds – over 25,000 – that confer health benefits. These crucial phytochemicals typically have a bitter taste, so growers select varieties that are sweeter but less nutritious.
Grapefruit exemplify. In 1985, Florida – the grapefruit capital of North America – produced 27 million boxes of white grapefruit, and 23 million boxes of the colored varieties. Today, Florida growers ship twice as many red and pink grapefruit as they do white ones.
White grapefruit is high in naringin, a bitter phytonutrient with anti-inflammatory, anti-ulcer, and anti-cancer properties. Pink and red grapefruit achieve their sweetness in large part by having substantially less naringin.
Eating fruits and vegetables without phytochemicals would be analogous to drinking the empty calories of a can of soda. ~ American nutritional biochemist Jed Fahey