Eating more vegetables has been touted as a way to make us healthier. But what happens if those vegetables aren't as nutritious as they used to be? This disturbing news came from a study of the nutrient content of US vegetables since 1950. Researchers found declining nutrient levels in many common vegetables.
The University of Texas and the Bio-Communications Research Institute studied 43 vegetables, comparing 13 components, such as protein, calcium, and vitamin A, in 1950 and again in 1999.
According to their statistical analysis, there has been a significant decrease in major minerals such as calcium (-16 percent), phosphorus (-9 percent), and iron (-15 percent). Two of the five vitamins analyzed -- riboflavin (-38 percent) and ascorbic acid (-15 percent) -- also showed decreases. There was a decrease in protein content (-6 percent), as well.
However, there were increases of some nutrients in some vegetables, suggesting the reason is not due to broad practices, such as farming techniques, or large changes in soil composition. Instead, the decline may be related to growing new cultivars that "trade off" nutrient composition for other characteristics, such as yield, growth rate, and pest resistance. If this is the case, organic practices alone can't reverse this trend, but perhaps growing older, nutrient-rich vegetable varieties can.
For more information on this research, go to: Journal of the American College of Nutrition.