'A report published in the Decmeber 2004 issue of the Journal of The American College of Nutrition has found a reduction in the nutritional content of fruits and vegetables occurring over the past 50 years. Modern agrigulture methods designed to improve traits other than nutrition may be to blame.
Donald Davis, PhD of the University of Texas at Austin's Department of Chemistry and Biochemistry and colleagues studied 43 vegetables and fruits using nutritional data for 1950 and 1999 obtained from the United States Department of Agriculture. They compared the crops individually and as a group, compensating for variations in moisture content.
The team found a decrease in the amount of protein, calcium, phosphorus, iron, riboflavin (vitamin B2) and vitamin C over the past 50 years, with riboflavin showing the greatest decline. Dr Davis commented on the findings: "It is much more reliable to look at average changes in the group rather than in individual foods, due to uncertainties in the 1950 and 1999 values. Considered as a group, we found that six out of 13 nutrients showed apparently reliable declines between 1950 and 1999."
Dr Davis explained that efforts to breed new varieties of crops that provide greater yield, pest resistance, and climate adaptability has allowed crops to grow bigger and more rapidly, but their ability to manufacture or uptake nutrients has not kept pace with their rapid growth.
He added, "Perhaps more worrisome would be declines in nutrients we could not study because they were not reported in 1950 -- magnesium, zinc, vitamin B-6, vitamin E and dietary fiber, not to mention phytochemicals. I hope our paper will encourage additional studies in which old and new crop varieties are studied side-by-side and measured by modern methods."'