(July 12) Imports of fruits, juices and nuts have an 18% share of American consumption of these items, compared to an 8.7% import share for vegetables, according to a new study by the U.S. Department of Agriculture’s Economic Research Service reports.

The study, published in July, shows that imports contributed heavily to a 20% rise in fruit and vegetable consumption in the past two decades.

The data showed that the import share of fresh and frozen fruits more than tripled from 6% in 1980 to 22% in 2000. The USDA report said the growth in vegetable imports was equally rapid, with the import share for fresh and frozen vegetables growing from 6% in 1980 to 14% in 2000.

Overall numbers show U.S. per capita food consumption rose from 1,800 pounds per year in 1980 to 2,000 pounds in 2000. In that 20-year span, the average share of imports in U.S. food consumption climbed from 7% to nearly 9%.

Imports’ share of consumption of tomatoes, potatoes, asparagus and onions also have grown. Asparagus showed one of the biggest changes in import share of any food, rising from just 11% in 1980 to 59% in 2000.

The author of the report, Alberto Jerardo, said more consistent supplies from foreign sources, improved shipping and storage technology and wider U.S. ethnic diet preferences aided imports during the 20-year span. In addition, the high value of the dollar in the past five years has made imports cheaper to U.S. consumers.

Jerardo said the declining tariffs as a result of the North American Free Trade Agreement have accelerated shipments from Mexico. The USDA said Mexico supplies 27% of U.S. fruit imports and 38% of vegetable imports. Latin American countries account for an additional 40% of U.S. imported fruits, mostly bananas, grapes and melons.

The study estimated that fruits, juices, nuts and vegetables account for 34% of the American diet, up from 33% in 1981-85. Consumption of animal products declined from 46% of the total diet in 1981-85 to 42.9% in 2000.