MINNEAPOLIS — A study covering 30 years and involving 12,526 adults in the Minneapolis-St. Paul area found a downward trend in the intake of total fat, trans fat and saturated fat. However, mean intakes for both trans fat and saturated fat were still above recommended levels, and mean intakes for two kinds of omega-3 fatty acids were below recommended levels.

Results of the study were published Oct. 22 in the Journal of the American Heart Association. Researchers from the School of Public Health at the University of Minnesota in Minneapolis examined trends in fatty acid intake from 1980-82 through 2007-09. Twenty-four-hour dietary recalls were collected from people enrolled in the Minnesota Heart Survey, a series of six independent cross-sectional surveys designed to monitor cardiovascular risk factors in non-institutionalized adults living in the Minneapolis-St. Paul metropolitan area.

The per cent of calories from total fat decreased to a mean of 33.3% in 2007-09 from a mean of 38.7% in 1980-82. The 2010 Dietary Guidelines for Americans recommend daily total fat intake of 20% to 35% of total caloric intake.

Other decreases in the Minneapolis-St. Paul study came for saturated fat, to a mean of 11.4% in 2007-09 from a mean of 13.7% in 1980-82, and trans fat, to a mean of 1.9% in 2007-09 from a mean of 2.9% in 1980-82.

The 2010 Dietary Guidelines for Americans recommend daily saturated fatty acid intake of less than 10% of total caloric intake and trans fatty acid intake as low as possible. The American Heart Association, Dallas, recommends restricting saturated fatty intake to 5% to 6% of total caloric intake and trans fatty acid intake to less than 1%.

“Overall, the results of the present study demonstrate encouraging trends but offer evidence that current dietary recommendations for fatty acid intake are not being met in the population,” the researchers said.

The study also examined intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), two kinds of omega-3 fatty acids. The mean of daily intake of EPA fell to 0.04% of total caloric intake in 2007-09 from 0.06% in 1980-82. The mean of daily intake of DHA fell to 0.09% of total caloric intake in 2007-09 from 0.1% in 1980-82.

The U.S. Department of Agriculture and the American Heart Association both recommend increasing omega-3 fatty acid intake with a goal of consuming about 0.25 grams of DHA and EPA combined per day. To meet this recommendation, twice the current level of consumption is needed, the researchers said.