People are eating less trans-fatty acids than they were two decades ago, finds a new study, which comes shortly after the Food and Drug Administration's proposed regulation requiring the fats to be labeled on food products from 2006.
Predominantly found in hydrogenated vegetable oil, trans-fatty acids are thought to increase levels of bad cholesterol and in recent years, consumers have become more concerned about the potential health hazards of trans-fatty acids in the American diet.
The results of the study, conducted at the University of Minnesota and published in this month's Journal of the American Dietetic Association, may partially explain the decrease in coronary heart disease in the United States since the late 1960s, say the researchers.
"Americans are making great strides in improving cardiovascular health by consuming less trans-fatty acids. Awareness of the harmful effects caused by these acids is critical to improving health," said Lisa Harnack, associate professor of epidemiology at the University of Minnesota School of Public Health and principal investigator of the study.
"This study magnifies the fact that there are good and bad choices people can make concerning fat and oil consumption in their diets," she added.
Little previous research had been done on trans-fatty acid intake in the United States.The study examined trends in trans-fatty consumption from 1980-1982 and 1995-1997 using data collected as part of the Minnesota Heart Survey, a population-based study in a large urban area of cardiovascular risk factors, morbidity, and mortality.
Downward trends in dietary intake of trans-fatty acids were found both between 1980-1982 and 1995-1997. For men, intake of total trans-fatty acids declined from 8.3g per day in 1980-1982 to 6.2g per day in 1995-1997, reported the scientists.
Similar declines were also seen when looking at the fats as a percentage of energy. Mean intake of total trans-fatty acids decreased from 3.0 per cent of total energy in 1980-1982 to 2.2 per cent of total energy in 1995-1997.
The researchers concluded that intake of trans-fatty acids is on the decline, but "consideration should be given to additional changes in the food supply and consumer food choices that may result in further reduction in consumption of trans-fatty acids."