The study, carried out by the University of Arkansas and published in the Journal of Public Policy and Marketing, found that even consumers at risk for heart disease are confused by current nutritional information on trans fats without specific prior knowledge.
"In the absence of general knowledge about trans fat, especially without a specific understanding that 4 grams of trans fat is high, even motivated consumer… appear to misinterpret the meaning of trans fat info rmation," said Betsy Howlett, professor of marketing.
"Nutritionally motivated consumers lacking appropriate prior knowledge make inappropriate product judgments."
Trans fats Though trace amounts of trans fats are found naturally, in dairy and meats, the vast majority are formed during the partial hydrogenation of vegetable oil that converts the oil into semi-solids for a variety of food applications.
But reports have found trans fatty acids raise serum levels of LDL-cholesterol, reduce levels of HDL-cholesterol, can promote inflammation can cause endothelial dysfunction, and influence other risk factors for cardiovascular diseases.
The Nutrition Labeling and Education Act of 1990 (NLEA) extended the use of nutrition information on packaging.
It was extended in January 2006 to require that the amount of trans fat per serving be included.
Unlike other nutritional information, such as cholesterol and saturated fat, that of trans fats does not come with a percentage of recommended daily intake.
The FDA said this is because no scientific reports have recommended an acceptable amount.
However, this means consumers cannot interpret whether a product contains high levels of trans fats or not.
The study The researchers carried out two studies.
The first involved 153 participants diagnosed with diabetes that were given questions about snack crackers.
The test group was provided with information on trans fats prior to the questions.
It was found that, in the absence of induced or interpretive knowledge about trans fats, participants did not associate higher trans fat levels with different levels of nutrition or perceived cardiovascular risk.
The second study used 409 participants diagnosed with various cardiac-related conditions.
It considered consumers' motivation to process nutrition information.
Burton said: "When consumers were presented with a high trans-fat product, we found the highest purchase intentions and most favorable nutrition perceptions among consumers who were highly motivated to examine nutrition info rmation but did not have additional info rmation provided to them to help them interpret the trans-fat level correctly."
In both studies, claims such as 'low in trans fat' or 'zero trans fat' had a positive effect on nutrition perceptions.
Recommendations While this study was not externally funded or intended for use by the FDA for future guideline use, the researchers said the findings suggest the need to aid consumers in making an informed choice by including a footnote or reference value for trans fat.
The report said: "Overall, the results indicate that without appropriate consumer education programs, the addition of trans fat levels to the Nutrition Facts panel may have limited or even unintended consequences."
Source: Journal of Public Policy & Marketing Vol. 27 (1) Spring 2008, 83-97 "How Modification of the Nutrition Facts Panel Influences Consumers at Risk for Heart Disease: The Case of Trans Fat" Authors: Elizabeth Howlett, Scot Burton and John Kozup