Consumption of trans fatty acids and cardiovascular risks:: Aquitaine survey

This report addresses firstly the controversy about possible health hazards of dietary trans fatty acids (TFA) stemmed from many studies performed since the 90's. Dietary TFA ore supposed to increase the risk of coronary heart disease (CHD). From the first data, a positive relationship was found between the energy intake from 9t-18:1 (range: 3.7 to 10.9%) and LDL-cholesterol concentrations. This trans isomer, in some cases, can also lower HDL-cholesterol concentrations. Epidemiological studies on associations between TFA intake and risk of CHD are still not conclusive. Moreover, methods of assessing TFA intake have certain weak points. It would be desirable to combine dietary survey methods with biochemical indicators of long term fatty acid intake such as the adipose tissue, Results of a French study ore reported in the second part The aims of this study were to assess the TFA intake in Aquitaine and to examine the relationship between the presence of TFA in adipose tissue and blood plasma, and LDL- and HDL-cholesterol concentrations in plasma of non-pregnant (n = 97) and pregnant (n = 90) women. Through dietary 7-days records, the mean TFA consumption was 2.7 g/d/pers., which represented 1.3% of energy intake. The TFA level was 2.3 +/- 0.5% of total fatty acids in adipose tissue. Based on the 18:1 trans content of adipose tissue, the population trans consumption was clearly lower than those of the other European countries, USA and Canada. The composition of adipose tissue TFA was analyzed relative to the dietary sources of TFA, ruminant fats and partially hydrogenated oils (PHVO). The Delta 11t 18:1 isomer was the most prevalent in adipose tissue like in ruminant fats. Estimates of relative contribution to TFA intake were 60% from ruminant fats and 40% from PHVO. This pattern contrasts sharply with those established for Canada and the United States where PHVO is reported to be the major dietary source of TFA.