Trans-fatty acid levels in erythrocytes in Europe.

Purpose: High, but not low levels of trans-fatty acids (TFA) in erythrocytes are associated with increased mortality. Current erythrocyte TFA levels in Europe are not known.

Methods: TFA levels in samples submitted by physicians for erythrocyte omega-3 fatty acid analyses are reported, as analysed with a method (HS-Omega-3 Index) previously used in pertinent prospective epidemiologic studies. From Germany, 6754 samples were included from 2008 through 2015, and 496 samples from 10 other European countries.

Results: In Germany, mean levels of C16:1n-7t, a marker for dairy and meat intake, decreased, as did mean levels of industrially produced (IP)-TFA, as did the percentage of individuals with IP-TFA > 1.04 %. Mean levels of IP-TFA in Austria and Switzerland were low before and after measures were taken to reduce them. Average levels of C16:1n-7t were low, and at levels associated with increased risk of death in previous studies. A limitation of our study is that samples were not obtained in a specific or representative manner.

Conclusions: Levels of IP-TFA appear to be decreasing, as are those of ruminant-derived C16:1n-7t, a marker for dairy and meat intake. Few individuals had high levels of IP-TFA above a safe range, while many had low levels of C16:1n-7t. Our data argue against further action against TFA in the countries studied. More systematic biomarker-based studies are needed.