Impact of trans fatty acids on cardiovascular risk

The trans fatty acids present in our diet have two sources: the first is natural from bio-dehydrogenation in ruminants and the second, synthetic, from partial dehydrogenation of fats and oils. The major difference between the two types is the position of the double bonds on the carbon chain of the fatty acids. Several interventional studies have clearly shown that synthetic trans fatty acids have adverse effects on cardiovascular risk factors (increased LDL-cholesterol and decreased HDL-cholesterol). These findings are supported by most epidemiological surveys. However, these deleterious effects have not been observed with the natural trans fatty acids. The scarcity of epidemiological data would suggest a lack of effect but interventional trials are required to confirm this fact.