TFAs' effect on heart 'beyond dispute'
In addition, effects specific to trans fatty acids that are naturally present in dairy and meat and trans fatty acids produced as supplements for weight loss (conjugated linoleic acid) warrant further study, said Dutch researchers from the department of Health Sciences and the EMGO Institute for Health Care Research of VU University, in Amsterdam, and the Division of Human Nutrition of Wageningen University in a paper published in the European Journal of Clinical Nutrition.
TFAs are unsaturated fatty acids with at least one double bond in the trans configuration, whereas most unsaturated fatty acids have a ‘cis’ configuration. This means that the shape of the TFA is straighter, similar to saturated fatty acids. TFAs can be formed during the food production process (industrial) and can also be naturally present in dairy and meat (ruminant).
Focus of future research
In the paper, the researchers have summarised the evidence from human studies, examining the relationship between all TFAs and cardiovascular health. Besides industrial and ruminant TFAs, they also discussed conjugated linoleic acid (CLA), which originates from milk, but is now industrially produced and sold as a supplement intended to aid weight loss. Finally, they examined whether there were any unresolved important questions, and what the focus of future research should be.
By pooling data from the available studies, the researchers calculated that, gram for gram, all TFAs (regardless of origin) similarly worsen the blood lipid profile towards a higher risk of developing CVD. However, ruminant TFA consumption is very low, making the relevance of these fatty acids for cardiovascular health debatable. This is not the case for CLA, as recommended dosages of this supplement go up to six grams a day.
“To put this amount into context, the World Health Organization recommends TFA intakes below 1% of dietary energy, which corresponds to about 2.2 grams a day for someone with a daily energy need of 2000kcal,” they said.
Scientifically established
The authors concluded, from both observational studies on CVD and intervention studies on lipid profiles in the blood, that the adverse health effects of industrial TFA consumption have been scientifically established and limiting TFA consumption will likely reduce CVD risk.
They added: “Further studies into these TFAs is not a top research priority and future research should therefore focus on finding alternative ingredients, especially in the bakery sector, where replacing TFAs is particularly challenging without compromising product characteristics, such as baking stability.”
