Hitting the reset button
New science is re-shaping the way we think about dietary fats
Posted: October 24, 2013
The body of evidence continues to grow that natural trans fats are not harmful to human health at normal dietary levels.
This is according to an extensive review published recently in the British Journal of Nutrition, which discusses the current issues surrounding trans fat policy and related implications for health, industry and food labels. The review is based on the most up-to-date scientific evidence spanning several decades of research.
"In Canada, the trans fat content is required to be clearly labeled on food packages, whether it is from industrially-produced, partially hydrogenated vegetable oils, or from natural sources such as dairy fat and ruminant meats," says Dr. Flora Wang of the University of Alberta, a leading natural trans fats researcher who co-authored the review. "However, the emerging science consistently supports a neutral health effect of natural trans fat at levels achievable through a normal diet.
"The findings of the review are further evidence that there needs to be a clear distinction between natural and artificial trans fats in all forms of public health information, including food labels."
New science and analysis
The journal article features a wealth of critical analysis and discussion. Among the highlights:
Major population-based studies show no CVD risk. A quantitative analysis of 10 large-scale cohort studies compares the health implications of natural versus industrial trans fats consumed from the diet in populations in the U.S. and Europe. It concludes clearly that in contrast to dietary intake of industrially produced trans fat, consuming natural trans fat from foods currently available on the market does not affect the risk of cardiovascular disease (CVD) in healthy individuals.
Clinical trials further support CVD findings. Another quantitative analysis - this time of randomized clinical trials – continues the positive news for natural trans fats. It covers three decades of studies and examines the differences in CVD risk factors resulting from dietary consumption of industrial trans fat, natural conjugated linoleic acid (CLA) trans fat and other forms of natural trans fat. In all, data from 58 trials involving healthy subjects was considered – 11 focused on the effects of natural ruminant trans fats and the remainder focused on the effects of CLA supplements or industrial trans fats. Results indicate that consumption of natural trans fat from dairy products, at levels achievable in the regular human diet, does not have any effect on LDL or HDL in healthy individuals.
Pre-clinical studies indicate health enhancing potential. Cumulating evidence from animal studies adds support to these findings while also highlighting the potential for natural trans fats to actually enhance health. A leading example is the science related to trans-11 vaccenic acid (VA) – the major natural trans fat generally accounting for 70 percent of total natural trans fat in the diet. Several animal studies have shown that VA can reduce major CVD risk factors including blood levels of LDL, triacylglycerol and total cholesterol. Dairy fat enriched with VA and cis-9, trans-11 CLA has also shown neutral to beneficial effect on CVD risk.
The review authors also include Dr. Ye Wang and Dr. Spencer D. Proctor.
Click here for information on how to access the British Journal of Nutrition article.