Trans fats are associated with greater risk of heart disease, death, BMJ study finds
Consumption of industrial trans fats, which are made by partially hydrogenating oil, was associated with a 34% increased risk in all-cause mortality, a 28% increased risk of dying from heart disease and a 28% risk of developing heart disease, researchers in Canada found after reviewing 41 observational studies that associated trans- and saturated fats with heart disease, stroke, type 2 diabetes and all cause mortality.
Because the studies were observational, the association cannot be deemed causal, the researchers note, adding the certainty between trans fat and coronary heart disease was “moderate” and for the other associations it was “low” or “very low.”
Nonetheless, it is notable that the associated increased risk was not observed between naturally occurring ruminant trans fats and cardiovascular heart disease and related deaths, the study authors point out.
The discrepancy “might reflect a true difference between sources or might be a function of consumption levels in most populations,” while “the average intake of industrial produced trans fats was about 2.5-fold that of ruminated derived trans fats,” the authors write.
They explain that the higher intake of industrial PHOs provides greater statistical power for detection of associations, which suggests a similar trend could be detected in ruminated trans fats if they were consumed more. It also might not.
The finding, which supports those of previous studies, comes less than a week after GMA shared parts of a food additive petition it sent to FDA asking for the continued “low-level use” of PHOs in a wide range of food categories.
FDA determined in June that PHOs are no longer considered generally recognized as safe and should be phased out unless specific exceptions are made and recognized by the agency through food additive petitions.
Are saturated fats off the hook?
The BMJ study also confirmed previous controversial study findings that saturated fats, which mainly come from animal products and some plants, are not associated with increased risk of death, heart disease, stroke or type 2 diabetes.
This finding contradicts existing dietary guidelines, which have come under fire recently, they say.
However, the study did find an association with death from CHD and saturated fats.
In a pooled analysis of 11 studies, not included in the quantitative synthesis, the researchers found replacing saturated fat with polyunsaturated fat or carbohydrate increased the risk of non-fatal heart attacks.
Based on these findings, the authors conclude that dietary guidelines for saturated and trans fats “must carefully consider the effect of replacement nutrients.”
