Many of the early studies that reported associations between saturated fat and cardiovascular disease had confounding variables that were not adequately controlled. In particular, the inclusion of trans fats within the saturated fat grouping has brought into question the usefulness of some of these studies. Full hydrogenation produces saturated fatty acids from polyunsaturated oil, and these can then be used by the food industry as a cheaper alternative to saturated oils. However, when hydrogenation does not proceed to completion, a range of artificial trans fatty acid intermediates are created. These trans fats were ignored in research during the formulation of the absurd cholesterol theory of cardiovascular disease (here) because little was known about their biochemistry. Although natural trans fats from dairy have always historically been in the human food chain, trans fats from partial hydrogenation are only a recent addition. In recent decades the intake of trans fats has risen as food adulteration by the big manufacturers continues unabated.
Recently the dangers associated with trans fat consumption have become known, thanks to the pioneering work by researchers such as Mary Enig and others. In particular, it has been reported that they increase the risk of cardiovascular disease significantly. For example, in a recent study published in the American Journal of Clinical Nutrition1, researchers used data from the Cardiovascular Health Study to assess the risk of cardiovascular disease from different patterns of fatty acids in phospholipid membranes. Patterns of fatty acids characterised by higher concentrations of trans fatty acids were associated with and increase risk of cardiovascular disease, which was attributable mainly to the higher risk of stroke. In a second cohort of postmenopausal women, a phospholipid profile containing high concentrations of trans fatty acids was associated with progression of coronary heart disease. These result therefore support previous findings as to the association between trans fats and increased risk of cardiovascular disease.
Of course this epidemiological research shows an association between trans fats and cardiovascular disease risk, and therefore cause and effects cannot be ascribed. However, animal studies and human intervention trials suggests that trans fats are a contributory cause of cardiovascular disease. Further, a phospholipid profile with high concentrations of trans fatty acids, as seen in this study, is likely a marker for consumption of a low quality diet containing overly processed foods which often contain high concentrations of trans fats. Food manufacturers have been deliberately deceitful with regard trans fats as they surreptitiously invent novel ways to hide them in their food products. The best antidote to this duplicitous behaviour is to avoid such products. This is easily achieved by avoiding processed foods and consuming a high quality diet devoid of processed and manufactured food. Traditional diets such as the Mediterranean and Okinawan diets are devoid of artificial trans fats because they contain no processed foods.
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