Trans fatty acids in adipose tissue and the food supply are associated with myocardial infarction

Metabolic studies have clearly shown that trans fatty acids (TFAs) elevate LDL and lower HDL cholesterol. Epidemiologic studies showed a relation between TFA intake and the risk of myocardial infarction (MI), but studies examining adipose tissue TFAs have not uniformly confirmed this. We performed a case control study examining both adipose tissue levels and dietary intake of TFAs and first MI. Between 1995 and 1997, 209 cases of first MI completed a 300-item FFQ and 79 had an adipose tissue biopsy; 179 matched controls completed the FFQ and 167 had a biopsy. During the course of the study (mid-1996), TFAs were eliminated from margarines sold in Australia. Cases biopsied before mid-1996 had greater levels of trans 18:1(n-9) (32% P < 0.03) and trans 18:1 (n-11) (23%, P < 0.001) than controls biopsied before mid-1996. After June 1996, there were no differences between cases and controls in any of the adipose tissue TFAs measured. Logistic regression showed that trans 18:1 (n-11) (P = 0.03) was an independent predictor of a first MI. Cases consumed 0.5 g/d (P = 0.002) more TFAs than controls. Subjects in the highest quintile of TFA intake had an OR for first MI of 2.1 (95% CI, 1.1-4.3), which was not independent of saturated fat intake. Apparent TFA intake from margarine was related to adipose tissue 18:1t[(n-9) and (n-10)] in 1995 (r = 0.66, 0.66, respectively). We conclude that TFAs in adipose tissue are associated with an increased risk of coronary artery disease and rapidly disappear from adipose tissue when not included in margarines.