Health effects of trans-fatty acids: Experimental and observational evidence

Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
European journal of clinical nutrition (Impact Factor: 2.71). 06/2009; 63 Suppl 2(Suppl 2):S5-21. DOI: 10.1038/sj.ejcn.1602973
Source: PubMed


Growing evidence indicates that trans-fatty acids (TFA) adversely affect cardiovascular health. As part of the World Health Organization (WHO) Scientific Update on TFA, we reviewed the evidence for effects of TFA consumption on coronary heart disease (CHD).
We searched Medline publications examining TFA consumption and CHD risk factors or outcomes, emphasizing results of studies in humans. We evaluated and synthesized evidence from both controlled feeding trials evaluating risk factors and long-term observational studies evaluating risk factors or clinical outcomes, each of which have complementary strengths and limitations, to enable the most robust and reliable inferences of effects.
The effects of TFA consumption on risk factors most consistently seen in both controlled trials and observational studies included adverse lipid effects (for example [upward arrow] low-density lipoprotein cholesterol, [downward arrow] high-density lipoprotein cholesterol (HDL-C), [upward arrow] total/HDL-C ratio), proinflammatory effects (for example [upward arrow] tumor necrosis factor-alpha activity, [upward arrow] interleukin-6, [upward arrow] C-reactive protein) and endothelial dysfunction. These effects were most prominent in comparison with cis unsaturated fats; adverse effects on total/HDL-C and endothelial function were also seen in comparison with saturated fatty acids (SFA). TFA may also worsen insulin sensitivity, particularly among individuals predisposed to insulin resistance; possible effects on weight gain and diabetes incidence require further confirmation. Five retrospective case-control studies and four prospective cohort studies demonstrated positive associations between TFA consumption and CHD events. A meta-analysis of prospective studies indicated 24, 20, 27 and 32% higher risk of myocardial infarction (MI) or CHD death for every 2% energy of TFA consumption isocalorically replacing carbohydrate, SFA, cis monounsaturated fatty acids and cis polyunsaturated fatty acids, respectively. The differential effects of specific TFA isomers may be important but are less well established. The available evidence indicates that trans-18:1 and particularly trans-18:2 isomers have stronger CHD effects than trans-16:1 isomers. The limited data suggest that the experimental effects of ruminant and industrial TFA are similar when consumed in similar quantities, but very few persons consume such high levels of ruminant TFA, and observational studies do not support adverse CHD effects of ruminant TFA in amounts actually consumed.
Controlled trials and observational studies provide concordant evidence that consumption of TFA from partially hydrogenated oils adversely affects multiple cardiovascular risk factors and contributes significantly to increased risk of CHD events. The public health implications of ruminant TFA consumption appear much more limited. The effects of specific TFA isomers require further investigation.

Full-text preview

Available from:
  • Source
    • "These products are also substantial sources of fat which is associated with the presence of saturated fatty acids (SFA) and trans fatty acids (TFA). These compounds are responsible for an increasing level of plasma cholesterol, mainly LDL-cholesterol which is implicated in increasing the risk of development of cardiovascular diseases and type II diabetes [Mozaffarian et al., 2009]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The main aim of this study was to determine consumer preferences by school-aged children and selected quality indicators of new, highly nutritive grain bars designed as a snack during school break. Consumer acceptance was evaluated by the scaling method using a fi ve-point mimic hedonic scale. Triacylglycerols (TAG) and fatty acids (FA) composition was assayed in fats extracted from the designed bars (fresh and stored) by gas chromatography. Contents of oxidation and hydrolysis products were determined using peroxide value (PV), anisidine value (AnV), and acidic value (AV). The antioxidant activity of the ethanolic extract from bars was measured by scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and Folin-Ciocalteau methods. The overall liking of bars was high (4.05 pts on average in the 5-point scale). The majority of children (71%) scored the designed bars as tasty and very tasty. The designed products contained 22.3% of fat with about 44 g/100 g FA of valuable fatty acids, e.g., short-chain saturated fatty acids (SCSFA), monounsaturated fatty acids (MUFA) and odd and branched chain fatty acids (OBCFA), recommended for young organisms. The content of CN52, CN54, CN50 and CN46 triacylglycerols (TAGs) (about 49 g/100 g TAG) was due to both milk and cocoa fat. Storage of bars did not influence their content of oxidation and hydrolysis products, resulting from a substantial content of total phenolics (TPC) (53.64 mg GAE/100 mL of extract) and DPPH scavenging activity at the level of 24%. The designed bars may be an interesting confectionery product for children and an alternative to snacks currently available in school shops.
    Full-text · Article · Oct 2015 · Polish Journal of Food and Nutrition Sciences
  • Source
    • "On the other hand, t9-18:1 has been associated with both negative (Gebauer et al., 2011; Wang et al., 2012) and positive (Brenna & Kothapalli, 2014; Tyburczy et al., 2009) effects on CVD risk factors in rats, thus further studies are required to ascertain its health effects. High levels of iTFA, which is a rich source of t10-18:1, have been associated with coronary artery disease in humans (Gebauer et al., 2011; Mozaffarian, Aro, & Willett, 2009). In addition, feeding rabbits butter enriched with t10-18:1 increased plasma levels of very low density lipoprotein cholesterol, low density lipoprotein cholesterol and aortic lipid deposition (Roy et al., 2007), which are risk factors for coronary heart disease and atherosclerosis. "
    [Show abstract] [Hide abstract]
    ABSTRACT: In addition to being an important source of macro- and micronutrients, beef can also be a source of trans (t)-18:1 fatty acids (FA). Overall, trans-FA have been associated with an increased incidence of cardiovascular disease in humans. Recent research has, however, shown that t-18:1 FA are a group of distinct isomers which elicit differential biological effects. The current review examines the potential of different nutritional strategies to enrich potentially beneficial or deplete detrimental t-18:1 isomers in beef. The possible contribution of seemingly beneficial t-18:1 isomers to global food and nutrition security is highlighted. The review also describes the importance of developing a regulatory framework to govern the consumption of individual t-18:1 isomers to enhance and sustain their contribution to food and nutrition security.
    Full-text · Article · May 2015 · Food Research International
  • Source
    • "Feeding based on oat hay leads to a n6/n3 ratio value slightly greater than the recommended limit. Epidemiological studies have reported that the trans-FA consumption can be harmful to human health (Mozaffarian et al. 2009), in particular C18:1 t-10 consumption is related to unhealthy changes in plasma lipoprotein profiles in animal models (Roy et al. 2007). Based on trans C18:1 isomer profile, feeding with olive leaves and S. tenacissima diet might be the healthiest option to lower the Σ (t6 to t16 (excluding vaccenic acid)) compared to other diet treatments. "

    Full-text · Article · Jan 2015 · Animal Science Journal
Show more