BACKGROUND: TRANS-fatty acids (TFAs), unsaturated FATS with at least one double bond in the TRANS configuration, are industrially formed in large quantities when vegetable oils are partially hydrogenated. This study was undertaken to quantify the amounts of the common fatty acids in several commercial oils marketing in Iran.METHODS: The most consumed commercially available brands of vegetable oils were randomly selected from products available in supermarkets. A 10g sample was drawn from each mixed sample and prepared for fatty acid analysis by gas chromatography (GC).RESULTS: Palmitic acid (C16:0) and stearic acid (C18:0) jointly constituted 21% of total fatty acids in partially hydrogenated vegetable oils (PHVOs). More than one third of total fatty acids in Iranian PHVOs were TRANS FATS. TFAs constituted almost 1% and 3% of total fatty acids in Iranian cooking and frying oils. This study showed higher contents of TFAs in Iranian commercially available hydrogenated vegetable oils. Statistical Package for Social Sciences was used for all statistical analyses.CONCLUSIONS: Although several studies reported multiple adverse effects of TFAs on human health, limited information is available about total fatty acid composition, particularly TFAs, in Iranian edible oils. Our findings indicated higher content of TFAs in Iranian commercially available PHVOs.

Background: Colorectal cancer (CRC) is the 3rd or 4th most common cancer with the marked increasing incidence and mortality rates in most countries in the last few decades.Lifetime risk of developing CRC is 1 in 20 (5%). The present study aimed to see effects of different types of FATS on carcinogenesis by review of the randomized controlled trials (RCTs) published in the past 10 years.Results: CRC has long and multifactorial Pathogenesis process from mutations in specific oncogenes and tumor suppressor genes to alterations in gene expression by Epigenetic or Non genotoxic mechanism, however environmental factors and lifestyle, makes the most difference in cancer risk between people, High-fat diets are generally associated with high risk of colon cancer, in this issue types of fat and effects on carcinogenesis are different.Some Mechanisms dietary FATS increase colon carcinogenesis are as follows: 1) high-fat diet activates oncogenic cascades, involve Epithelial-mesenchymal TRANSition and inflammation in CRC, and play important roles in tumor growth and progression 2) repeated exposure to secreted bile acids, associated with a high-fat diet, activates formation of reactive oxygen and nitrogen species that cause DNA damage and increase in mutant cells with growth advantage 3) Accumulation of hyper oxidizable triglycerides in cytoplasm of intestinal epithelial cells induce DNA damage link to truncation mutation in both alleles of the Apc gene 4) High fat diets induce obesity hormones by which signaling via receptors and activated pathways (mTOR) is the other mechanism called obesity related colon cancer.Experimental studies showed high-fat diet rich in n-6 polyunsaturated fatty acid (PUFA) and saturated fatty acids (SFA) promoted colon carcinogenesis, diets rich in n-3 PUFA and n-9 monounsaturated FA (MUFA) reduced colon tumorigenesis. Epidemiological and observational reports showed that n-3 PUFA-rich diet may suppressed the risk of colon cancer in humans. Milk as a Dairy product, had an inverse association whit CRC, TFA intake was associated with increased CRC risk, and Interestingly natural (dairy) TFAs with high calcium content have less unfavorable metabolic effects.Conclousion: amount of fat intake and composition of dietary FA are crucial factors for colon carcinogenesis, which gives opportunity for effective prevention and intervention.