trans Fatty acid consumption, lifestyle and type 2 diabetes prevalence in a Spanish population

Thermally induced isomerization of linoleic acid and α-linolenic acid in Rosa roxburghii Tratt seed oil

Rosa roxburghii seed oil is obtained from the seeds left following pressing of the juice from R. roxburghii fruit. The total oil content of R. roxburghii seed was around 9.30%. The fatty acid profile of the oil was determined by gas chromatography (GC). Among the 11 fatty acids identified in the oil, seven were unsaturated fatty acids (UFAs) (92.6%); four were saturated fatty acids (SFAs) (7.17%). Then, the kinetics of formation of trans-fatty acids was studied by GC. Heat treatment of R. roxburghii seed oil showed an increase in the relative percentage of linoleic acid and α-linolenic acid isomers with increasing temperature and time. The formation of linoleic acid and α-linolenic acid isomers followed a zero-order reaction. The presence of O2 enhanced the isomerization of these UFAs. In addition, the rate constants and activation energies for the geometrical isomerization of UFAs in R. roxburghii seed oil were presented. Overall, R. roxburghii seed oil contains high UFA contents. Heating temperature and duration and the presence of O2 should be considered to reduce the formation of trans-fatty acids during thermal treatment of R. roxburghii seed oil.

Trans fatty acid intake among Chinese population: a longitudinal study from 1991 to 2011

Objective

This study was aimed to roughly describe individual Trans Fatty Acids (TFAs) intake and the percentage of energy intake(E%), and identify major food sources in the Chinese population, taking gender, age, and regional distribution into the consideration, as well as examining temporal changes over the course of 20 years.

Method

This multi-center study, covering nine provinces among populations aged ≥ 3 in China, was conducted to collect food consumption information from 1991 to 2011. A classical assessment method was used to estimate the level of dietary TFA intake.

Results

Over the 20-year period, the intake of TFAs in Chinese populations had increased, but remained at a relatively lower level (from 0.25 g/d(0.11% for E%) to 0.53 g/d(0.24% for E%)) compared with that of other countries and the World Health Organization (WHO) recommended level. Collectively, males and participants aged 19–60 generally consumed more TFA-containing foods. People in eastern regions consumed more TFAs and had a higher E% than those in western area. Industrial sources of TFAs, especially vegetable oil, ranked as the principal food sources of TFAs in the Chinese population. Natural sources of TFAs have gradually increased in proportion among children and adolescents.

Conclusions

TFA intake and the E% are commonly under the recommended level in the general population in China. Presently, restriction of vegetable oil could be a crucial method to reduce TFA intake. It would be critical to facilitate and promote public health that food recommendations might be based on the dietary preferences for population separated by different ages and regions.

Some biochemical studies on trans fatty acid-containing diet

trans fatty acids (TFA's) are unsaturated fatty acid which have one or more double bond, they are present naturally and most of it is artificial, fried, baked food and margarine are major sources of TFA, there are several biological effects of TFAs on body health, various study showed that dietary TFA associated with various health disorders such as Diabetes, cardiovascular disease (CVD), Obesity, breast cancer, prostatic cancer infertility, and coronary artery disease (CAD). The World Health Organization (WHO) in 2015 encourages eliminations of trans fatty acids. The diet which related to non-communicable diseases include TFA should be eliminated, WHO's European Food and Nutrition Action Plan 2015-2020 suggested that TFAs should be less than 1% of the daily energy intake include natural origin. So the aim of this review, to know more than about trans acids, their nature, sources, and their different effect on health and how can analysis it.

Association between plasma trans-fatty acid concentrations and diabetes in a nationally representative sample of US adults

BACKGROUND

A diet high in trans-fatty acids (TFA) induces insulin resistance in rodent models and primates. However, previous epidemiological studies on the association between TFAs, based primarily on self-reported intake from the diet, and diabetes in humans have yielded conflicting results. Herein we examined the associations of objectively measured plasma TFA concentrations with diabetes in a large population-based study among US adults.

METHODS

We included 3801 participants aged ≥20 years from the National Health and Nutrition Examination Survey 1999-2000 and 2009-10. Four major TFAs, namely palmitelaidic acid (C16:1 n-7t), elaidic acid (C18:1 n-9t), vaccenic acid (C18:1 n-7t), and linolelaidic acid (C18:2 n-6t, 9t), were measured in fasting plasma using gas chromatography-mass spectrometry. Diabetes was defined by self-reported physician diagnosis, plasma fasting glucose ≥126 mg/dL, or HbA1c ≥6.5%.

RESULTS

After adjustment for other major risk factors, the odds ratios (95% confidence intervals) of diabetes comparing the highest with lowest quintile of plasma TFAs was 2.19 (1.27-3.79) for total TFAs (P_trend  = 0.01), 2.34 (1.48-3.72) for elaidic acid (P_trend  = 0.0004), 1.33 (0.82-2.15) for linolelaidic acid (P_trend  = 0.18), 1.58 (0.97-2.58) for palmitelaidic acid (P_trend  = 0.02), and 1.64 (0.95-2.84) for vaccenic acid (P_trend  = 0.08). In addition, total TFAs, elaidic acid, palmitelaidic acid, and vaccenic acid were significantly associated with fasting glucose, fasting insulin, the insulin resistance index, and HbA1c.

CONCLUSIONS

In a nationally representative population, plasma TFAs, in particular elaidic acid, were positively associated with diabetes and biomarkers of glucose metabolism.

Research advances based on mass spectrometry for profiling of triacylglycerols in oils and fats and their applications

Vegetable oils and animal fats are dietary source of lipids that play critical and multiple roles in biological function. Triacylglycerols (TAGs) are the principal component of oils and fats with significant difference in profile among different oils and fats. TAG profiling is essential for nutritional evaluation, quality control and assurance of safety in oils and fats. However, analysis of TAGs is a challenging task because of the complicated composition of TAGs and their similar physicochemical properties in oils and fats. The rapid development of mass spectrometry (MS) technology in recent years makes it possible to analyze the composition, content and structure of TAGs in the study of the physical, chemical and nutritional properties of oils, fats and related products. This review described the research advancement based on MS for profiling of TAGs in oil, fat and their applications in food. The application of MS, including direct infusion strategies, and its combination with chromatography, gas chromatography-MS (GC-MS) and liquid chromatography-MS (LC-MS), in the analysis of TAGs were reviewed. The advantages and disadvantages of these analytical methods with relevant applications for TAGs analysis in food were also described.

Effect of traditional Chinese cooking methods on fatty acid profiles of vegetable oils

The effect of four frying processes (vegetable salad, stir frying, pan frying, and deep frying) on fatty acid composition of ten vegetable oils (peanut oil, soybean oil, rapeseed oil, corn oil, sunflower seed oil, rice bran oil, olive oil, sesame oil, linseed oil, and peony seed oil) was investigated using GC-MS. The result showed that trans-fatty acid (TFA) was produced during all processes. Rapeseed oil had the highest TFA content in vegetable salad oil with 2.88% of total fatty acid. The TFA content of sunflower seed oil was 0.00% in vegetable salad oil, however, after stir frying and pan frying, it increased to 1.53% and 1.29%, respectively. Peanut oil had the lowest TFA content after deep frying for 12h with 0.74mg/g. It was concluded that a healthy cooking process could be acquired by a scientific collocation.

Effects of trans fatty acids on glucose homeostasis: a meta-analysis of randomized, placebo-controlled clinical trials

BACKGROUND

Although evidence from cohort studies has suggested that trans fatty acid (TFA) consumption may be associated with insulin resistance and diabetes, randomized placebo-controlled trials (RCTs) have yielded conflicting results.

OBJECTIVE

In a meta-analysis, we combined all available RCTs that examined the role of TFA intake on glucose homeostasis.

DESIGN

A systematic review of PubMed was performed, and a total of 7 RCTs were included in the meta-analysis. Primary outcomes were glucose and insulin concentrations. Secondary outcomes were total, LDL-, and HDL-cholesterol and triglyceride concentrations. The pooled effect size (ES) was calculated through fixed- and random-effects meta-analyses. The potential existence of publication bias was evaluated by using funnel-plot analysis. Metaregression analysis was performed to evaluate for potential dose-response relations between the ES of outcomes and TFA intake.

RESULTS

Increased TFA intake did not result in significant changes in glucose or insulin concentrations. Increased TFA intake led to a significant increase in total and LDL-cholesterol [ES (95% CI): 0.28 (0.04, 0.51) and 0.36 (0.13, 0.60), respectively] and a significant decrease in HDL-cholesterol concentrations [ES (95% CI): -0.25 (-0.48, -0.01)]. Our analysis also showed the absence of publication bias and any dose-response relations between the ES and TFA intake.

CONCLUSIONS

Increased TFA intake does not result in changes in glucose, insulin, or triglyceride concentrations but leads to an increase in total and LDL-cholesterol and a decrease in HDL-cholesterol concentrations. There is no evidence to support a potential benefit of the reduction of dietary TFA intake on glucose homeostasis.