Plasma n-3 polyunsaturated fatty status and its relationship with vitamin E intake and plasma level

Lifestyle Factors Associated with Circulating Very Long-Chain Saturated Fatty Acids in Humans: A Systematic Review of Observational Studies

Recent observational studies have documented inverse associations of circulating very long-chain saturated fatty acids (VLCSFAs), namely arachidic acid (20:0), behenic acid (22:0), and lignoceric acid (24:0), with cardiometabolic outcomes. In addition to their endogenous production, it has been suggested that dietary intake or an overall healthier lifestyle may influence VLCSFA concentrations; however, a systematic review of the modifiable lifestyle contributors to circulating VLCSFAs is lacking. Therefore, this review aimed to systematically assess the effects of diet, physical activity, and smoking on circulating VLCSFAs. Following registration on PROSPERO (International Prospective Register of Systematic Reviews) (ID: CRD42021233550), a systematic search of observational studies was conducted in MEDLINE, EMBASE, and The Cochrane databases up to February 2022. A total of 12 studies consisting of mostly cross-sectional analyses were included in this review. The majority of the studies documented the associations of dietary intake with total plasma or red blood cell VLCSFAs, in which a range of macronutrients and food groups were examined. Two cross-sectional analyses showed a consistent positive association between total fat and peanut intake with 22:0 and 24:0 and an inverse association between alcohol intake and 20:0 and 22:0. Furthermore, a moderate positive association between physical activity and 22:0 and 24:0 was observed. Lastly, there were conflicting results on the effects of smoking on VLCSFA. Although most studies had a low risk of bias; the findings of this review are limited by the bi-variate analyses presented in the majority of the included studies, therefore, the impact of confounding is unclear. In conclusion, although the current observational literature examining lifestyle determinants of VLCSFAs is limited, existing evidence suggests that circulating 22:0 and 24:0 may be influenced by higher total and saturated fat consumption and nut intake.

Potential Therapeutic Properties of the Leaf of Cydonia Oblonga Mill. Based on Mineral and Organic Profiles

Leaf extract of Cydonia Oblonga Mill. is interesting for further exploration of the potential of its substrates for therapeutic supplements. Quantitative and qualitative analyses were conducted on samples of green (October), yellow (November), and brown (December) quince leaves collected in the region of Pinhel, Portugal. Mineral analysis determined the measurements of the levels of several macro- and micro-elements. Organic analysis assessed the moisture content, total phenolic content (TPC), vitamin E, and fatty acid (FA) profiles. Mineral analysis was based on ICP-MS techniques, while the profiles of vitamin E and FA relied on HPLC-DAD-FLD and GC-FID techniques, respectively. Moisture content was determined through infrared hygrometry and TPC was determined by spectrophotometric methods. Regarding the mineral content, calcium, magnesium, and iron were the most abundant minerals. Concerning organic analysis, all leaf samples showed similar moisture content, while the TPC of gallic acid equivalents (GAE) and total vitamin E content, the most predominant of which was the α-tocopherol isomer, showed significant variations between green-brown and yellow leaves. FA composition in all leaf samples exhibited higher contents of SFA and PUFA than MUFA, with a predominance of palmitic and linolenic acids. Organic and inorganic analysis of quince leaves allow for the prediction of adequate physiological properties, mainly cardiovascular, pulmonary, and immunological defenses, which with our preliminary in silico studies suggest an excellent supplement to complementary therapy, including drastic pandemic situations.

Pre-analytical monitoring and protection of oxidizable lipids in human plasma (vitamin E and ω-3 and ω-6 fatty acids): An update for redox-lipidomics methods

Sample manipulation for storage and storage itself, interfere with the stability of labile lipids in human plasma, including vitamin E (α-tocopherol), polyunsaturated fatty acids (PUFAs), and their enzymatic and free radical-derived oxidation metabolites. This remains a main limit of lipidomics studies that often lack of sufficient standardization and validation at the pre-analytical level. In order to characterize the stability of these lipids in human plasma and to develop a standardized pre-analytical protocol for lipidomics methods, the oxidation metabolites of α-tocopherol, the free form of ω3 and ω6 PUFAs, and some arachidonic acid (AA)-derived eicosanoids were investigated in human plasma during storage at different freezing temperatures. The effect of a protection/defense cocktail of antioxidants and lipoxygenase inhibitors (PD solution) on these lipid parameters was also evaluated. The temperature of storage markedly affected the formation of α-tocopheryl quinone (α-TQ), the main lipoperoxyl radical-derived oxidation metabolite of vitamin E, with the lowest production rate observed in samples stored at -80 °C or in liquid nitrogen. A similar effect of the storage temperature was observed for the free form of the ω-3 species eicosapentaenoic and docosahexaenoic acid, and for the ω-6 AA. Freezing samples at -20 °C resulted in a time-dependent formation of the pro-inflammatory eicosanoid LTB4. The PD solution prevents non-specific alterations of these lipid parameters in samples that are processed for direct analysis and protects from the temperature-dependent modifications of free PUFAs. Combining PD solution and preservation at -80 °C or in liquid nitrogen, resulted in levels of α-TQ and PUFAs that remained stable over 1 month and up to 8 months of storage, respectively. This method paper provides indications for the optimal processing and storage of human plasma utilized in lipidomics studies.

Study of Cardiovascular Risk Factors in Adolescents: Association between Intake of Vitamins A and E and Lipid Profile

Background:

The diet of Brazilian adolescents is characterized by high intake of fats and sugars and low consumption of antioxidant micronutrients, particularly vitamins A and E. In addition to dietary inadequacies, a significant number of these adolescents present changes in plasma lipoproteins, which may be caused by environmental and lifestyle factors.

Objective:

To investigate the association between inadequate intake of vitamins A and E and changes in plasma lipoprotein concentrations in Brazilian adolescents.

Methods:

Cross-sectional, descriptive, multicenter, school-based, nationwide study with 37,023 Brazilian adolescents aged 12 to 17 years were included. Data on sociodemographic characteristics, vitamin A and E intake, and lipid and anthropometric profile were collected. The Student’s t-test was used to compare means and a logistic regression to verify associations; analyses were conducted in the STATA software version 14.0. The study was approved by the Ethics Committees of the participating institutions and all participants signed an Assent Form.

Results:

The average vitamin A intake was higher among boys, but consumption below recommendation was found in both sexes. Inadequate intake of vitamins A and E was associated with a higher risk of low HDL-c levels in male and public school adolescents. Low vitamin E intake was associated with a higher risk of hypercholesterolemia and hypertriglyceridemia in Brazilian adolescents.

Conclusion:

This study showed a high prevalence of inadequate intake of vitamins A and E among Brazilian adolescents and data suggesting associations between low intake of these micronutrients and changes in plasma lipoprotein concentrations in this public.