Fatty acid regio-specificity of triacylglycerol molecules may affect plasma lipid responses to dietary fats-a randomised controlled cross-over trial

The Impact of Diet on Lipoprotein(a) Levels

BACKGROUND

Lipoprotein(a) [Lp(a)] is recognized as an independent risk factor for cardiovascular diseases; however, the impact of fat-based diets on its levels remains unclear.

OBJECTIVE

This study aims to assess and analyze current evidence on the impact of various types of fat-based diets on Lp(a) levels.

MATERIAL AND METHODS

A comprehensive search of the PubMed database was conducted on 9 July 2024, focusing on clinical and randomized trials published since 2000. Out of 697 identified studies, 33 met the inclusion criteria and were selected for analysis.

RESULTS

The findings suggest that modifications in fat-based diets, particularly concerning the type and amount of consumed fats and fatty acids, can significantly influence plasma Lp(a) levels. Diets rich in unsaturated fats, including polyunsaturated and monounsaturated fatty acids, were associated with more favorable effects in lowering Lp(a) levels. In contrast, diets high in saturated fats were linked to elevated Lp(a) levels. However, these conclusions were not consistent across all studies considered.

CONCLUSIONS

This work highlights the importance of a personalized dietary approach, considering both genetic predispositions and dietary habits. While diet alone may not drastically alter Lp(a) levels due to their strong genetic determination, a comprehensive strategy involving a healthy diet rich in unsaturated fats, regular physical activity, and effective weight management is recommended to reduce the risk of cardiovascular diseases. Further research is needed to clarify the mechanisms through which different fats affect Lp(a) and to develop targeted dietary recommendations.

Effect of Extra Virgin Olive Oil on Anthropometric Indices, Inflammatory and Cardiometabolic Markers: a Systematic Review and Meta-Analysis of Randomized Clinical Trials

BACKGROUND

A large body of literature associated extra virgin olive oil (EVOO) consumption with low risk of cardiovascular disease and mortality. However, findings from clinical trials related to EVOO consumption on blood pressure, lipid profile, and anthropometric and inflammation parameters are not univocal.

OBJECTIVES

The aim of this systematic review and meta-analysis was to evaluate the effect of EVOO consumption on cardiometabolic risk factors and inflammatory mediators.

METHODS

We searched PubMed/MEDLINE, Scopus, and Cochrane up through 31 March, 2023, without any particular language limitations, in order to identify randomized controlled trials (RCTs) that examined the effects of EVOO consumption on cardiometabolic risk factors, inflammatory mediators, and anthropometric indices. Outcomes were summarized as standardized mean difference (SMD) with 95% confidence intervals (CIs) estimated from Hedge's g and random-effects modeling. Heterogeneity was assessed by Cochran Q-statistic and quantified (I2).

RESULTS

Thirty-three trials involving 2020 participants were included. EVOO consumption was associated with a significant decrease in insulin (n = 10; SMD: -0.28; 95% CI: -0.51, -0.05; I2 = 48.57%) and homeostasis model assessment of insulin resistance levels (HOMA-IR) (n = 9; SMD: -0.19; 95% CI: -0.35, -0.03; I2 = 00.00%). This meta-analysis indicated no significant effect of consuming EVOO on fasting blood glucose, triglycerides, total cholesterol, low density lipoproteins, very low density lipoproteins, high density lipoproteins, Apolipoprotein (Apo) A-I and B, lipoprotein a, blood pressure, body mass index, waist circumference, waist to hip ratio, C-reactive protein, interleukin-6, interleukin-10, and tumor necrosis factor α levels (P > 0.05).

CONCLUSIONS

The present evidence supports a beneficial effect of EVOO consumption on serum insulin levels and HOMA-IR. However, larger well-designed RCTs are still required to evaluate the effect of EVOO on cardiometabolic risk biomarkers. This study was registered in PROSPERO as CRD42023409125.

The effects of olive oil consumption on blood lipids: a systematic review and dose-response meta-analysis of randomised controlled trials

We performed a systematic review and dose-response meta-analysis of randomised trials on the effects of olive oil consumption on blood lipids in adults. A systematic search was performed in PubMed, Scopus and Web of Science databases until May 2021. Randomised controlled trials (RCT) evaluating the effect of olive oil intake on serum total cholesterol (TC), TAG, LDL-cholesterol and HDL-cholesterol in adults were included. The mean difference (MD) and 95 % CI were calculated for each 10 g/d increment in olive oil intake using a random-effects model. A total of thirty-four RCT with 1730 participants were included. Each 10 g/d increase in olive oil consumption had minimal effects on blood lipids including TC (MD: 0·79 mg/dl; 95 % CI (-0·08, 1·66); I² = 57 %; n 31, GRADE = low certainty), LDL-cholesterol (MD: 0·04 mg/dl, 95 % CI (-1·01, 0·94); I² = 80 %; n 31, GRADE = very low certainty), HDL-cholesterol (MD: 0·22 mg/dl; 95 % CI (-0·01, 0·45); I² = 38 %; n 33, GRADE = low certainty) and TAG (MD: 0·39 mg/dl; 95 % CI (-0·33, 1·11); I² = 7 %; n 32, GRADE = low certainty). Levels of TC increased slightly with the increase in olive oil consumption up to 30 g/d (MD_{30 g/d}: 2·76 mg/dl, 95 % CI (0·01, 5·51)) and then appeared to plateau with a slight downward curve. A trivial non-linear dose-dependent increment was seen for HDL-cholesterol, with the greatest increment at 20 g/d (MD_{20 g/d}: 1·03 mg/dl, 95 % CI (-1·23, 3·29)). Based on existing evidence, olive oil consumption had trivial effects on levels of serum lipids in adults. More large-scale randomized trials are needed to present more reliable results.

Impact of Extensively Hydrolyzed Infant Formula on Circulating Lipids During Early Life

Background

Current evidence suggests that the composition of infant formula (IF) affects the gut microbiome, intestinal function, and immune responses during infancy. However, the impact of IF on circulating lipid profiles in infants is still poorly understood. The objectives of this study were to (1) investigate how extensively hydrolyzed IF impacts serum lipidome compared to conventional formula and (2) to associate changes in circulatory lipids with gastrointestinal biomarkers including intestinal permeability.

Methods

In a randomized, double-blind controlled nutritional intervention study (n = 73), we applied mass spectrometry-based lipidomics to analyze serum lipids in infants who were fed extensively hydrolyzed formula (HF) or conventional, regular formula (RF). Serum samples were collected at 3, 9, and 12 months of age. Child's growth (weight and length) and intestinal functional markers, including lactulose mannitol (LM) ratio, fecal calprotectin, and fecal beta-defensin, were also measured at given time points. At 3 months of age, stool samples were analyzed by shotgun metagenomics.

Results

Concentrations of sphingomyelins were higher in the HF group as compared to the RF group. Triacylglycerols (TGs) containing saturated and monounsaturated fatty acyl chains were found in higher levels in the HF group at 3 months, but downregulated at 9 and 12 months of age. LM ratio was lower in the HF group at 9 months of age. In the RF group, the LM ratio was positively associated with ether-linked lipids. Such an association was, however, not observed in the HF group.

Conclusion

Our study suggests that HF intervention changes the circulating lipidome, including those lipids previously found to be associated with progression to islet autoimmunity or overt T1D.

Clinical Trial Registration

[Clinicaltrials.gov], identifier [NCT01735123].

Chicken Oil as The New Cooking Oil : Its Effect on Lipid Profile and Liver Histology in Male Wistar Rats

 ABSTRACTBackground: The selection of the appropriate cooking oil by society will reduce high fat intake. Chicken oil as a new cooking oil that is starting to be used by some people as a substitute for palm oil, needs to be studied for its health effects.Objectives: This study aimed to see and compare changes in lipid profiles and liver histology in male Wistar rats fed with chicken oil and palm oil.Methods: Male Wistar rats (n = 10) were separated into two groups randomly, namely the chicken oil group and the palm oil group.  Each rat in the group was given oil at a dose of 1 mL/day. Before treatment, lipid profile levels were measured, and after four weeks of treatment, lipid profile levels and liver histology were examined.Results: Administration of 1 mL/day of oil in each group for four weeks diminished total cholesterol, HDL, LDL levels at the two groups also increased triglyceride levels in the two groups, but non-significant differences among groups. This research also showed the formation of hepatic steatosis in all groups, but still mild-moderate microvesicular steatosis, and non-significant differences among groups.Conclusion: The consumption of 1 mL/day of chicken oil for four weeks has a similar effect on lipid profiles and liver histology as the consumption of 1 mL/day of palm oil with the same duration. We propose further study by administering the intervention of chicken oil to rats for a longer time.

Eucaloric diets enriched in palm olein, cocoa butter, and soybean oil did not differentially affect liver fat concentration in healthy participants: a 16-week randomized controlled trial

BACKGROUND

Effects of dietary fat quality on liver fat remain to be elucidated. Inconsistent evidence may be influenced by fatty acid saturation, chain-length, and regio-specificity within triacylglycerol (TAG) molecules.

OBJECTIVES

We aimed to compare eucaloric diets enriched in palm olein (POo), cocoa butter (COB), and soybean oil (SBO) on liver fat concentration in healthy participants. Secondary outcomes included visceral (VAT) and abdominal subcutaneous (aSCAT) adipose tissue, plus other obesity and cardiometabolic health outcomes.

METHODS

Eighty-three healthy participants (20-45 y, BMI 18.5-27.5 kg/m2) commenced and 64 completed a 16-wk randomized parallel intervention, preceded by a 2-wk run-in. Participants consumed identical eucaloric background diets differing in test fats [contributing 20% total energy intake (%E)], providing 33%E total fat with the following ratios for PUFAs/SFAs/MUFAs: POo, 4.2/13.5/15%E; SBO, 14.4/8.8/9.4%E; COB, 2.3/19.5/11%E. Liver fat and abdominal adiposity were measured at weeks 0 and 16 using 1H-magnetic resonance spectroscopy/imaging; all other outcomes were measured at 0, 4, 8, 12, and 16 wk.

RESULTS

Fat quality did not affect liver fat concentration, VAT, aSCAT, obesity indexes, blood pressure, liver enzymes, leptin, or fasting glucose. Body fat mass decreased with SBO and COB compared with POo. SBO decreased serum total cholesterol (TC), LDL cholesterol, and TC:HDL cholesterol relative to POo [estimated marginal mean (95% CI) differences: -0.57 (-0.94, -0.20) mmol/L; -0.37 (-0.68, -0.07) mmol/L; and -0.42 (-0.73, -0.11) mmol/L, respectively]. No diet differences were observed on HDL cholesterol, TAG, apoA1, apoB, apoB:apoA1, or fecal free fatty acids (FFAs), except for lower FFA pentadecanoic acid (15:0) with COB than with SBO and POo.

CONCLUSIONS

In healthy adults, when consumed as part of eucaloric typical Australian diets, 3 different dietary fat sources did not differentially affect liver fat concentration and amounts of adipose tissue. Effects on serum lipids were inconsistent across lipid profiles. The findings must be confirmed in metabolically impaired individuals before recommendations can be made.