The association between dietary fats and the incidence risk of cardiovascular outcomes: Tehran Lipid and Glucose Study

John Yudkin's hypothesis: sugar is a major dietary culprit in the development of cardiovascular disease

To date, the risk of developing atherosclerosis has extended beyond Western countries and now affecting individuals from various ethnic backgrounds and age groups. Traditional risk factors of atherosclerosis, such as hypercholesterolemia, has been better controlled than before due to highly effective and inexpensive therapies at lowering plasma cholesterol levels. However, the role of reducing dietary cholesterol intake, as a public healthy strategy, in preventing the occurrence of cardiovascular mortalities has been recently challenged. Indeed, despite our continuous decline of dietary cholesterol intake within the last 50 years, the incidence of cardiovascular mortalities has continued to rise, thus raising the possibility that other dietary factors, such as fructose-containing sugars, are the major culprit. In the 1970s, John Yudkin first proposed that sugar was the predominant dietary factor that underlies the majority of cardiovascular mortalities, yet his hypothesis was dismissed. However, over the last 25 years substantial scientific evidence has been accumulated to support Yudkin's hypothesis. The objectives of this review are to highlight Yudkin's significant contribution to nutritional science by reviewing his hypothesis and summarizing the recent advances in our understanding of fructose metabolism. The metabolic consequences of fructose metabolism, such as fructose-induced uricemia, insulin resistance, lipoprotein hyperproduction and chronic inflammation, and how they are linked to atherosclerosis as risk factors will be discussed. Finally, the review will explore areas that warrant future research and raise important considerations that we need to evaluate when designing future studies.

Modulatory effects of dietary saturated fatty acids on platelet mitochondrial function following short-term exposure to ambient Particulate Matter (PM2.5)

Exposure to ambient fine particulate matter (PM2.5) was found to produce vascular injury, possibly by activating platelets within days after exposure. The aim of this study was to investigate the modulatory effects of dietary saturated fatty acids on platelet mitochondrial respiratory parameters following short-term inhalational exposure to PM2.5. A total of 22 healthy male volunteers were recruited from the Research Triangle area of North Carolina. Platelets were isolated from fresh whole blood samples and mitochondrial respiratory parameters were measured using an extracellular flux analyzer. Intake of saturated fat was averaged from multiple 24-hr dietary recalls. Daily ambient PM2.5 concentrations were obtained from ambient air quality monitoring stations. Correlation and ANOVA were used in data analyses, along with the pick-a-point method and the Johnson-Neyman technique for probing moderation. After controlling for age and omega-3 index, the intake of dietary saturated fatty acids after reaching 9.3% or higher of the total caloric intake significantly moderated the associations between PM2.5 exposure and several platelet mitochondrial respiratory parameters. In conclusion, dietary saturated fatty acids above 9.3% of total caloric intake influenced the relationship between short-term PM2.5 exposure and platelet mitochondrial respiration. Further research is needed to understand these associations and their implications for cardiovascular health.

Dietary fat types consumption association with obesity and coronary indices

This article aims to study the different dietary fat types associated with obesity and coronary indices. A sample of 491 healthy adults was included in a cross-sectional manner. Dietary fats intake, obesity indices (conicity index (CI), body adiposity index (BAI), abdominal volume index (AVI), body roundness index (BRI), and weight-adjusted-waist index (WWI)), and cardiovascular indices (cardiometabolic index (CMI), lipid accumulation product (LAP), and atherogenic index of plasma (AIP)) were calculated and studied. Participants with an acceptable intake of omega-3 had a higher BRI score (1⋅90 ± 0⋅06 v. 1⋅70 ± 0⋅06). Participants with an unacceptable intake of cholesterol had a higher CI (1⋅31 ± 0⋅11 v. 1⋅28 ± 0⋅12; P = 0⋅011), AVI (20⋅24 ± 5⋅8 v. 18⋅33 ± 6⋅0; P < 0⋅001), BRI (2⋅00 ± 1⋅01 v. 1⋅70 ± 1⋅00; P = 0⋅003), WWI (11⋅00 ± 0⋅91 v. 10⋅80 ± 0⋅97; P = 0⋅032), and lower AIP (0⋅46 ± 0⋅33 v. 0⋅53 ± 0⋅33; P = 0⋅024). Total fat, saturated fat (SFA), and polyunsaturated fat (PUFA) intake had a significant moderate correlation with AVI and BRI. The monounsaturated fat (MUFA) intake had a significantly weak correlation with CI, AVI, BRI, WWI, and AIP. Cholesterol and omega-6 had weak correlations with all indices. Similar correlations were seen among male and female participants. The different types of fat intake significantly affected obesity and coronary indices, especially SFA and PUFA, as well as omega-3 and cholesterol. Gender and the dietary type of fat intake have a relationship to influence the indicators of both obesity and coronary indices.

Plasma fatty acid composition and some markers of dietary habits are associated with cardiovascular disease risk determined by an atherogenic plasma index in postmenopausal women

It is hypothesized that plasma proportion of selected fatty acids (FAs) and dietary habits are linked with the risk of cardiovascular disease (CVD) in postmenopausal women. Therefore, this study was designed to determine the association of plasma FA composition and markers of dietary habits with an atherogenic index of plasma (AIP), a predictor of CVD risk in postmenopausal women. In total, 87 postmenopausal women with an average age of 57 ± 7 years were recruited and their dietary intake, anthropometric and biochemical parameters, and FA status in total plasma lipid proportions were determined, showing that 65.5% of the participants had a high risk of CVD according to their AIP value. After adjusting for some confounders (age, body mass index, and physical activity level), the risk of CVD was only positively associated with the frequency of consumption of animal fat spreads (butter and lard) of terrestrial origin. Regarding the FA profile, CVD risk was positively associated with the percentages of vaccenic acid, dihomo-γ-linolenic acid, and monounsaturated fatty acids (MUFA; mainly n-7) in total FA, as well as the MUFA/SFA ratio in total plasma and stearoyl-CoA desaturase-16 activity (16:1/16:0 ratio). In contrast, the risk of CVD was negatively associated with percentages of α-linolenic acid, total polyunsaturated fatty acids (PUFA), and PUFA/MUFA ratio in total plasma lipid, and the estimated activity of Δ5-desaturase (20:4/20:3 n-6 ratio). These results support the current recommendations to decrease the frequency of animal fat spread intake because it is associated with a reduced CVD risk based on AIP in postmenopausal women. In accordance with these plasma percentages of ALA, vaccenic acid, dihomo-γ-linolenic acid, PUFA, PUFA/MUFA ratio, and 16:1/16:0 ratio may be important parameters in CVD risk assessment.

Role of food matrix in modulating dairy fat induced changes in lipoprotein particle size distribution in a human intervention

BACKGROUND

Intake of dairy fat within the matrix of cheese lowered circulating LDL cholesterol concentration to a greater extent than the same components consumed separately as butter, protein, and calcium. However, circulating LDL cholesterol is not indicative of concentration or size of LDL particles (LDL-P), which are recognized as more sensitive risk markers of CVD.

OBJECTIVES

This was an exploratory analysis to investigate the role of the food matrix on lipoprotein particle size distribution, after a dairy fat intervention, in overweight adults aged ≥50 y.

METHODS

Lipoprotein particle size distribution was measured in fasting EDTA blood samples taken at week 0 (baseline) and at week 6, using NMR. In total, 127 participants (BMI ≥ 25 kg/m², aged ≥50 y) received ∼42 g dairy fat in 1 of 4 treatments: group A, 120 g full-fat cheddar cheese (FFCC); group B, reduced-fat cheese plus butter (RFC+B); group C, butter, calcium caseinate powder, and calcium supplement (CaCO₃) (BCC); or group D, 120 g FFCC (as per group A) but after a 6-wk washout period during which they excluded cheese before intervention.

RESULTS

Total VLDL and chylomicron particles (VLDL/CM-P) decreased after intervention. There was a strong correlation between reduced VLDL/CM-P and a reduction in small proatherogenic VLDL-P (r = 0.888, P < 0.001). Reductions in total LDL-P were associated with a reduction in small LDL-P and, to a lesser extent, with large LDL-P. There was a significant main effect of treatment for change in intermediate-density lipoprotein particles (IDL-P) after the intervention (P = 0.023) between groups B and D (-46.86 ± 30.38 and 40.69 ± 32.72 nmol/L, respectively). HDL particle (HDL-P) parameters (diameter, concentration, or size distribution) were not affected by diet.

CONCLUSIONS

Our findings indicate that reductions in LDL cholesterol observed with dairy fat consumption are driven by reductions in LDL-P concentration. A trend toward a less atherogenic profile was observed, but there was no clear effect of the individual food matrices. This trial was registered at ISRCTN as ISRCTN86731958.

Serum Metabolomic Profiling in Aging Mice Using Liquid Chromatography-Mass Spectrometry

BACKGROUND

The process of aging and metabolism are intricately linked, thus rendering the identification of reliable biomarkers related to metabolism crucial for delaying the aging process. However, research of reliable markers that reflect aging profiles based on machine learning is scarce.

METHODS

Serum samples were obtained from aged mice (18-month-old) and young mice (3-month-old). LC-MS was used to perform a comprehensive analysis of the serum metabolome and machine learning was used to screen potential aging-related biomarkers.

RESULTS

In total, aging mice were characterized by 54 different metabolites when compared to control mice with criteria: VIP ≥ 1, q-value < 0.05, and Fold-Change ≥ 1.2 or ≤0.83. These metabolites were mostly involved in fatty acid biosynthesis, cysteine and methionine metabolism, D-glutamine and D-glutamate metabolism, and the citrate cycle (TCA cycle). We merged the comprehensive analysis and four algorithms (LR, GNB, SVM, and RF) to screen aging-related biomarkers, leading to the recognition of oleic acid. In addition, five metabolites were identified as novel aging-related indicators, including oleic acid, citric acid, D-glutamine, trypophol, and L-methionine.

CONCLUSIONS

Changes in the metabolism of fatty acids and conjugates, organic acids, and amino acids were identified as metabolic dysregulation related to aging. This study revealed the metabolic profile of aging and provided insights into novel potential therapeutic targets for delaying the effects of aging.

Long Term Dietary Supplementation with Omega-3 Fatty Acids in Charolais Beef Cattle Reared in Italian Intensive Systems: Nutritional Profile and Fatty Acids Composition of Longissimus lumborum Muscle

Recently, the quality of beef has received great attention, and health concerns have been focused on fatty acid composition in relation to dietary requirements. The present work aims to evaluate the effect of omega-3 fatty acids (FA) lipid supplement in beef diet on the nutritional characteristics of Longissimus lumborum (LL) muscle. One hundred and eighty Charolais beef were divided in two groups: the control group (CON) received a basal diet and the second one (TR) an isoenergetic diet containing the omega-3 supplement. Dietary treatment did not affect (p > 0.05) growth performances, carcass characteristics and LL colour indices. Cholesterol content resulted lower (p < 0.001) in LL muscle from TR group than CON. The omega-3 FA and conjugated linoleic acid content were higher (p < 0.001) in LL muscle from TR than CON. As expected, LL muscle from TR group showed an increased value of malondialdehyde than CON during refrigerated storage, anyway, remaining within the threshold value of 1 mg/kg meat. In conclusion, the lipid supplement, rich in omega-3 FA improves the fatty acid profile and decreases cholesterol content of LL muscle. This feeding practice is suggested to enhance the nutritional value of meat from beef reared in intensive condition, improving the consumer’s health.