Influence of dietary carbohydrate and fat on LDL and HDL particle distributions

The link between the risk of cardiovascular diseases and the intake of different types of dietary carbohydrates in Iranian adults

Background

The risk of cardiovascular diseases (CVDs) may be influenced by dietary carbohydrates. The aim of this study was to investigate the link between CVDs and the intake of carbohydrates.

Methods

In this cross-sectional study, data was extracted from the Prospective Epidemiologic Research Studies in Iran (PERSIAN) cohort in Sabzevar, Iran. A total of 4241 adults, including 1535 patients with CVDs and 2706 people without CVDs, were included. A validated 237-item food frequency questionnaire was used to estimate the intake of different types of dietary carbohydrates.

Results

A positive association was found between stroke and dietary intake of starch (OR = 1.108; 95% CI, 1.005-1.220; P = 0.039). Additionally, a negative association was found between stroke and dietary intake of sucrose (OR = 0.97; 95%CI, 0.94-0.99; P = 0.037). No association was found between other types of CVDs and the intake of different types of carbohydrates.

Conclusion

This study provided some evidence for the association between CVDs and different types of dietary carbohydrates. Consumption of starch may increase the risk of stroke, while a higher intake of sucrose may decrease the risk of stroke. Further studies are warranted.

Exploring the L-shaped relationship between Atherogenic Index of Plasma and depression: Results from NHANES 2005-2018

BACKGROUND

The Atherogenic Index of Plasma (AIP) is a novel metric linked to several diseases. However, there is inadequate evidence to investigate the relationship between AIP and depression. Therefore, we aim to elucidate the non-linear association between AIP and depression.

METHODS

12,453 participants from the National Health and Nutrition Examination Survey (NHANES) 2005-2018 were included. The AIP was calculated as log10 (triglycerides/high-density lipoprotein cholesterol). The Patient Health Questionnaire (PHQ-9) was used to identify depression (PHQ-9 ≥ 10). Weighted multivariate logistic regression, restricted cubic splines (RCS) models, subgroup analysis, and interaction tests were employed to reveal the relationship between AIP and depression.

RESULTS

AIP was found to be significantly correlated with depression. In the fully adjusted model, elevated AIP levels were associated with higher odds of depression (odds ratio [OR] = 1.50; 95 % CI: 1.06-2.12). The RCS analysis indicated an L-shaped pattern in the relationship between depression and AIP, with inflection points at -0.289. Beyond this inflection point, individuals with elevated AIP levels were associated with higher odds of depression (OR = 2.25; 95 % CI: 1.49-3.39). Notably, the association was particularly pronounced among individuals with diabetes.

LIMITATION

This cross-sectional study is unable to establish causal relationships.

CONCLUSION

There was an L-shaped association between AIP and depression among US adults. AIP has the potential value as a biological marker for depression, and maintaining AIP values below a certain threshold may help in managing depression.

Impact of very low carbohydrate ketogenic diets on cardiovascular risk factors among patients with type 2 diabetes; GRADE-assessed systematic review and meta-analysis of clinical trials

OBJECTIVE

This study was designed to evaluate the impact of VLCKD on cardiovascular risk factors in patients with T2DM.

METHODS

Until March 2024, extensive searches were conducted on PubMed, Scopus, Web of Science, Embase, and other relevant databases. The purpose was to identify clinical trials examining the impact of VLCKD on glycemic control, lipid profile, and blood pressure. The GRADE (Grading of Recommendations Assessment, Development, and Evaluation) method was used to assess the evidence's degree of certainty.

RESULTS

Our initial search found a total of 2568 records and finally 29 trials were included in final analysis. Our results showed that adherence from VLCKD led to significant reduction in fasting blood sugar (WMD= -11.68 mg/dl; 95% CI: -18.79, -4.56; P = 0.001), HbA1c (WMD= -0.29; 95% CI: -0.44, -0.14; P < 0.001), HOMA-IR(WMD= -0.71; 95% CI: -1.14, -0.29; P = 0.001), insulin (WMD= -1.45; 95% CI: -2.54, -0.36; P = 0.009), triglyceride (WMD= -17.95; 95% CI: -26.82, -9.07; P < 0.001), systolic blood pressure (WMD= -2.85, 95% CI: -4.99, -0.71; P = 0.009) and diastolic blood pressure (WMD= -1.40; 95% CI: -2.66, -0.13; P = 0.03). We also found a significant increase in high-density lipoprotein (HDL) level after adherence from VLCKD diet (WMD = 3.93, 95% CI: 2.03, 5.84; P = 0.000). We couldn't find any significant differences between groups in term of LDL and total cholesterol levels.

CONCLUSION

People following a VLCKD experience a more significant improvement in cardiovascular risk factors when compared to individuals on control diets.

HDL-Cholesterol Subfraction Dimensional Distribution Is Associated with Cardiovascular Disease Risk and Is Predicted by Visceral Adiposity and Dietary Lipid Intake in Women

HDL-cholesterol quality, including cholesterol distribution in HDL subfractions, is emerging as a key discriminant in dictating the effects of these lipoproteins on cardiovascular health. This study aims at elucidating the relationship between cholesterol distribution in HDL subfractions and CVD risk factors as well as diet quality and energy density in a population of pre- and postmenopausal women. Seventy-two women aged 52 ± 6 years were characterized metabolically and anthropometrically. Serum HDL-C subfractions were quantified using the Lipoprint HDL System. Cholesterol distribution in large HDL subfractions was lower in overweight individuals and study participants with moderate to high estimated CVD risk, hypertension, or insulin resistance. Cholesterol distribution in large, as opposed to small, HDL subfractions correlated negatively with insulin resistance, circulating triglycerides, and visceral adipose tissue (VAT). VAT was an independent positive and negative predictor of cholesterol distribution in large and small HDL subfractions, respectively. Furthermore, an increase in energy intake could predict a decrease in cholesterol levels in large HDL subfractions while lipid intake positively predicted cholesterol levels in small HDL subfractions. Cholesterol distribution in HDL subfractions may represent an additional player in shaping CVD risk and a novel potential mediator of the effect of diet on cardiovascular health.

Glycemic Index, Glycemic Load and Dyslipidemia in Adolescents from Chiapas, Mexico

Cardiovascular disease risk throughout the life course is increased by abnormal blood lipid levels in youth. The dietary glycemic index (GI) and glycemic load (GL) during adolescence might be related to abnormal blood lipids. This study aimed to analyze the association between dietary GI, GL and dyslipidemia in adolescents from two marginalized regions of Chiapas, Mexico. A cross-sectional study was conducted with 213 adolescents. Food intake was assessed using 24 h recalls. The association between dyslipidemia and dietary GI or GL was tested by using logistic regression models. Low HDL-c was the most prevalent risk factor (47.4%), followed by hypertriglyceridemia (25.4%). In this population, overall dietary GI was not associated with dyslipidemia. A high dietary GL was associated with 2.39 higher odds of low HDL-c (95% CI: 1.21-4.74) when compared to low GL. Female adolescents with high dietary GL had 3.20 higher odds of hypertriglyceridemia (95% CI: 1.03-9.88), whereas no association was found for males. No associations were observed between overall dietary GL and total cholesterol or LDL-c. In adolescents from urban and rural communities in Chiapas, a high dietary GL was associated with a detrimental effect on HDL-c. In female adolescents, high GL was associated with hypertriglyceridemia.

Is hypertriglyceridemia a reliable indicator of cholesterol-depleted Apo B particles?

OBJECTIVES

Because cholesterol-depleted Apo B particles are thought to be a hallmark of hypertriglyceridemia, American, Canadian and European Lipid Guidelines suggest screening for Apo B only in patients with hypertriglyceridemia. Accordingly, this study examines the relationship of triglycerides to the LDL-C/Apo B and non-HDL-C/Apo B ratios.

METHODS

The study cohort consisted of 6272 NHANES subjects adjusted for a weighted sample size of 150 million subjects without previously diagnosed cardiac disease. Data was reported by LDL-C/Apo B tertiles as weighted frequencies and percent. Sensitivity, specificity, negative predictive and positive predictive values were calculated for triglycerides thresholds of >150 mg/dL and >200 mg/dL. The range of values of Apo B for decisional levels of LDL-C and non-HDL-C were also determined RESULTS: Among patients with triglycerides >200 mg/dL, 75.9% were amongst the lowest LDL-C/Apo B tertile. However, this represents only 7.5% of the total population. Of patients with the lowest LDL-C/Apo B ratio, 59.8% had triglycerides <150 mg/dL. Moreover, there was an inverse relationship between non-HDL-C/Apo B such that elevated triglycerides were associated with the highest tertile of non-HDL-C/Apo B. Finally, the range of values of Apo B for decisional levels of LDL-C and non-HDL-C was determined and is so broad- 30.3-40.6 mg/dl Apo B for different levels of LDL-C and 19.5 to 27.6 mg/dl Apo B for different levels of non-HDL-C- that neither is an adequate clinical surrogate for Apo B.

CONCLUSION

Plasma triglycerides should not be used to restrict the measurement of Apo B since cholesterol-depleted Apo B particles may be present at any level of triglyceride.

Effects of a high-fat diet on the growth performance, lipid metabolism, and the fatty acids composition of liver and skin fat in Pekin ducks aged from 10 to 40 days

This study aimed to investigate the effect of a high-fat diet on the growth performance, serum, liver, and skin lipid metabolism as well as the fatty acids composition of liver and skin fat in Pekin ducks from 10 to 40 d of age based on a pair-fed group. Two hundred forty healthy male ducks (10 d old, 470.53 ± 0.57 g) were randomly divided into 3 groups (8 replicates per cage of 10 ducks): a normal diet (ND, 3% fat), a high-fat diet (HFD, 9% fat), and a pair-fed diet (PFD, given the ND in an amount equal to that consumed of the HFD to eliminate the effects of feed intake). The results were as follows: compared to ND feeding, HFD feeding significantly decreased (P < 0.05) the feed intake and feed:gain ratio (F:G), along with serum triglyceride and nonesterified fatty acid contents. When compared with the ND and PFD, the HFD significantly decreased (P < 0.05) the liver weight and inhibited hepatic de novo lipogenesis (glucose-6-phosphate dehydrogenase and malate dehydrogenase activities), β-oxidation (carnitine palmitoyltransferase-1 content), and decreased saturated fatty acids and monounsaturated fatty acids deposition. Moreover, the HFD significantly increased (P < 0.05) the total fat content, lipid droplet area, and polyunsaturated fatty acids (PUFAs) content in the liver, as well as the abdominal fat weight, subcutaneous fat weight, the total fat and PUFAs content in skin fat. These results suggested that the HFD improved feed efficiency, which was related to HFD feeding inhibiting hepatic de novo lipogenesis and β-oxidation and promoting the deposition of fat in skin as well as altering the fatty acids composition of the liver and skin fat in Pekin ducks.

Mouse feeding study and microbiome analysis of sourdough bread for evaluation of its health effects

Sourdough bread fermented with yeast and lactic acid bacteria (LAB) is thought to have various beneficial health effects. However, its beneficial effects were not fully evaluated with in vivo mouse model. To evaluate these effects in vivo, a mouse feeding study and microbiome analysis of white bread containing 40% sourdough (WBS) and yeast-leavened white bread (WB) were performed. Although feed consumption and body weight increased with WBS, the glycemic index was reduced, suggesting a diabetes-lowering effect, probably due to the presence of dietary fiber and short-chain fatty acids (SCFA). In addition, a mineral absorption test showed that WBS increased magnesium absorption owing to phytate degradation during fermentation. Interestingly, WBS decreased total cholesterol and triglycerides, probably due to the dietary fiber and SCFA in LAB. In addition, the ratio of low- and high-density lipoprotein was decreased in WBS, implying potential risk reduction for cardiovascular disease. An immunomodulatory assay of WBS revealed that pro-inflammatory cytokines TNF-α and IL-6 were decreased, suggesting anti-inflammatory activity. Gluten degradation by fermentation and antioxidation activity of menaquinol/ubiquinol by gut microbiota also supported the anti-inflammatory activity of sourdough bread. Furthermore, some beneficial gut bacteria, including Akkermansia, Bifidobacterium, and Lactobacillus, were increased in WBS. In particular, Akkermansia has been associated with anti-inflammatory properties. Consequently, WBS has beneficial effects on health, including decreased glycemic index and cholesterol, increased mineral availability and absorption, anti-inflammatory properties, and establishment of healthy gut microbiota.

Reshaping the Gut Microbiota Through Lifestyle Interventions in Women with PCOS: A Review

Polycystic ovary syndrome (PCOS) is an endocrine disorder evolving as a global threat to women's health. However, its multifactorial etiology causes difficulty in eliminating it. The interrelation between the gut microbiota and metabolic disorders has been trending recently, giving rise to new opportunities on the etiology and pathogenesis of PCOS. Lifestyle interventions such as healthy diet, physical exercises, and behavioral interventions such as regulation of stress and sleep cycles have been identified to improve the symptoms of PCOS across the endocrinological, metabolic and psychological scales and are recommended as the first line of treatment for PCOS. The impact of the unhealthy lifestyle factors on intestinal dysbiosis that cause PCOS is summarized in this review. This review also provides an insight on the therapeutic approaches that primarily target the gut microbiota and offers novel gut microflora-associated treatment strategies for PCOS. Further, this survey also highlights the need for the implementation of lifestyle management strategies and strongly recommends a healthy and stress-free lifestyle to promote gut health and manage PCOS.

Molecular characterization of farnesoid X receptor alpha in Megalobrama amblycephala and its potential roles in high-carbohydrate diet-induced alterations of bile acid metabolism

Farnesoid X receptorα (FXRα) plays a central role in maintaining the bile acid homeostasis in mammals, while relevant processes are still poorly interpreted in aquatic species. This study was conducted to characterize the fxrα gene in a cyprinidae species: blunt snout bream (Megalobrama amblycephala), and investigate its potential roles in bile acid metabolism. The Fxrα protein contains one DNA binding domain, one ligand binding domain, one His-Try "switch" and two modifies residues. A high degree of conservation (53.18-100.00 %) was observed in the Fxrα protein among most aquatic species and higher vertebrates. The transcription of fxrα was mainly observed in intestine, liver and kidney. Then fish (35.0 ± 0.15 g) were fed two diets containing 33 % and 45 % carbohydrate levels for 12weeks. High-carbohydrate diet significantly elevated the total cholesterol concentrations in plasma, liver and hindgut as well as the triglyceride concentrations in both liver and hindgut, but decreased the total bile acid concentrations in plasma, liver and hindgut. High dietary carbohydrate levels also significantly enhanced hepatic transcriptions of 3-hydroxy-3-methylglutaryl-CoA reductase (the rate-limiting enzyme in cholesterol synthesis), and those of fxrα (a bile acid receptor) and multidrug resistance associated protein 2 (a bile acid transporter) in hindgut. Furthermore, high dietary carbohydrate levels significantly decreased the transcriptions of cholesterol 7α-hydroxylase (the rate-limiting enzyme in bile acid synthesis) and organic anion-transporting polypeptides (a bile acid transporter) in liver as well as that of takeda G-protein-coupled bile acid receptor in hindgut. The results demonstrated that the fxrα gene of blunt snout bream is highly conserved compared with other vertebrates. Besides, high dietary carbohydrate levels increased total cholesterol concentrations, and up-regulated the transcription of fxrα, thus decreasing the biosynthesis and reabsorption of bile acids by mediating various target genes.

Prevalence of dyslipidemias and food consumption: a population-based study

This study aimed to assess the prevalence of dyslipidemia and its association with an adequate intake of carbohydrates, saturated, monounsaturated, trans, and omega-3 fats among adults living in Viçosa, Minas Gerais, Brazil. This is a cross-sectional study with 884 adults aged 20 to 59 years. Sociodemographic, food intake, anthropometric, and biochemical data were collected. Associations between study variables were investigated by the chi-square test. There was a high prevalence of dyslipidemia in the study population (64.25%), with most individuals having abnormal levels of at least one serum lipid component. Inadequate intakes of saturated, trans, and monounsaturated fats and carbohydrates were predominant. It is noteworthy that omega-3 intake levels were adequate in most individuals. Eutrophic adults showed a higher prevalence of excessive intake of saturated and trans fats. It was found that 38.7% of individuals with low levels of High Density Lipoprotein cholesterol (HDL-c) had an excessive intake of saturated fat. Most individuals with high triglyceride levels or high triglyceride/HDL-c ratios had an insufficient intake of monounsaturated fat. Further studies are needed to evaluate other factors that may influence dietary patterns.

Lactobacillus johnsonii N6.2 and Blueberry Phytophenols Affect Lipidome and Gut Microbiota Composition of Rats Under High-Fat Diet

Obesity is considered a primary contributing factor in the development of many diseases, including cancer, diabetes, and cardiovascular illnesses. Phytochemical-rich foods, associated to healthy gastrointestinal microbiota, have been shown to reduce obesity and associated comorbidities. In the present article, we describe the effects of the probiotic Lactobacillus johnsonii N6.2 and blueberry extracts (BB) on the gut microbiota and lipid profile of rats under a high-fat (HF) or low-calorie (LC) diet. L. johnsonii was found to increase the levels of long chain fatty acids (LCFA) in the serum of all animals under HF diet, while reduced LCFA concentrations were observed in the adipose tissue of animals under HF diet supplemented with BB extracts. All animals under HF diet also showed lower protein levels of SREBP1 and SCAP when treated with L. johnsonii. The gut microbiota diversity, β-diversity was significantly changed by L. johnsonii in the presence of BB. A significant reduction in α-diversity was observed in the ileum of animals under HF diet supplemented with L. johnsonii and BB, while increased α-diversity was observed in the ilium of animals under LC diet supplemented with L. johnsonii or BB. In summary, L. johnsonii and BB supplementation induced significant changes in gut microbiota diversity and lipid metabolism. The phospholipids pool was the lipidome component directly affected by the interventions. The ileum and colon microbiota showed clear differences depending on the diet and the treatments examined.

Effect of carbohydrate-restricted dietary interventions on LDL particle size and number in adults in the context of weight loss or weight maintenance: a systematic review and meta-analysis

BACKGROUND

LDL particle size and number (LDL-P) are emerging lipid risk factors. Nonsystematic reviews have suggested that diets lower in carbohydrates and higher in fats may result in increased LDL particle size when compared with higher-carbohydrate diets.

OBJECTIVES

This study aimed to systematically review available evidence and conduct meta-analyses of studies addressing the association of carbohydrate restriction with LDL particle size and LDL-P.

METHODS

We searched 6 electronic databases on 4 January, 2021 for randomized trials of any length that reported on dietary carbohydrate restriction (intervention) compared with higher carbohydrate intake (control). We calculated standardized mean differences (SMDs) in LDL particle size and LDL-P between the intervention and control groups of eligible studies, and pooled effect sizes using random-effects models. We performed prespecified subgroup analyses and examined the effect of potential explanatory factors. Internal validity and publication bias were assessed using Cochrane's risk-of-bias tool and funnel plots, respectively. Studies that could not be meta-analyzed were summarized qualitatively.

RESULTS

This review summarizes findings from 38 randomized trials including a total of 1785 participants. Carbohydrate-restricted dietary interventions were associated with an increase in LDL peak particle size (SMD = 0.50; 95% CI: 0.15, 0.86; P < 0.01) and a reduction in LDL-P (SMD = -0.24; 95% CI: -0.43, -0.06; P = 0.02). The effect of carbohydrate-restricted dietary interventions on LDL peak particle size appeared to be partially explained by differences in weight loss between intervention groups and exploratory analysis revealed a shift from small dense to larger LDL subclasses. No statistically significant association was found between carbohydrate-restricted dietary interventions and mean LDL particle size (SMD = 0.20; 95% CI: -0.29, 0.69; P = 0.37).

CONCLUSIONS

The available evidence indicates that dietary interventions restricted in carbohydrates increase LDL peak particle size and decrease the numbers of total and small LDL particles.This review was registered at www.crd.york.ac.uk/prospero/ as CRD42020188745.

Effect of a late afternoon/early evening bout of aerobic exercise on postprandial lipid and lipoprotein particle responses to a high-sugar meal breakfast the following day in postmenopausal women: a randomized cross-over study

High-sugar consumption is related to dyslipidemia. How acute exercise affects postprandial lipid and lipoprotein particle responses to a high-sugar meal (HSM) in postmenopausal women is unclear. We examined the effects of a late afternoon/early evening bout of aerobic exercise on postprandial lipid and lipoprotein particle responses to a HSM breakfast the following day in 22 postmenopausal women. Subjects underwent exercise (EX) and no exercise (NE) conditions in the evening 13-16 h before the HSM breakfast consumption, in a random order. During the EX condition, subjects performed supervised aerobic exercise for 60 min at 75% of age-predicted maximum heart rate. The HSM (75.6% carbohydrate and 33% energy needs) was consumed after a 12-h fast. Serum lipids and lipoproteins were assessed at baseline and postprandially (60, 120, 180 min). Repeated measures analysis showed significantly lower area under the curve (geometric means [95% CI]) for triglycerides (TG) (2.96[2.43, 3.61] vs. 3.24[2.70, 3.88] mmol/L*hr; p = 0.049) and very low density lipoprotein particles (VLDLP) (114.6[88.2, 148.9] vs. 134.3[108.1, 166.9] nmol/L*hr; p = 0.02) during the EX versus NE condition. There were no condition effects for other variables. In conclusion, the EX versus NE condition lowered postprandial AUC for TG and VLDLP following HSM consumption in postmenopausal women.Trial Registration: ClinicalTrials.gov Identifier: NCT02919488.

Effect of a very low-carbohydrate ketogenic diet vs recommended diets in patients with type 2 diabetes: a meta-analysis

CONTEXT

There is renewed interest in using very low-carbohydrate ketogenic (VLCK) diets to manage diabetes. Many clinical trials have been published, often with mixed results.

OBJECTIVE

This meta-analysis compares the effect of a VLCK diet on glycemic control, body weight, lipid profile, medication use, and dropouts with that of recommended diets for 12 weeks or longer in people with type 2 diabetes.

DATA SOURCES

Ovid MEDLINE, Ovid Embase, CENTRAL, and CINAHL databases were searched (January 1980 through September 2019).

STUDY SELECTION

Two authors independently reviewed search results to select randomized controlled trials (RCTs) comparing a VLCK diet (carbohydrate intake < 50 g/d or < 10% of total energy) with any recommended diet for type 2 diabetes in adults. Discrepancies were resolved after consulting with the third author.

DATA EXTRACTION

Eight RCTs with 648 participants were identified.

RESULTS

Compared with control diets, the VLCK diet resulted in a greater decrease in hemoglobin A1c after 3 months (weighted mean difference[WMD]: -6.7 mmol/mol; 95%CI, -9.0 to -4.4) (WMD: -0.61%; 95%CI, -0.82 to -0.40; P < 0.001; moderate-certainty evidence) and after 6 months (WMD: -6.3 mmol/mol; 95%CI, -9.3 to -3.5) (WMD: -0.58%; 95%CI, -0.85 to -0.32; low-certainty evidence). There was a significantly greater weight loss with the VLCK diet after 3 months (WMD: -2.91 kg; 95%CI, -4.88 to -0.95; low-certainty evidence) and after 6 months (WMD: -2.84 kg; 95%CI, -5.29 to -0.39; low-certainty evidence). The VLCK diet was not better than a control diet after 12 months. It was superior in decreasing triglyceride levels, increasing high-density lipoprotein cholesterol levels, and reducing the use of antidiabetic medications for up to 12 months.

CONCLUSION

The VLCK diet appears to control glycemia and decrease body weight for up to 6 months in people with obesity and diabetes. Beneficial changes in serum triglycerides and high-density lipoprotein cholesterol, along with reductions in antidiabetic medications, continued in the VLCK group until 12 months. However, the quality of currently available evidence is not sufficient to recommend VLCK diets. A major limitation of the VLCK diet is patients' lack of adherence to carbohydrate restriction.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42020154700.

Perspective: The Saturated Fat-Unsaturated Oil Dilemma: Relations of Dietary Fatty Acids and Serum Cholesterol, Atherosclerosis, Inflammation, Cancer, and All-Cause Mortality

PUFAs are known to regulate cholesterol synthesis and cellular uptake by multiple mechanisms that do not involve SFAs. Polymorphisms in any of the numerous proteins involved in cholesterol homeostasis, as a result of genetic variation, could lead to higher or lower serum cholesterol. PUFAs are susceptible to lipid peroxidation, which can lead to oxidative stress, inflammation, atherosclerosis, cancer, and disorders associated with inflammation, such as insulin resistance, arthritis, and numerous inflammatory syndromes. Eicosanoids from arachidonic acid are among the most powerful mediators that initiate an immune response, and a wide range of PUFA metabolites regulate numerous physiological processes. There is a misconception that dietary SFAs can cause inflammation, although endogenous palmitic acid is converted to ceramides and other cell constituents involved in an inflammatory response after it is initiated by lipid mediators derived from PUFAs. This article will discuss the many misconceptions regarding how dietary lipids regulate serum cholesterol, the fact that all-cause death rate is higher in humans with low compared with normal or moderately elevated serum total cholesterol, the numerous adverse effects of increasing dietary PUFAs or carbohydrate relative to SFAs, as well as metabolic conversion of PUFAs to SFAs and MUFAs as a protective mechanism. Consequently, dietary saturated fats seem to be less harmful than the proposed alternatives.

Cardiovascular Risk Factor Reduction in First Responders Resulting From an Individualized Lifestyle and Blood Test Program: A Randomized Controlled Trial

OBJECTIVE

We tested the hypothesis that a lifestyle program would improve risk factors linked to cardiovascular disease (CVD) in first responders.

METHODS

A 1-year cluster-randomized controlled clinical trial in 10 cities. Participants were 175 first responders, with increased waist circumference and/or low levels of large (α1) high-density lipoprotein (HDL) particles. The intervention group received personalized online tools and access to telephonic coaching sessions.

RESULTS

At 1 year the intervention significantly reduced body weight (P = 0.004) and waist circumference (P = 0.002), increased α1 HDL (P = 0.01), and decreased triglyceride (P = 0.005) and insulin concentrations (P = 0.03). Program adherence was associated with weight loss (P = 0.0005) and increases in α1 HDL (P = 0.03).

CONCLUSIONS

In first responders, a personalized lifestyle intervention significantly improved CVD risk factors in proportion to program adherence. Changes in large HDL particles were more sensitive indicators of lifestyle changes than HDL-cholesterol measurement.

CLINICAL TRIAL REGISTRATION NUMBER

ClinicalTrials.gov: NCT03322046.

Glycemic index, glycemic load, and risk of coronary heart disease: a pan-European cohort study

BACKGROUND

High carbohydrate intake raises blood triglycerides, glucose, and insulin; reduces HDLs; and may increase risk of coronary heart disease (CHD). Epidemiological studies indicate that high dietary glycemic index (GI) and glycemic load (GL) are associated with increased CHD risk.

OBJECTIVES

The aim of this study was to determine whether dietary GI, GL, and available carbohydrates are associated with CHD risk in both sexes.

METHODS

This large prospective study-the European Prospective Investigation into Cancer and Nutrition-consisted of 338,325 participants who completed a dietary questionnaire. HRs with 95% CIs for a CHD event, in relation to intake of GI, GL, and carbohydrates, were estimated using covariate-adjusted Cox proportional hazard models.

RESULTS

After 12.8 y (median), 6378 participants had experienced a CHD event. High GL was associated with greater CHD risk [HR 1.16 (95% CI: 1.02, 1.31) highest vs. lowest quintile, p-trend 0.035; HR 1.18 (95% CI: 1.07, 1.29) per 50 g/day of GL intake]. The association between GL and CHD risk was evident in subjects with BMI (in kg/m2) ≥25 [HR: 1.22 (95% CI: 1.11, 1.35) per 50 g/d] but not in those with BMI <25 [HR: 1.09 (95% CI: 0.98, 1.22) per 50 g/d) (P-interaction = 0.022). The GL-CHD association did not differ between men [HR: 1.19 (95% CI: 1.08, 1.30) per 50 g/d] and women [HR: 1.22 (95% CI: 1.07, 1.40) per 50 g/d] (test for interaction not significant). GI was associated with CHD risk only in the continuous model [HR: 1.04 (95% CI: 1.00, 1.08) per 5 units/d]. High available carbohydrate was associated with greater CHD risk [HR: 1.11 (95% CI: 1.03, 1.18) per 50 g/d]. High sugar intake was associated with greater CHD risk [HR: 1.09 (95% CI: 1.02, 1.17) per 50 g/d].

CONCLUSIONS

This large pan-European study provides robust additional support for the hypothesis that a diet that induces a high glucose response is associated with greater CHD risk.

Review article: the impact of liver-directed therapies on the atherogenic risk profile in non-alcoholic steatohepatitis

BACKGROUND

Patients with non-alcoholic fatty liver disease (NAFLD), the most common cause of chronic liver disease, are at higher risk of cardiovascular disease (CVD) and associated mortality. Therefore, it is important to understand how new therapies for non-alcoholic steatohepatitis (NASH) may impact CVD risk factors in these patients.

AIMS

To summarise the effects of drug therapies on lipid and lipoprotein levels in patients with NASH and provide insight into the potential mechanisms for the observed changes.

METHODS

PubMed searches of the literature were performed and results were compiled.

RESULTS

Recent clinical trials have highlighted the safety and efficacy of drug candidates for the treatment of NASH. Several agents have shown improvements in the histological features of NASH and liver function. Pioglitazone, a drug that is currently available for type 2 diabetes and may be useful for NASH, exhibits beneficial effects on lipids. However, agents such as farnesoid X receptor agonists, which are in development for NASH, may adversely affect circulating lipids and lipoproteins.

CONCLUSIONS

NASH is a multi-system disease with a disproportionate CVD burden. Current and future drugs for NASH have had variable impact on the atherogenic risk profile. Potential co-administration of a statin may help mitigate the negative impact of some of these therapies on lipid and lipoprotein levels.

Quantile-specific heritability of high-density lipoproteins with implications for precision medicine

BACKGROUND

We have previously shown that the effect of a high-density lipoprotein (HDL) genetic risk score depends on whether the phenotype (HDL cholesterol) is high or low relative to its distribution (quantile-dependent expressivity).

OBJECTIVE

Evidence for quantile-dependent expressivity was sought using a more inclusive genetic measure (quantile-specific heritability, h²) in a larger population (Framingham cohort).

METHODS

Quantile regression was used to test whether the offspring-parent (β_OP) and full-sib (β_FS) regression slopes increased with the percentiles of the offspring's HDL distribution in 10,650 parent-offspring pairs and 2130 sibships. Quantile-specific heritability was estimated by 2β_OP/(1 + r_spouse) and [(8β_FSr_spouse + 1)^0.5-1]/(2r_spouse), where r_spouse is the spouse correlation.

RESULTS

HDL cholesterol heritability estimated from β_OP increased significantly (P = 4.2 × 10^-5) from the 10^th (h² ± SE: 0.44 ± 0.03), 25^th (0.45 ± 0.03), 50^th (0.47 ± 0.03), and 75^th (0.56 ± 0.04) to the 90^th percentiles (0.65 ± 0.06) of the offspring's age- and sex-adjusted HDL cholesterol distribution. Heritability estimated from β_FS also increased significantly with the percentiles of the offspring's HDL cholesterol (P = .002), apo A1 (P = .006), HDL2 cholesterol (P = .003), and HDL3 cholesterol distribution (P = .02). Consistent with quantile-dependent expressivity, published pharmacologic and nutritional interventions that raised (eg, statin, fibrates, estrogen replacement therapy, efavirenz, and dietary fat) or lowered HDL cholesterol concentrations (tamoxifen, dietary carbohydrate) correspondingly increased and decreased genetic effects.

CONCLUSION

HDL cholesterol heritability increased with increasing percentile of the offspring's HDL distribution. Whereas precision medicine is based on the premise that genetic markers identify patients most likely to benefit from drugs and diet, quantile-dependent expressivity postulates that the strong signals from these genetic markers simply trace the heritability increase with increasing plasma HDL concentrations. Thus, quantile-dependent expressivity provides an alternative interpretation to these genotype-specific effects.

Urtica dioica Whole Vegetable as a Functional Food Targeting Fat Accumulation and Insulin Resistance-a Preliminary Study in a Mouse Pre-Diabetic Model

The shoot of Urtica dioica is used in several cultures as a vegetable or herb. However, not much has been studied about the potential of this plant when consumed as a whole food/vegetable rather than an extract for dietary supplements. In a 12-week dietary intervention study, we tested the effect of U. dioica vegetable on high fat diet induced obesity and insulin resistance in C57BL/6J mice. Mice were fed ad libitum with isocaloric diets containing 10% fat or 45% fat with or without U. dioica. The diet supplemented with U. dioica attenuated high fat diet induced weight gain (p < 0.005; n = 9), fat accumulation in adipose tissue (p < 0.005; n = 9), and whole-body insulin resistance (HOMA-IR index) (p < 0.001; n = 9). Analysis of gene expression in skeletal muscle showed no effect on the constituents of the insulin signaling pathway (AKT, IRS proteins, PI3K, GLUT4, and insulin receptor). Notable genes that impact lipid or glucose metabolism and whose expression was changed by U. dioica include fasting induced adipocyte factor (FIAF) in adipose and skeletal muscle, peroxisome proliferator-activated receptor-α (Ppar-α) and forkhead box protein (FOXO1) in muscle and liver, and Carnitine palmitoyltransferase I (Cpt1) in liver (p < 0.01). We conclude that U. dioica vegetable protects against diet induced obesity through mechanisms involving lipid accumulation and glucose metabolism in skeletal muscle, liver, and adipose tissue.

Dietary Carbohydrate Constituents Related to Gut Dysbiosis and Health

Recent studies report that microbiota in the human intestine play an important role in host health and that both long- and short-term diets influence gut microbiota. These findings have fueled interest in the potential of food to promote health by shaping the intestinal microbiota. Despite the fact that large populations in Asia consume high quantities of carbohydrates, such diets have been ignored in comparison to the attention received by Western diets containing high quantities of fat and animal protein. We gathered data that suggest an association between imbalanced high-carbohydrate intake and gut microbiota and host health. In this review, we identify not only the effect of total carbohydrates on the intestinal microbiota specifically and the health of their hosts in general, but also how specific types of carbohydrates influence both factors.

Dietary fats and cardiometabolic disease: mechanisms and effects on risk factors and outcomes

The effect of dietary fats on cardiometabolic diseases, including cardiovascular diseases and type 2 diabetes mellitus, has generated tremendous interest. Many earlier investigations focused on total fat and conventional fat classes (such as saturated and unsaturated fats) and their influence on a limited number of risk factors. However, dietary fats comprise heterogeneous molecules with diverse structures, and growing research in the past two decades supports correspondingly complex health effects of individual dietary fats. Moreover, health effects of dietary fats might be modified by additional factors, such as accompanying nutrients and food-processing methods, emphasizing the importance of the food sources. Accordingly, the rapidly increasing scientific findings on dietary fats and cardiometabolic diseases have generated debate among scientists, caused confusion for the general public and present challenges for translation into dietary advice and policies. This Review summarizes the evidence on the effects of different dietary fats and their food sources on cell function and on risk factors and clinical events of cardiometabolic diseases. The aim is not to provide an exhaustive review but rather to focus on the most important evidence from randomized controlled trials and prospective cohort studies and to highlight current areas of controversy and the most relevant future research directions for understanding how to improve the prevention and management of cardiometabolic diseases through optimization of dietary fat intake.

Dietary supplement of tomato can accelerate urinary aMT6s level and improve sleep quality in obese postmenopausal women

The aim of this study was to investigate the effect of the ingestion of tomato before bed on obese postmenopausal women's urinary 6-sulphatoxymelatonin (aMT6s) level and sleep quality. We quantified melatonin concentrations in beefsteak tomato, black tomato, and two commercial tomato juices and found that beefsteak tomato contained the highest level of melatonin. In this 8-week open-label, randomized controlled dietary intervention trial, 36 subjects completed the entire trial. The tomato group ate 250 g of beefsteak tomatoes 2 h before sleep for 8 weeks. Blood and urine samples were collected at the baseline and in the 8th week and were analyzed. The Pittsburgh Sleep Quality Index (PSQI) in the tomato group significantly decreased with time (p for trend = 0.0297). After 8 weeks of the beefsteak intervention, all components of the PSQI in tomato group had significantly improved, and their aMT6s level was 10-fold significantly higher than that of the control group. Therefore, supplementation with beefsteak tomato before sleep can increase circulating melatonin and improve sleep quality in obese postmenopausal women.

A short-term religious "fast" from animal products has a minimal impact on cardiometabolic health biomarkers irrespective of concurrent shifts in distinct plant-based food groups

BACKGROUND

Plant-based diets may help improve measures of body fat, blood cholesterol, glucose metabolism, and inflammation. However, limited evidence suggests that the health effects of reducing animal products may depend on the quality of plant-based foods consumed as caloric replacements.

OBJECTIVE

This study examined how temporarily restricting consumption of meat, dairy, and egg (MDE) products for religious purposes influences cardiometabolic health biomarkers and whether any effects of MDE restriction on biomarkers are modified by concurrent shifts in calories, fish, and distinct plant-based foods.

DESIGN

This study followed a sample of 99 individuals in the United States with varying degrees of adherence to Orthodox Christian (OC) guidance to abstain from MDE products during Lent, the 48-d period prior to Easter. Dietary composition was estimated from FFQs and 7-d food records; measures of body fat, blood lipids, glucose metabolism, and inflammation were collected prior to and at the end of Lent.

RESULTS

Each serving decrease in MDE products was associated with an average -3.7% (95% CI: -5.5%, -2.0%; P < 0.0001) and -3.6% (95% CI: -5.8%, -1.3%; P = 0.003) change in fasting total and LDL blood cholesterol, respectively, which were partly explained by minor weight loss. However, the total/HDL cholesterol ratio did not significantly decrease due to an average -3.2% (95% CI: -5.8%, -0.6%; P = 0.02) change in HDL cholesterol. No associations between MDE restrictions and shifts in measures of body fat, glucose, insulin, or C-reactive protein were observed. The data could not provide evidence that changes in cardiometabolic health biomarkers in relation to MDE restriction were modified by concurrent shifts in calories, fish, or plant-based foods.

CONCLUSION

Temporary MDE restrictions practiced by this sample of OCs in the United States during Lent had minimal effects on cardiometabolic disease risk factors. Further research among larger samples of OCs is needed to understand how nutritionally distinct and complex combinations of plant-based foods may modify the health effects of religious fasting from MDE products.

Lipid findings from the Diabetes Education to Lower Insulin, Sugars, and Hunger (DELISH) Study

Background

A carbohydrate-restricted (CR) diet can improve glycemic control in people with type 2 diabetes mellitus (T2DM). There are concerns, however, that the high dietary fat content of CR diets can increase low-density lipoprotein cholesterol (LDL-C), thus increasing cardiovascular disease (CVD) risk. Quantifying CVD risk associated with changes in LDL-C in the context of CR diets is complicated by the fact that LDL-C reflects heterogeneous lipids. For example, small LDL particle number (sLDL-P) is more closely associated with CVD risk than is total LDL-C, and CR diets tend to decrease the proportion of sLDL-C in LDL-C, which standard lipid measures do not indicate. Advanced lipoprotein assays, such as nuclear magnetic resonance (NMR) testing, can subfractionate lipoproteins by size and density and may better depict the effects of CR diets on CVD risk.

Methods

Adults (N = 58) with T2DM (n = 37 women; baseline HbA1c ≥ 6.5%) completed a 6-month group-based CR diet intervention. We obtained a standard lipid panel, advanced lipoprotein assays (NMR testing), and two 24-h diet recalls at baseline and post-intervention (6 months). Participants also completed home-based blood ketone testing (a biological index of dietary adherence) during the final five weeks of the intervention.

Results

From baseline to post-intervention, participants had increased mean HDL-C, decreased triglycerides and triglyceride/HDL ratio, decreased mean sLDL-P, and increased LDL size, which reflect reductions in CVD risk (ps < 0.05). Participants did not have statistically significant changes in total cholesterol, non-HDL-C cholesterol, LDL-P, or HDL-P. Twelve participants (23.1%) had a ≥ 5% increase in sLDL-P. Exploratory analyses revealed that participants with sLDL-P increases of ≥ 5% reported larger increases in servings of red meat than participants without sLDL-P increases of ≥ 5% (+ 0.69 vs − 0.29 servings; p = 0.033). Changes in saturated fat intake were not associated with changes in sLDL-P.

Conclusions

Among most participants, we observed changes in several lipid measures consistent with decreased CVD risk. Approximately one in four participants evidenced increases in sLDL-P. Further research should clarify whether individuals with increased sLDL-P after implementing a CR diet can reverse observed increases by limiting red meat consumption.

Trial registration

ClinicalTrials.gov, NCT03207711, Registered 6/11/2017. Retrospectively registered.

Intake of starch and sugars and total and cause-specific mortality in a Japanese community: the Takayama Study

Studies on the intake of different types of carbohydrates and long-term mortality are sparse. We examined the association of starch, total and each type of sugar and free sugars with the risk of total and cause-specific mortality in a cohort of the general population in Japan. Study subjects were 29 079 residents from the Takayama Study, Japan, who responded to a self-administered questionnaire in 1992. Diet was assessed by a validated FFQ at the baseline. Mortality was ascertained during 16 years of follow-up. We noted 2901 deaths (974 cancer related and 775 cardiovascular related) in men and 2438 death (646 cancer related and 903 cardiovascular related) in women. In men, intake of starch was inversely associated with total mortality after controlling for covariates (hazard ratio (HR) for the highest quartile v. lowest quartile: 0·71; 95 % CI 0·60, 0·84; Ptrend &lt; 0·001). Intakes of total sugars, glucose, fructose, sucrose, maltose and free and naturally occurring sugars were significantly positively associated with total mortality in men (HR for the highest v. lowest quartile of total sugar: 1·27; 95 % CI 1·12, 1·45; Ptrend &lt; 0·0001). Similar relations were observed for cardiovascular mortality and non-cancer, non-cardiovascular mortality in men. In women, there was no significant association between any type of carbohydrates and mortality except that intake of free sugars was significantly positively associated with total and non-cancer, non-cardiovascular mortality. Data suggest that the high intake of starch reduces mortality, whereas the high intake of sugars, including glucose, fructose and sucrose, increases mortality in Japanese men.

Consumption of regular-fat vs reduced-fat cheese reveals gender-specific changes in LDL particle size - a randomized controlled trial

Background

Regular-fat cheese does not seem to increase low density lipoprotein cholesterol (LDL-C) concentrations compared to reduced-fat cheese. However, plasma LDL-C concentrations do not reflect levels and size of LDL particles, which might be a better predictor of cardiovascular risk.

Methods

The aim was to compare the effects of regular-fat cheese vs reduced-fat cheese and carbohydrate-rich foods on LDL particle size distribution in adults with ≥ 2 metabolic syndrome (MetS) risk factors. The study was part of a 12 weeks’ randomized controlled trial in which subjects had been randomly allocated to 1 of 3 intervention groups; regular-fat cheese (REG), reduced-fat cheese (RED) or a no-cheese/carbohydrate (CHO) group. Subjects in the REG and RED groups consumed 80 g cheese/d per 10 MJ, whereas subjects in the CHO consumed bread and jam corresponding to 90 g/d and 25 g/d per 10 MJ, respectively. Fasting blood samples at wk. 0 (baseline) and wk. 12 were analyzed for LDL particle size distribution and cholesterol content using nuclear magnetic resonance (NMR) spectroscopy.

Results

A total of 85 subjects [mean ± SD age: 54.0 ± 12.8 y; BMI: 28.7 ± 3.6 kg/m²] completed the study. Overall, regular-fat cheese did not impact lipoprotein particle number and size differently than reduced-fat cheese. In men (n = 23), the REG diet decreased total LDL particle number (LDL-P, − 223.2 ± 91.1 nmol/l, P = 0.01) compared with the RED diet. The reduction was primarily in the medium-sized LDL fraction (− 128.5 ± 51.8 nmol/l, P = 0.01). In women (n = 62), the REG diet increased the concentration of cholesterol in the small high density lipoprotein (HDL) particles compared with the CHO diet (2.9 ± 1.0 mg/dl, P = 0.006).

Conclusion

Overall, regular-fat cheese did not alter LDL particle size distribution compared to reduced-fat cheese after a 12 wk. intervention in subjects with ≥2 MetS risk factors. However, our results suggest that lipoprotein response to cheese intake is gender-specific. This warrants further investigation.

Trial registration

This trial was registered at Clinicaltrials.gov as NCT0261471. Registered 30 November 2015 - Retrospectively registered.

Differential association of dietary carbohydrate intake with metabolic syndrome in the US and Korean adults: data from the 2007-2012 NHANES and KNHANES

BACKGROUND/OBJECTIVES

The risk factors for metabolic syndrome may differ between Western and Asian countries due to their distinct dietary cultures. However, few studies have directly compared macronutrient intake and its association with the risk of metabolic syndrome in the US and Korean adults using national survey data.

SUBJECT/METHODS

Based on the data from the US and Korean versions of the 2007-2012 National Health and Nutrition Examination Survey (NHANES, KNHANES), a total of 3,324 American and 20,515 Korean adults were included. In both countries, dietary intake was measured using a 24-h dietary recall method and metabolic syndrome was defined using the National Cholesterol Education Program Adult Treatment Panel III criteria.

RESULTS

The percentages of energy intake from carbohydrate, protein, and fat were 50:16:33 in the US adults and 66:15:19 in the Korean adults. Regarding metabolic abnormalities, Korean adults in the highest quintile of carbohydrate intake showed an increased risk of metabolic syndrome in men and women, with abnormalities of reduced HDL cholesterol and elevated triglyceride levels. In contrast, the US men showed no significant association with metabolic syndrome and its abnormalities, while the US women showed an increased risk of reduced HDL cholesterol and elevated triglycerides.

CONCLUSIONS

A high carbohydrate intake is associated with metabolic abnormalities. As Korean adults consume more carbohydrate than American adults, stronger associations of dietary carbohydrate with metabolic syndrome were observed. Thus, further studies are necessary to elucidate the underlying mechanisms of different contributors to developing metabolic disease in Western and Asian populations.

A review of low-density lipoprotein cholesterol, treatment strategies, and its impact on cardiovascular disease morbidity and mortality

Cardiovascular (CV) disease is a leading cause of death worldwide, accounting for approximately 31.4% of deaths globally in 2012. It is estimated that, from 1980 to 2000, reduction in total cholesterol accounted for a 33% decrease in coronary heart disease (CHD) deaths in the United States. In other developed countries, similar decreases in CHD deaths (ranging from 19%-46%) have been attributed to reduction in total cholesterol. Low-density lipoprotein cholesterol (LDL-C) has now largely replaced total cholesterol as a risk marker and the primary treatment target for hyperlipidemia. Reduction in LDL-C levels by statin-based therapies has been demonstrated to result in a reduction in the risk of nonfatal CV events and mortality in a continuous and graded manner over a wide range of baseline risk and LDL-C levels. This article provides a review of (1) the relationship between LDL-C and CV risk from a biologic, epidemiologic, and genetic standpoint; (2) evidence-based strategies for LDL-C lowering; (3) lipid-management guidelines; (4) new strategies to further reduce CV risk through LDL-C lowering; and (5) population-level and health-system initiatives aimed at identifying, treating, and lowering lifetime LDL-C exposure.

Metabolic and physiologic effects from consuming a hunter-gatherer (Paleolithic)-type diet in type 2 diabetes

BACKGROUND/OBJECTIVES

The contemporary American diet figures centrally in the pathogenesis of numerous chronic diseases--'diseases of civilization'--such as obesity and diabetes. We investigated in type 2 diabetes whether a diet similar to that consumed by our pre-agricultural hunter-gatherer ancestors ('Paleolithic' type diet) confers health benefits.

SUBJECTS/METHODS

We performed an outpatient, metabolically controlled diet study in type 2 diabetes patients. We compared the findings in 14 participants consuming a Paleo diet comprising lean meat, fruits, vegetables and nuts, and excluding added salt, and non-Paleolithic-type foods comprising cereal grains, dairy or legumes, with 10 participants on a diet based on recommendations by the American Diabetes Association (ADA) containing moderate salt intake, low-fat dairy, whole grains and legumes. There were three ramp-up diets for 7 days, then 14 days of the test diet. Outcomes included the following: mean arterial blood pressure; 24-h urine electrolytes; hemoglobin A1c and fructosamine levels; insulin resistance by euglycemic hyperinsulinemic clamp and lipid levels.

RESULTS

Both groups had improvements in metabolic measures, but the Paleo diet group had greater benefits on glucose control and lipid profiles. Also, on the Paleo diet, the most insulin-resistant subjects had a significant improvement in insulin sensitivity (r = 0.40, P = 0.02), but no such effect was seen in the most insulin-resistant subjects on the ADA diet (r = 0.39, P = 0.3).

CONCLUSIONS

Even short-term consumption of a Paleolithic-type diet improved glucose control and lipid profiles in people with type 2 diabetes compared with a conventional diet containing moderate salt intake, low-fat dairy, whole grains and legumes.

ISSFAL 2014 Debate: It Is Time to Update Saturated Fat Recommendations

This paper summarizes a debate on whether to update recommendations for the consumption of saturated fatty acids (SFA); this debate was held at the 11th congress of the International Society for the Study of Fatty Acids and Lipids in Stockholm, Sweden, June 28-July 2, 2014. Recommendations to reduce SFA intakes are based largely on the premise that high intakes of SFA raise low-density lipoprotein (LDL)-cholesterol levels, which in turn increase the risk of coronary heart disease (CHD). Several systematic reviews question whether reducing SFA intakes lowers CHD risk. Arguing to revise SFA recommendations, Philippe Legrand noted that SFA are heterogeneous in structure and function, are synthesized de novo by humans and only certain SFA in excess have been linked to CHD risk. We cannot consider all SFA as a block. The effects of reducing SFA intakes depend on which nutrients replace them and on which biomarkers or endpoints are assessed, Ronald Mensink observed. The effects of reducing SFA on CHD risk vary with the nutrient of comparison, whether carbohydrates, monounsaturated or polyunsaturated fatty acids. Substitution of SFA with polyunsaturated fatty acids was associated with a lower incidence of cardiovascular disease, while the effects of substitution with monounsaturated fatty acids or high-glycemic index carbohydrates are less clear.

Association between habitual dietary intake and lipoprotein subclass profile in healthy young adults

BACKGROUND AND AIMS

Nutritional epidemiology is increasingly shifting its focus from studying single nutrients to the exploration of the whole diet utilizing dietary pattern analysis. We analyzed associations between habitual diet (including macronutrients, dietary patterns, biomarker of fish intake) and lipoprotein particle subclass profile in young adults.

METHODS AND RESULTS

Complete dietary data (food-frequency questionnaire) and lipoprotein subclass profile (via nuclear magnetic resonance spectroscopy) were available for 663 subjects from the population-based FinnTwin12 study (57% women, age: 21-25 y). The serum docosahexaenoic to total fatty acid ratio was used as a biomarker of habitual fish consumption. Factor analysis identified 5 dietary patterns: "Fruit and vegetables", "Meat", "Sweets and desserts", "Junk food" and "Fish". After adjustment for sex, age, body mass index, waist circumference, physical activity, smoking status and alcohol intake, the "Junk food" pattern was positively related to serum triglycerides (r = 0.12, P = 0.002), a shift in the subclass distribution of VLDL toward larger particles (r = 0.12 for VLDL size, P < 0.001) and LDL toward smaller particles (r = -0.15 for LDL size, P < 0.001). In addition, higher scores on this pattern were positively correlated with concentrations of small, dense HDL (r = 0.16, P < 0.001). Habitual fish intake associated negatively with VLDL particle diameter ("Fish" pattern and biomarker) and positively with HDL particle diameter (biomarker).

CONCLUSIONS

Our results suggest that in young adults, higher habitual fish consumption is related to favorable subclass distributions of VLDL and HDL, while junk food intake is associated with unfavorable alterations in the distribution of all lipoprotein subclasses independent of adiposity and other lifestyle factors.

Associations between smoking, components of metabolic syndrome and lipoprotein particle size

BACKGROUND

The clustering of metabolic and cardiovascular risk factors is known as metabolic syndrome (MetS). The risk of having MetS is strongly associated with increased adiposity and can be further modified by smoking behavior. Apolipoproteins (apo) associated with low-density lipoprotein-cholesterol (LDL-C) and high-density lipoprotein-cholesterol (HDL-C) may be altered in MetS. This study aimed to examine the association between smoking and the following parameters: MetS and its components, levels of apolipoproteins and estimated lipoprotein particle size, separately for men and women, and in different body mass index (BMI) classes.

METHODS

We included 24,389 men and 35,078 women aged between 18 and 80 years who participated in the LifeLines Cohort Study between December 2006 and January 2012; 5,685 men and 6,989 women were current smokers. Participants were categorized into three different body mass index (BMI) classes (BMI <25; BMI 25 to 30; BMI ≥30 kg/m²). MetS was defined according to the National Cholesterol Education Program's Adult Treatment Panel III (NCEP:ATPIII) criteria. Blood pressure, anthropometric and lipid measurements were rigorously standardized, and the large sample size enabled a powerful estimate of quantitative changes. The association between smoking and the individual MetS components, and apoA1 and apoB, was tested with linear regression. Logistic regression was used to examine the effect of smoking and daily tobacco smoked on risk of having MetS. All models were age adjusted and stratified by sex and BMI class.

RESULTS

Prevalence of MetS increased with higher BMI levels. A total of 64% of obese men and 42% of obese women had MetS. Current smoking was associated with a higher risk of MetS in both sexes and all BMI classes (odds ratio 1.7 to 2.4 for men, 1.8 to 2.3 for women, all P values <0.001). Current smokers had lower levels of HDL cholesterol and apoA1, higher levels of triglycerides and apoB, and higher waist circumference than non-smokers (all P <0.001). Smoking had no consistent association with blood pressure or fasting blood glucose. In all BMI classes, we found a dose-dependent association of daily tobacco consumption with MetS prevalence as well as with lower levels of HDL cholesterol, higher triglyceride levels and lower ratios of HDL cholesterol/apoA1 and, only in those with BMI <30, LDL cholesterol/apoB (all P <0.001).

CONCLUSIONS

Smoking is associated with an increased prevalence of MetS, independent of sex and BMI class. This increased risk is mainly related to lower HDL cholesterol, and higher triglycerides and waist circumference. In addition, smoking was associated with unfavorable changes in apoA1 and apoB, and in lipoprotein particle size. Please see related commentary: http://www.biomedcentral.com/1741-7015/11/196.

Associations of erythrocyte fatty acids in the de novo lipogenesis pathway with risk of metabolic syndrome in a cohort study of middle-aged and older Chinese

BACKGROUND

Experimental studies suggest that elevated de novo lipogenesis (DNL) might be involved in the pathogenesis of metabolic disorders. Few prospective studies have been conducted, especially among populations with a high carbohydrate intake, to determine whether DNL fatty acids are associated with the risk of the metabolic syndrome (MetS).

OBJECTIVE

We aimed to investigate associations of erythrocyte fatty acids in the DNL pathway-including myristic acid (14:0), palmitic acid (16:0), palmitoleic acid (16:1n-7), hexadecenoic acid (16:1n-9), stearic acid (18:0), vaccenic acid (18:1n-7), and oleic acid (18:1n-9)-with the risk of MetS in a Chinese population with an average carbohydrate intake of >60% of energy.

DESIGN

A total of 1176 free-living Chinese men and women aged 50-70 y from Beijing and Shanghai were included in our analysis, giving rise to 412 incident MetS cases during 6 y of follow-up. Erythrocyte fatty acids and metabolic traits were measured in these participants.

RESULTS

Erythrocyte fatty acids in the DNL pathway were correlated with a high ratio of carbohydrate-to-fat intake, less favorable lipid profiles, and elevated liver enzymes at baseline. In comparison with the lowest quartile, RRs (95% CIs) of MetS in the highest quartile were 1.30 (1.04, 1.62; P-trend = 0.007) for 16:1n-7, 1.48 (1.17, 1.86; P-trend < 0.001) for 16:1n-9, 1.26 (1.01, 1.56; P-trend = 0.06) for 18:1n-7, and 1.51 (1.19, 1.92; P-trend < 0.001) for 18:1n-9 after multivariate adjustment for lifestyle factors and body mass index. Moreover, 16:0 and 16:1n-7 were associated with an elevated risk of diabetes.

CONCLUSION

Our findings suggest that fatty acids in the DNL pathway are independently associated with an elevated risk of metabolic disorders.

High-density lipoprotein subclasses and risk of stroke and its subtypes in Japanese population: the Circulatory Risk in Communities Study

BACKGROUND AND PURPOSE

High-density lipoprotein (HDL) cholesterol is an established protective factor for ischemic stroke. However, the contribution of HDL subclasses to stroke risk and its subtypes is uncertain.

METHODS

A prospective nested case-control study of 40- to 85-year-old Japanese was undertaken using frozen serum samples collected from 5280 men and 7524 women. They participated in cardiovascular risk surveys from 1985 to 1999 (1 community) and 1989 to 1998 (2 communities) under Circulatory Risk in Communities Study. HDL cholesterol subclasses were classified by high-performance liquid chromatography into 3 subgroups: S-HDL (very small or small HDL), M-HDL (medium HDL), and L-HDL (large or very large HDL) cholesterol. One control subject per case was matched by sex, age, community, serum storage year, and fasting status.

RESULTS

In 2005, we identified 241 strokes (155 ischemic and 86 hemorrhagic). S-HDL and M-HDL cholesterol levels were inversely associated with total stroke risk, ischemic stroke, specifically lacunar infarction, and hemorrhagic stroke. After adjustment for cardiovascular risk factors, these associations remained statistically significant. Multivariable conditional odds ratios (95% confidence interval) for 1 SD (0.12 mmol/L) increment of S-HDL cholesterol levels were 0.34 (0.23-0.52) for total stroke, 0.38 (0.23-0.63) for ischemic stroke, 0.33 (0.18-0.61) for lacunar infarction, 0.30 (0.14-0.65) for hemorrhagic stroke, and 0.30 (0.12-0.77) for intraparenchymal hemorrhage. The respective multivariable odds ratios for 1SD (0.10 mmol/L) increment of M-HDL cholesterol levels were 0.56 (0.41-0.75), 0.63 (0.45-0.88), 0.59 (0.40-0.87), 0.41 (0.21-0.80), and 0.38 (0.16-0.90). No associations were found between L-HDL cholesterol levels and risk of total stroke and its subtypes.

CONCLUSIONS

Small- to medium-sized HDL, not large HDL, cholesterol levels were inversely associated with total stroke risk.

Lipoprotein subfractions and dietary intake of n-3 fatty acid: the Genetics of Coronary Artery Disease in Alaska Natives study

BACKGROUND

Few studies have compared lipoprotein composition with dietary intake.

OBJECTIVE

The lipoprotein subfraction profile was evaluated in relation to diet in Alaska Eskimos at high cardiovascular risk but with a low frequency of hyperlipidemia and high intake of n-3 (omega-3) fatty acids.

DESIGN

A population-based sample (n = 1214) from the Norton Sound Region of Alaska underwent a physical examination and blood sampling. Analyses were from 977 individuals who did not have diabetes or use lipid-lowering medications and had complete dietary information (food-frequency questionnaire) and a lipoprotein subfraction profile (nuclear magnetic resonance spectroscopy).

RESULTS

After adjustment for age, BMI, total energy intake, and percentage of energy from fat, the intake of n-3 fatty acids was significantly associated with fewer large VLDLs (P = 0.022 in women, P = 0.064 in men), a smaller VLDL size (P = 0.018 and P = 0.036), more large HDLs (P = 0.179 and P = 0.021), and a larger HDL size (P = 0.004 and P = 0.001). After adjustment for carbohydrate and sugar intakes, large VLDLs (P = 0.042 and 0.018) and VLDL size (P = 0.011 and 0.025) remained negatively associated with n-3 fatty acid intake in women and men, and large HDLs (P = 0.067 and 0.005) and HDL size (P = 0.001 in both) remained positively associated with n-3 fatty acid intake in women and men. In addition, large LDLs (P = 0.040 and P = 0.025) were positively associated in both sexes, and LDL size (P = 0.006) showed a positive association in women. There were no significant relations with total LDL particles in either model.

CONCLUSIONS

Dietary n-3 fatty acids, independent of the reciprocal changes in carbohydrate and sugar intakes, are associated with an overall favorable lipoprotein profile in terms of cardiovascular risk. Because there are no relations with total LDL particles, the benefit may be related to cardiovascular processes other than atherosclerosis.

Dietary fatty acid composition and metabolic syndrome in Tehranian adults

OBJECTIVE

Several studies have shown that dietary and plasma fatty acid (FA) composition can modulate the development of metabolic syndrome, but epidemiologic data are scarce. The aim of this study was to evaluate the association between dietary FA composition and metabolic syndrome in Tehranian adults.

METHODS

Dietary FA composition and symptoms of metabolic syndrome were assessed in a population-based cross-sectional study of 822 participants (354 men and 468 women, 18-74 y old) as part of the Tehran Lipid and Glucose Study. Metabolic syndrome was defined according to the guidelines presented by the Adult Treatment Panel III.

RESULTS

The means ± standard deviations for dietary FA composition of total fat, linoleic acid, oleic acid, and saturated FA were 30.3 ± 7.5%, 1.43 ± 1.76%, 2.87 ± 2.19%, and 5.7 ± 2.2% of daily consumed energy, respectively. No significant correlation between the percentage of linoleic or oleic acids and metabolic syndrome was observed. Participants whose consumption of saturated FA was in the highest quartile had a significantly increased probability of acquiring metabolic syndrome (odds ratios by quartile 1, 0.83, 0.91, 0.95, P for trend <0.03). The odds ratios decreased after adjusting for indicators of a healthy lifestyle, including diet.

CONCLUSION

The data from this study indicate that increased consumption of dietary total fat, especially saturated FA, is associated with a higher risk of metabolic syndrome in Tehranian adults. The relation, apparently, is influenced by an individual's lifestyle.

High disaccharide intake associates with atherogenic lipoprotein profile

Increased plasma concentrations of small LDL particles denote an atherogenic lipoprotein phenotype (ALP) that is correlated with increased circulating TAG and reduced HDL-cholesterol. Principal component analyses of subfraction concentrations have previously been used in the Swedish population-based Malmö Diet and Cancer (MDC) cohort to identify three independent components, one pattern representing the ALP. The aim of the present study was to examine the associations between macronutrient intakes and the principal component representing the ALP. We examined 4301 healthy subjects (46-68 years old, 60 % women) at baseline in the MDC cohort. Dietary data were collected using a modified diet history method. Plasma lipoprotein subfractions were measured using a high-resolution ion mobility method. The principal component corresponding to the ALP was significantly associated with a higher intake of disaccharides, and inversely related to protein and alcohol consumption (P < 0·001 for all). The present findings indicate that the ALP may be improved by a low intake of disaccharides, and moderate intakes of protein and alcohol.

ISSFAL 2010 dinner debate: healthy fats for healthy hearts - annotated report of a scientific discussion

BACKGROUND/AIMS

The importance of reducing saturated fatty acid intake to prevent cardiovascular disease and recommended intakes for omega-6 polyunsaturated fatty acids (PUFAs) are controversial. Therefore, experts debated these topics at the biennial meeting of the International Society for the Study of Fatty Acids and Lipids (ISSFAL), in May 2010.

METHODS

Debate transcripts, debaters' and discussants' reviews and literature citations were the basis of this report.

RESULTS

Participants agreed that saturates per se are not 'bad', but that dietary recommendations should emphasize the substitution of unsaturates for part of the saturates. Evidence supporting omega-6 PUFA intakes of 5 to 10% is mixed; some interpret the overall data from diverse studies as consistent with a reduction in the risk of cardiovascular mortality and events. Others assert that randomized controlled trial data suggest that higher intakes of omega-6 PUFAs are not associated with lower risk of heart disease, or may even increase it.

CONCLUSIONS

All agreed that a 5-year randomized controlled trial comparing the effects of historically low (2%) with currently high (7.5%) linoleic acid intakes on cardiac endpoints would address the knowledge gap about the effects of different omega-6 PUFA intakes on the risk of heart disease.

Revisiting dietary cholesterol recommendations: does the evidence support a limit of 300 mg/d?

The perceived association between dietary cholesterol (DC) and risk for coronary heart disease (CHD) has resulted in recommendations of no more than 300 mg/d for healthy persons in the United States. These dietary recommendations proposed in the 1960s had little scientific evidence other than the known association between saturated fat and cholesterol and animal studies where cholesterol was fed in amounts far exceeding normal intakes. In contrast, European countries, Asian countries, and Canada do not have an upper limit for DC. Further, current epidemiologic data have clearly demonstrated that increasing concentrations of DC are not correlated with increased risk for CHD. Clinical studies have shown that even if DC may increase plasma low-density lipoprotein (LDL) cholesterol in certain individuals (hyper-responders), this is always accompanied by increases in high-density lipoprotein (HDL) cholesterol, so the LDL/HDL cholesterol ratio is maintained. More importantly, DC reduces circulating levels of small, dense LDL particles, a well-defined risk factor for CHD. This article presents recent evidence from human studies documenting the lack of effect of DC on CHD risk, suggesting that guidelines for DC should be revisited.

Differences in lipoprotein particle subclass distribution for Japanese Americans in Hawaii and Japanese in Japan: the INTERLIPID study

BACKGROUND

Current data suggest that low density lipoprotein (LDL) and high density lipoprotein (HDL) subclass concentrations relate directly to the risk of coronary heart disease (CHD). Earlier Studies indicated that Japanese in Japan had lower rates of CHD than Japanese Americans in Hawaii. Rates of CHD appear to continue to be lower in Japan despite increasing cholesterol levels in Japan and decreasing CHD rates in the United States.

OBJECTIVE

To provide insight into CHD rate differences.

METHODS

Nuclear Magnetic Resonance (NMR) measurements of lipoprotein subclasses were used to assess lipoprotein particle concentration and size in samples from these two genetically similar populations in Japan and Hawaii.

RESULTS

Japanese Americans had significantly higher age- and risk factor- adjusted concentrations of lipoprotein particles implicated in atherogenesis, including large very low density lipoprotein (VLDL; P < 0.001), small LDL (P < 0.001), and small HDL (women, P < 0.001; men, P < 0.01), and significantly lower concentrations of large LDL (P < 0.001) and the putative cardio-protective large HDL (P < 0.05) than Japanese in Japan. Average age- and risk factor- adjusted LDL and HDL particle sizes were also significantly (P < 0.001) smaller in Japanese Americans. Adjustment for body mass index markedly reduced the differences in some lipoprotein measures, including total LDL and large HDL particle concentrations for both genders, total VLDL particle concentration for women, and large VLDL concentration and average HDL particle size for men.

CONCLUSIONS

Differences in lipoprotein subclass distributions and lifestyle factors such as body weight may contribute to differences in CHD incidence for Japanese in Japan and Japanese Americans.