Association of dietary lipid intake with low-density lipoprotein cholesterol levels: analysis of two independent population-based studies

The Impact of Dietary Cholesterol on Low-Density Lipoprotein: Lessons in Absorption and Overconsumption

This case describes a 58-year-old woman with past medical history of ulcerative colitis, hyperlipidemia, and radiological evidence of atherosclerosis without prior cardiovascular disease who presented for management of hyperlipidemia. At baseline, her lipid panel in 2015 noted a calculated low-density lipoprotein (LDL-C) of 125 mg/dL (3.2 mmol/L). Over the course of the next 5 years, she developed severe LDL elevations to >400 mg/dL (>10.3 mmol/L) following the addition of 1600 mg dietary cholesterol daily achieved through 9 eggs. Following cessation of this intake she had dramatic improvements in LDL, which was later further augmented significantly by initiation of ezetimibe. The impact of dietary cholesterol on lipid profiles has long been an area of controversy, and, for the average American, current guidelines do not recommend egg restriction as an effective tool for LDL lowering. However, as highlighted in this case, certain individuals may be more prone to high LDL when consuming high cholesterol diets. Further study on how to better identify these susceptible individuals could help improve nutritional and medication treatment plans for patients with dyslipidemia.

Validation of the MSM and NCI Method for Estimating the Usual Intake of Nutrients and Food According to Four Seasons of Seven Consecutive Daily 24 Hour Dietary Recalls in Chinese Adults

The Multiple Source Method (MSM) and the National Cancer Institute (NCI) method are used to estimate usual dietary intake from short-term dietary assessment instruments, such as 24 hour dietary recall (24-HRs). However, their performance has not been validated in the Chinese population via nutrition surveys. To validate the accuracy of the MSM and NCI method in estimating usual dietary intake in the Chinese population, 752 individuals from northern and southern China answered four seasons of seven consecutive 24-HRs (one for each season). The true usual dietary intake was considered as the average of the 28 collection days of dietary component intake. Using data sets with consecutive 3 collection days, the usual intakes of the selected dietary components were estimated by MSM, NCI and the within-person mean of three 24-HRs (3 day method). These estimates were compared with the true usual intake at the group and individual level. At the group level, the MSM and NCI method performed similarly, yielding estimates closer to the true usual intake than 3 day method. The percentage differences of the estimates for dietary components not consumed daily from the MSM and NCI method were larger than for the dietary components consumed daily. However, the larger percentage differences were observed in the tail of the usual intake distribution. In general, dietary components with larger variance ratios had greater percentage differences. At the individual level, for overall seasons and dietary components, the biases of individual usual intake did agree for MSM and NCI method, whereas NCI method estimates were closer to true intakes than for the MSM and 3 day method. Similar results were observed in the relative biases of dietary components consumed daily. As with the group level, there was less percentage difference in dietary components consumed daily. Both the MSM and NCI method can be used to estimate usual intake in Chinese populations and are closer to the true usual intake than the traditional mean method, at both group and individual levels.

Alleviation of Dyslipidemia via a Traditional Balanced Korean Diet Represented by a Low Glycemic and Low Cholesterol Diet in Obese Women in a Randomized Controlled Trial

A traditional balanced Korean diet (K-diet) may improve energy, glucose, and lipid metabolism. To evaluate this, we conducted a randomized crossover clinical trial, involving participants aged 30–40 years, who were randomly assigned to two groups—a K-diet or westernized Korean control diet daily, with an estimated energy requirement (EER) of 1900 kcal. After a 4-week washout period, they switched the diet and followed it for 4 weeks. The carbohydrate, protein, and fat ratios based on energy intake were close to the target values for the K-diet (65:15:20) and control diet (60:15:25). The glycemic index of the control diet and the K-diet was 50.3 ± 3.6 and 68.1 ± 2.9, respectively, and daily cholesterol contents in the control diet and K-diet were 280 and 150 mg, respectively. Anthropometric and biochemical parameters involved in energy, glucose, and lipid metabolism were measured while plasma metabolites were determined using UPLC-QTOF-MS before and after the 4-week intervention. After the four-week intervention, both diets improved anthropometric and biochemical variables, but the K-diet significantly reduced them compared to the control diet. Serum total cholesterol, non-high-density lipoprotein cholesterol, and triglyceride concentrations were significantly lower in the K-diet group than in the control diet group. The waist circumference (p = 0.108) and insulin resistance index (QUICKI, p = 0.089) tended to be lower in the K-diet group than in the control diet group. Plasma metabolites indicated that participants in the K-diet group tended to reduce insulin resistance compared to those in the control diet group. Amino acids, especially branched-chain amino acids, tyrosine, tryptophan, and glutamate, and L-homocysteine concentrations were considerably lower in the K-diet group than in the control diet group (p < 0.05). Plasma glutathione concentrations, an index of antioxidant status, and 3-hydroxybutyric acid concentrations, were higher in the K-diet group than in the control diet group. In conclusion, a K-diet with adequate calories to meet EER alleviated dyslipidemia by decreasing insulin resistance-related amino acids and increasing ketones in the circulation of obese women.

Relationships between Maternal Dietary Patterns and Blood Lipid Levels during Pregnancy: A Prospective Cohort Study in Shanghai, China

The relationships between maternal dietary patterns and blood lipid profile during pregnancy have not been well understood. We aimed to analyze the dietary patterns of pregnant women and their associations with blood lipid concentrations during pregnancy. A cohort of 1008 Chinese pregnant women were followed from 10-15 weeks of gestation to delivery. Their dietary patterns were identified using a principal component analysis. The relationships between dietary pattern score and maternal blood lipid concentrations were assessed using both multivariate linear regression models and generalized estimating equation (GEE) models. Five different dietary patterns were identified. GEE showed that a high score for the fish-shrimps pattern was associated with higher concentrations of total cholesterol (TC) (β = 0.11), low-density lipoprotein cholesterol (LDL-C) (β = 0.07), and high-density lipoprotein cholesterol (HDL-C) (β = 0.03), with all p values < 0.001. In contrast, a high tubers-fruit-vegetables pattern score was associated with lower concentrations of TC (β = -0.12), LDL-C (β = -0.07), and HDL-C (β = -0.03), with all p values < 0.001. In addition, dietary protein, carbohydrate, and cholesterol intake significantly contributed to the associations between the fish-shrimps dietary pattern and blood lipid concentrations. Predominant seafood consumption is associated with higher cholesterol concentrations, whereas predominant tuber, fruit, and vegetable consumptions are associated with lower cholesterol concentrations during pregnancy.

Nutritional Viewpoints on Eggs and Cholesterol

Although most current epidemiologic studies indicate no significant association between consuming one egg daily and blood cholesterol levels and cardiovascular risk, arguments still persist with a positive association. Since the diet is one of the most influential factors for this association, we illustrate characteristic features in Japanese people whose dietary pattern is distinct from that, for example, the US (United States) population. Available epidemiologic studies in healthy Japanese people show no association between consumption of one egg daily and blood cholesterol level, consistent with those observed in the US population. However, when consumption of major nutrients and food sources of cholesterol are compared to the US population, Japanese people may have an extra-reserve against the influence of eggs on cardiovascular risk markers, despite consuming relatively more eggs. Further discussion on the influence of nutrients contained in the egg and dietary pattern, including interaction with gut microbes, is necessary. In addition, special consideration at the personalized level is needed for judgment regarding dietary cholesterol not only for hypercholesterolemic patients but for hyper-responsive healthy persons. Although randomized controlled trials with long-term follow-up are required to evaluate the association between consumption of eggs and human health, available information, at least from the nutritional viewpoint, suggests that egg is a healthy and cost-efficient food worldwide.

Lowering effects of fish oil supplementation on proinflammatory markers in hypertension: results from a randomized controlled trial

Reduced inflammation is one of the potential mechanisms underlying the cardioprotective efficacy of fish oil enriched with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Supplementation with fish oil has favorable effects on cardiometabolic profiles in Inner Mongolia patients with hypertension, but whether the cardiovascular benefits can be ascribed to reduced subclinical inflammation is unclear among this population. Seventy-seven middle-aged/elderly hypertensive volunteers were randomly assigned to receive either fish oil (FO, n = 38, 2 g day-1 EPA + DHA) or control corn oil (CO, n = 39) for 90 days. FA compositions in erythrocytes and C-reactive protein (CRP, mg L-1), interleukin-6 (IL-6, pg mL-1) and tumor necrosis factor-α (TNF-α, pg mL-1) concentrations in the plasma were measured before and after the 90-day supplementation, and the cardiometabolic risk was expressed as continuously distributed z-scores calculated by standardizing and then summing the individual cardiovascular risk factors. Significant reductions in the TNF-α (-1.87 ± 2.71 vs. -0.64 ± 2.62, p = 0.02) and CRP levels (-0.85 ± 2.49 vs. 0.56 ± 2.14, p = 0.01) were found in the FO group compared with the CO group, but not in the IL-6 levels (-0.66 ± 1.05 vs. -0.25 ± 0.94, p = 0.10). The decreases in the changes of TNF-α levels were positively correlated with the reductions in the cardiometabolic risk scores in the subjects supplemented with FO (r = 0.35, p = 0.02), but not in the control subjects supplemented with CO (r = 0.09, p = 0.54). FO supplementation increased the levels of EPA (p = 0.013), DHA (p = 0.040) and total n-3 FA (p = 0.035), and decreased the levels of 20:4n-6 (p = 0.041) and total n-6 FA (p = 0.011) and the ratio of n-6 to n-3 FA (p = 0.001), compared with the changes related to the CO group. The increases in the changes of erythrocyte total n-3 FA levels were inversely correlated with the concentrations of TNF-α (r = -0.34, p = 0.001) and CRP (r = -0.29, p = 0.020). The present findings suggest that fish oil supplementation may attenuate the proinflammatory reactions in hypertension, which might help promote the cardiometabolic benefits in this Inner Mongolia population.