Eggs and beyond: is dietary cholesterol no longer important?

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.

Genetic susceptibility, dietary cholesterol intake, and plasma cholesterol levels in a Chinese population

Accompanied with nutrition transition, non-HDL-C levels of individuals in Asian countries has increased rapidly, which has caused the global epicenter of nonoptimal cholesterol to shift from Western countries to Asian countries. Thus, it is critical to underline major genetic and dietary determinants. In the current study of 2,330 Chinese individuals, genetic risk scores (GRSs) were calculated for total cholesterol (TC; GRS_TC, 57 SNPs), LDL-C (GRS_LDL-C, 45 SNPs), and HDL-C (GRS_HDL-C, 65 SNPs) based on SNPs from the Global Lipid Genetics Consortium study. Cholesterol intake was estimated by a 74-item food-frequency questionnaire. Associations of dietary cholesterol intake with plasma TC and LDL-C strengthened across quartiles of the GRS_TC (effect sizes: -0.29, 0.34, 2.45, and 6.47; P _interaction = 0.002) and GRS_LDL-C (effect sizes: -1.35, 0.17, 5.45, and 6.07; P _interaction = 0.001), respectively. Similar interactions with non-HDL-C were observed between dietary cholesterol and GRS_TC (P _interaction = 0.001) and GRS_LDL-C (P _interaction = 0.004). The adverse effects of GRS_TC on TC (effect sizes across dietary cholesterol quartiles: 0.51, 0.82, 1.21, and 1.31; P _interaction = 0.023) and GRS_LDL-C on LDL-C (effect sizes across dietary cholesterol quartiles: 0.66, 0.52, 1.12, and 1.56; P _interaction = 0.020) were more profound in those having higher cholesterol intake compared with those with lower intake. Our findings suggest significant interactions between genetic susceptibility and dietary cholesterol intake on plasma cholesterol profiles in a Chinese population.

Association of eggs with dietary nutrient adequacy and cardiovascular risk factors in US adults

OBJECTIVE

Whole eggs are rich sources of several micronutrients. However, it is not well known how egg consumption contributes to overall nutrient adequacy and how it may relate to CVD risk factors. Therefore, the present study aimed to determine how whole egg consumption contributes to nutrient intakes and to assess its association with CVD risk factors in US adults.

DESIGN

Cross-sectional study.

SETTING

The study was conducted using data from the National Health and Nutrition Examination Survey (NHANES) 2003-2012, a nationally representative survey of the US civilian population.ParticipantsAdults who completed two dietary recalls and provided information on relevant sociodemographic factors were included in the study (n 21 845).

RESULTS

Approximately 73 % of adults were classified as whole egg consumers. Egg consumption was associated with greater intakes of protein, saturated fat, mono- and polyunsaturated fats, Fe, Zn, Ca, Se, choline, and several other vitamins and minerals. Egg consumption was associated with a higher likelihood of meeting or exceeding recommendations for several micronutrients. Egg intake was positively associated with dietary cholesterol consumption, but not with serum total cholesterol (TC) when adjusted for multiple potential confounders. In multiple linear regression analyses, TAG, TAG:HDL-cholesterol and TC:HDL-cholesterol were significantly lower with greater egg consumption. Egg consumption had no significant relationship with LDL-cholesterol or C-reactive protein, but was associated with higher BMI and waist circumference.

CONCLUSIONS

Whole eggs are important dietary contributors of many nutrients and had either beneficial or non-significant associations with most CVD risk biomarkers examined.

Investigating the Role of Communication for Information Seekers' Trust-Related Evaluations of Health Videos on the Web: Content Analysis, Survey Data, and Experiment

Background

According to the language expectancy theory and the communication accommodation theory, health information seekers’ trust evaluations of Web-based videos are determined by interplays between content and seekers’ expectations on vloggers’ appropriate language use in specific contexts of Web-based communication.

Objectives

Two investigations focused on differences both between vloggers’ language styles and between users’ general trust in specific Web-based platforms to investigate how the context of Web-based communication can be characterized (research question, RQ1). Thereafter, we investigated whether information uncertainty, vloggers’ language style, and context of Web-based communication affect seekers’ trust evaluations of videos (RQ2).

Methods

With a content analysis of 36 health videos from YouTube and Vimeo, we examined the extent of trust-related linguistic characteristics (ie, first-person and second-person pronouns). Additionally, we surveyed participants (n=151) on their trust in YouTube and Moodle (academic Web-based platform; RQ1). In an experiment, further participants (n=124) watched a video about nutrition myths and were asked to evaluate the information credibility, vloggers’ trustworthiness, and accommodation of language by vloggers (RQ2). Following a 3 × 2 × 2 mixed design, vloggers’ explanations contained unambiguous (confirming or disconfirming) or ambiguous (neither confirming nor disconfirming) evidence on the myths (within factor). Furthermore, vloggers used YouTube-typical language (many first-person pronouns) or formal language (no first-person pronouns), and videos were presented on YouTube or Moodle (between factors).

Results

The content analysis revealed that videos on YouTube contained more first-person pronouns than on Vimeo (F_1,35=4.64; P=.04; η_p²=0.12), but no more second-person pronouns (F_1,35=1.23; P=.23). Furthermore, when asked about their trust in YouTube or Moodle, participants trusted YouTube more than Moodle (t₁₅₀≤−9.63; all P ≤.001). In the experiment, participants evaluated information to be more credible when information contained unambiguous rather than ambiguous evidence (F_2,116=9.109; P<.001; η_p²=0.14). Unexpectedly, information credibility did not depend on vloggers’ language style or the video platform (F_1,117≤2.40; P ≥.06). Likewise, video’s platform did not affect participants’ evaluations of vloggers’trustworthiness (F_1,117<0.18; P>.34). However, participants judged vloggers who used a YouTube-typical language as being more benevolent, and their language use as being more appropriate in both video platforms (F_1,117≥3.41; P ≤.03; η_p²≥0.028). Moreover, participants rated the YouTube-typical (vs formal) language as more appropriate for Moodle, but they did not rate one or the other language style as more appropriate for YouTube (F_1,117=5.40; P=.01; η_p²=0.04).

Conclusions

This study shows that among specific Web-based contexts, users’ typical language use can differ, as can their trust-related evaluations. In addition, health information seekers seem to be affected by providers’ language styles in ways that depend on the Web-based communication context. Accordingly, further investigations that would identify concrete interplays between language style and communication context might help providers to understand whether additional information would help or hurt seekers’ ability to accurately evaluate information.

7-Dehydrocholesterol (7-DHC), But Not Cholesterol, Causes Suppression of Canonical TGF-β Signaling and Is Likely Involved in the Development of Atherosclerotic Cardiovascular Disease (ASCVD)

For several decades, cholesterol has been thought to cause ASCVD. Limiting dietary cholesterol intake has been recommended to reduce the risk of the disease. However, several recent epidemiological studies do not support a relationship between dietary cholesterol and/or blood cholesterol and ASCVD. Consequently, the role of cholesterol in atherogenesis is now uncertain. Much evidence indicates that TGF-β, an anti-inflammatory cytokine, protects against ASCVD and that suppression of canonical TGF-β signaling (Smad2-dependent) is involved in atherogenesis. We had hypothesized that cholesterol causes ASCVD by suppressing canonical TGF-β signaling in vascular endothelium. To test this hypothesis, we determine the effects of cholesterol, 7-dehydrocholesterol (7-DHC; the biosynthetic precursor of cholesterol), and other sterols on canonical TGF-β signaling. We use Mv1Lu cells (a model cell system for studying TGF-β activity) stably expressing the Smad2-dependent luciferase reporter gene. We demonstrate that 7-DHC (but not cholesterol or other sterols) effectively suppresses the TGF-β-stimulated luciferase activity. We also demonstrate that 7-DHC suppresses TGF-β-stimulated luciferase activity by promoting lipid raft/caveolae formation and subsequently recruiting cell-surface TGF-β receptors from non-lipid raft microdomains to lipid rafts/caveolae where TGF-β receptors become inactive in transducing canonical signaling and undergo rapid degradation upon TGF-β binding. We determine this by cell-surface 125 I-TGF-β-cross-linking and sucrose density gradient ultracentrifugation. We further demonstrate that methyl-β-cyclodextrin (MβCD), a sterol-chelating agent, reverses 7-DHC-induced suppression of TGF-β-stimulated luciferase activity by extrusion of 7-DHC from resident lipid rafts/caveolae. These results suggest that 7-DHC, but not cholesterol, promotes lipid raft/caveolae formation, leading to suppression of canonical TGF-β signaling and atherogenesis. J. Cell. Biochem. 118: 1387-1400, 2017. © 2016 Wiley Periodicals, Inc.

Nutrition Interventions for Cardiovascular Disease

Nutrition therapy is effective at controlling cardiovascular disease risk factors and therefore reducing cardiovascular disease risk. Physicians should play an active role in providing nutrition interventions for patients who would benefit from cardiovascular disease risk reduction or refer them to other professionals as needed. The evidence on nutrition interventions for blood pressure and lipid control, including overall dietary patterns, dietary fat and macronutrients, dietary cholesterol, sodium, and alcohol intake, is discussed.

Eggs: good or bad?

Eggs have one of the lowest energy to nutrient density ratios of any food, and contain a quality of protein that is superior to beef steak and similar to dairy. From a nutritional perspective, this must qualify eggs as 'good'. The greater burden of proof has been to establish that eggs are not 'bad', by increasing awareness of the difference between dietary and blood cholesterol, and accumulating sufficient evidence to exonerate eggs from their associations with CVD and diabetes. After 60 years of research, a general consensus has now been reached that dietary cholesterol, chiefly from eggs, exerts a relatively small effect on serum LDL-cholesterol and CVD risk, in comparison with other diet and lifestyle factors. While dietary guidelines have been revised worldwide to reflect this view, associations between egg intake and the incidence of diabetes, and increased CVD risk in diabetes, prevail. These associations may be explained, in part, by residual confounding produced by other dietary components. The strength of evidence that links egg intake to increased CVD risk in diabetes is also complicated by variation in the response of serum LDL-cholesterol to eggs and dietary cholesterol in types 1 and 2 diabetes. On balance, the answer to the question as to whether eggs are 'bad', is probably 'no', but we do need to gain a better understanding of the effects of dietary cholesterol and its association with CVD risk in diabetes.