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Eggs and beyond: Is dietary cholesterol no longer important?

Eggs and beyond: is dietary cholesterol no longer important?
Robert H Eckel*
Divisions of Endocrinology, Metabolism, and Diabetes and Cardiology, University of Colorado School of Medicine, University of Colorado, Aurora, CO
Within the past 18 mo, 2 sets of nutritional guidelines, the 2013
American College of Cardiology/American Heart Association Life-
style Guideline for the Reduction of Cardiovascular Disease (1) and
the 2015 USDA Dietary Guidelines for Americans (http://www., have indicated that the ev-
idence for dietary cholesterol restriction to lower total and LDL
cholesterol is insufficient. In fact, the USDA guidelines state that
“cholesterol is not considered a nutrient of concern for overcon-
sumption.” These statements about dietary cholesterol have pro-
voked considerable reaction.
Related news coverage has been filled with mixed messages,
many of which have been and continue to be misinterpreted. On
10 February 2015, a Washington Post headline stated, “The U.S.
government is poised to withdraw longstanding warnings about
cholesterol.” CNN went on to report on 19 February 2015 that
“Cholesterol in Food Not a Concern, New Report Says.” And
although the 10 June 2015 issue of the Health Hub from the
Cleveland Clinic posed “Do Your Cholesterol Numbers Really
Matter?” they went on to say “yes—just because the emphasis on
cholesterol in food is less—it does not mean that your blood
cholesterol does not matter.” Nevertheless, can the public or even
the health care professional distinguish between the relative dis-
tinction and importance between dietary cholesterol and saturated
or even trans fat? In fact, confusion lies in the fact that ;60%
of cholesterol intake is from foods that also contain a moderate
amount of saturated fat such as beef/beef dishes, burgers, sausage,
bacon, and cheese, with the other ;40% mostly from eggs (;25%
of total cholesterol intake), chicken and chicken dishes (;12%),
and foods such as shellfish, which contain very little or a much
smaller percentage of total fat as saturated fat (http://appliedresearch.
Studies to document the independent effect of dietary cholesterol
on total serum cholesterol and LDL cholesterol have suffered from
methodologic flaws, including the absence of data that distinguish
the distribution of cholesterol among lipoprotein fractions, the use
of extreme ranges of cholesterol intake, and identifying subgroups
post hoc that respond differentially (2–4). Yet, a few very well-done
studies that support this independent effect of dietary cholesterol are
worth noting. In 1982, Schonfeld et al. (5) examined the impact of
750 compared with 1500 mg dietary cholesterol daily consumed in
the form of eggs on plasma lipoproteins in 20 young men in the
setting of diets with a range of polyunsaturated to saturated fat ratios
of 0.25, 0.4, 0.8, or 2.5. The addition of 750 mg cholesterol/
d to the diet with a P:S of 0.25–0.4 increased LDL cholesterol by 16
614 mg/dL, whereas the addition of 1500 mg increased LDL
cholesterol by 25 619 mg/dL (both P,0.01). When consumed
in the diet with a P:S of 0.8, only 1500 mg cholesterol/d increased
LDL cholesterol by17 622 mg/dL (P,0.02), whereas with the
diet with a P:S of 2.5, neither amount of cholesterol intake pro-
duced significant changes in LDL cholesterol. Thus, both the
cholesterol content and P:S of diets were important in determin-
ing LDL-cholesterol concentrations. In the mid-1990s, Ginsberg
et al. (6) studied healthy young men using a randomized, 4-way
crossover design to examine the impact of 0, 1, 2, or 4 eggs/d for
8 wk, with a daily cholesterol intake ranging from 128 to 858 mg,
on plasma lipids and lipoproteins, which were consumed while
following a step 1 American Heart Association diet. On average,
plasma total cholesterol increased by 1.5 mg/dL for every 100
mg dietary cholesterol added to the diet (P,0.001) and LDL
cholesterol increased in parallel. A similar study examined the
effects of the addition of 0, 1, or 3 eggs/d with dietary cholesterol
intakes ranging from 108 to 667 mg/d in healthy young women (7).
In the women, LDL cholesterol increased by 2.1 mg/dL per 100
mg dietary cholesterol/d (P¼0.003), which accounted for ;75%
of the increase in total cholesterol. HDL cholesterol also increased
by 0.57 mg/dL per 100 mg dietary cholesterol/d (P,0.04).
The meta-analysis by Berger et al. (8) published in this issue of the
Journal documents the heterogeneous nature of the clinical trials that
support a relation between dietary cholesterol and cardiovascular dis-
ease (CVD) risk. When extrapolating data shown in their Figure 3,
wherein subjects showed an increase in cholesterol intake from a mean
* To whom correspondence should be addressed. E-mail: robert.eckel@
Abbreviations used: CAD, coronary artery disease; CVD, cardiovascular
disease; P:S, ratio of polyunsaturated to saturated fat.
doi: 10.3945/ajcn.115.116905.
Am J Clin Nutr doi: 10.3945/ajcn.115.116905. Printed in USA. ÓAmerican Society for Nutrition 1of2
AJCN. First published ahead of print July 15, 2015 as doi: 10.3945/ajcn.115.116905.
Copyright (C) 2015 by the American Society for Nutrition
of 214 to 821 mg, or ;3 eggs daily, the mean increase in LDL
cholesterol was 7 mg/dL and in HDL cholesterol was ;3–4 mg/dL.
This increase in HDL cholesterol with increases in dietary choles-
terol is very similar to the effect of saturated fat on HDL cholesterol
and should not be inferred as neutralizing. In general, we live in an
age wherein increases in HDL cholesterol should be interpreted
cautiously in comparison to changes in LDL cholesterol (9).
Of interest without adequate documentation is the fact that the
decrease in coronary artery disease (CAD) incidence began after
recommendations for restrictions of total/saturated fat and dietary
cholesterol occurred (10) and before reductions in tobacco use and
risk factor modifications such as reductions in blood pressure and
LDL cholesterol with medications. Although the basis for ,300
or ,200 mg dietary cholesterol/d may have been questionable at
the time, this translated to ;1.5 or 1 egg/d in the absence of any
other dietary cholesterol intake. Because eggs remain the most
abundant source of dietary cholesterol and could be the most easily
assessed change in the low-fat, low-cholesterol diet, the decline
in egg consumption since 1945 ensued a bit earlier and paral-
leled CAD/stroke mortality since ;1950. Although such com-
parisons can be questioned for many reasons, the association is of
interest. Nevertheless, updated data show no consistent relation
between egg consumption and CVD (11).
Despite modest effects of dietary cholesterol on LDL cholesterol,
there is some evidence that patients with diabetes may be subject to
more harm. Most cholesterol absorption in the intestine is not from
the diet but from hepatobiliary sources (12). However, patients with
diabetes show increases in Niemann-Pick-like-1 protein, a molecule
that facilitates intestinal cholesterol transport, and microsomal
transfer protein, which couples triglycerides to apo B-48 dur-
ing chylomicron assembly; moreover, patients with diabetes show
reductions in the ATP-binding cassette gene (ABCG5G8) hetero-
dimer that promotes the re-excretion of enterocyte cholesterol
back into the intestinal lumen (13). Overall, these alterations
support increases in intestinal cholesterol absorption in patients
with diabetes. Although some studies indicate that more egg con-
sumption in patients with diabetes results in more CAD events (11,
14, 15), this relation has been questioned (16). Moreover, in a ran-
domized controlled 3-mo trial of 2 eggs/d for 6 d/wk in patients with
type 2 diabetes there was no adverse effect on lipid profile when the
diet included a higher content of MUFAs and PUFAs (17). Of in-
terest, however, are the results from the recent IMProved Reduction
of Outcomes: Vytorin Efficacy International Trial, which showed in
patients with diabetes a particularly pronounced beneficial effect of
ezetimibe (a drug that inhibits intestinal absorption of cholesterol) 1
simvastatin compared with simvastatin alone on CVD events (18).
Overall, some reservation is appropriate when claiming that di-
etary cholesterol is unimportant in modifying LDL cholesterol and
the risk of CVD. Yet, the primary emphasis should be placed on
dietary patterns wherein the overall diet is heart healthy (1), a set-
ting in which more egg consumption is likely not harmful. De-
spite .50 y of science, a few better-done crossover studies to
address the independent effect of dietary cholesterol in the setting
of a heart-healthy lifestyle would be timely, with or without statin
therapy on board. Nevertheless, when ordering an omelet, why
not order an egg white omelet with plenty of vegetables, lean meat,
and spices rather than one with 600 mg cholesterol?
The author had no personal or financial conflicts of interest related to this
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Baqleh K, Williams KH, Lau NS, Markovic TP. The effect of a high-
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... Recommendations to reduce the risk of ASCVD in humans include maintaining low cholesterol intake and low plasma cholesterol levels. However, in the last few years, there have been a number of epidemiological studies that do not support a relationship between dietary cholesterol and/or blood cholesterol and ASCVD [Kanter et al., 2012;Berger et al., 2015;Eckel, 2015]. This led to the 2015 USDA guidelines indicating that cholesterol is not a nutrient of concern for overconsumption. ...
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Transforming growth factor-β (TGF-β) responsiveness in cultured cells can be modulated by TGF-β partitioning between lipid raft/caveolae- and clathrin-mediated endocytosis pathways. The TbR-II/TbR-I binding ratio of TGF-β on the cell surface has recently been found to be a signal that controls TGF-β partitioning between these pathways. Since cholesterol is a structural component in lipid rafts/caveolae, we have studied the effects of cholesterol on TGF-β binding to TGF-β receptors and TGF-β responsiveness in cultured cells and in animals. Here we demonstrate that treatment with cholesterol, alone or complexed in lipoproteins, decreases the TbR-II/TbR-I binding ratio of TGF-β while treatment with cholesterol-lowering or cholesterol-depleting agents increases the TbR-II/TbR-I binding ratio of TGF-β in all cell types studied. Among cholesterol derivatives and analogs examined, cholesterol is the most potent agent for decreasing the TbR-II/TbR-I binding ratio of TGF-β. Cholesterol treatment increases accumulation of the TGF-β receptors in lipid rafts/caveolae as determined by sucrose density gradient ultracentrifugation analysis of cell lysates. Cholesterol/LDL suppresses TGF-β responsiveness and statins/β-CD enhances it, as measured by the levels of P-Smad2 and PAI-1 expression in cells stimulated with TGF-β. Furthermore, the cholesterol effects observed in cultured cells are also found in the aortic endothelium of atherosclerotic ApoE-null mice fed a high cholesterol diet. These results indicate that high plasma cholesterol levels may contribute to the pathogenesis of certain diseases (e.g., atherosclerosis) by suppressing TGF-β responsiveness.
... The safety theory on cholesterol is, therefore, not broad-certified, and judgment varies among the commentators concerned. An expert engaged in the field of egg production has reported that eggs are no longer unsafe [10], while a doctor insists that a report that cholesterol intake does not have a serious influence on low density lipoprotein (LDL)cholesterol, the risk of cardiovascular disease (CVD) should be considered conditional, and it is appropriate to refrain from egg consumption [11]. A researcher in the nutrition field has stated that to be fair, the answer to the question as to whether eggs are bad is probably, "no" [12]. ...
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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.
... That analysis showed that dietary cholesterol was not associated with increased risk of incident CVD, yet it statistically significantly increased serum total cholesterol (TC), LDL-C and the ratio of LDL-C to HDL-cholesterol (HDL-C). Importantly, results across studies in the meta-analysis were heterogeneous, and experts have suggested that adopting healthy dietary patterns should be emphasized over simply adhering to dietary cholesterol limits (6) . ...
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. Participants Adults 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.
... All nutrition myths (in each video presented in this order: coffee and dementia, cola and pretzel sticks, too many diet beverages leading to diabetes, the healthiness of low salt diet, harmfulness of too many eggs, healthy nutrition and cancer) resulted from Web-based searches for frequent and typical nutrition myths in online forums. Although all explanations reflect the current scientific findings about related topics [110][111][112][113][114][115][116], explanations summarized the scientific evidence as if it speaks for, against, or neither for nor against the nutrition myths. ...
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see a pre-print version of the manuscript (accepted in i-JMR) BACKGROUND: Online, health information seekers need to identify criteria that indicate who and what information they can rely on. According to Language Expectancy Theory (LET) and Communication Accommodation Theory (CAT), the communicative success of seeking health information online is not only determined by the content per se but is also determined by a reciprocal interplay among the content, information providers' language styles, and the context of online communication. Accordingly, information seekers' trust-related evaluations should also be impacted by their expectations on appropriate language use given a specific context of communication, whereby we define context of online communication as it refers to the concept of context in LET and CAT and includes users' use of online media. OBJECTIVE: In particular, the article aims to investigate whether information providers' language styles and the context of online communication affect how people judge health-related online information. Thus, first we aimed to investigate differences both between users' language styles on online platforms and between users' general trust in specific online platforms (ie, platforms that are used for viewing online health videos) to identify aspects that differ among online contexts (RQ1). Then, we investigated whether health information seekers evaluate information differently (related to if they trust it) depending (individually and reciprocally) on various factors - the uncertainty of online information, the language styles of information providers, and the context of online communication (RQ2). METHODS: To address RQ1, we conducted a content analysis of 36 health videos from YouTube and Vimeo and examined whether the extent of trust-related linguistic characteristics (ie, first-person and second-person pronouns) differs between videos on YouTube and Vimeo. Additionally, we examined participants' (n=151) trust in YouTube and Moodle (an academic online platform). To address RQ2, participants (n=124) took part in an online experiment and watched an online video about nutrition myths. Following a 3 x 2 x 2 mixed design, the vlogger's explanations contained either confirming, disconfirming, or neither confirming nor disconfirming evidence on the nutrition myths (within factor). Further, explanations were given either in YouTube-typical language (ie, containing many first-person pronouns) or in formal language (ie, no first-person pronouns) (between factor) and were presented on YouTube or Moodle (between factor). Participants evaluated the credibility of information, the trustworthiness of the vlogger, and the language accommodation by the vlogger. RESULTS: The content analysis of videos on YouTube and Vimeo revealed that YouTube contained more first-person pronouns than Vimeo (F(1, 35)=4.64, P=.04, ηp2 = 0.12), ), whereas the amount of second-person pronouns did not differ between both video platforms, F(1, 35)=1.23, P=.23. Further, when asked about their general trust in different platforms (YouTube vs. Moodle) participants trusted YouTube more than Moodle, all t(150)≤-9.63, P≤.001. For the mixed design experiment that tested how various factors influence health seekers' trust evaluations, we found that participants evaluated information to be more credible when it was definitive (when the information either confirmed or disconfirmed the nutrition myth) than when it was ambiguous (when it neither confirmed nor disconfirmed the myth), F(2, 116)=9.109, P<.001, ηp2=.136. Interestingly, the credibility of information did not change depending on the vlogger's language style or the online platform, both F(1,117)≤2.40, P≥.06. Similarly, the video's platform did not affect participants' evaluations of the vlogger's trustworthiness (F(1, 117)<.18, P>.34). However, participants' judgments of the vlogger's trustworthiness and of the language accommodation by the vlogger both individually depended on the vlogger's language style, both F(1, 117) ≥3.41, P≤.03, ηp2≥.028. That is, participants judged the vlogger who used a YouTube-typical language style as being more benevolent, and they judged her language use as being more appropriate for the audiences of both online platforms. Moreover, participants were reciprocally impacted by the online platforms and the vlogger's language styles, as they thought that the YouTube-typical (vs. formal) language style was more appropriate for Moodle, but they did not think that one or the other language style (YouTube-typical or formal) was more appropriate for YouTube, F(1, 117)=5.40, P=.01, ηp2=.04. CONCLUSIONS: Health information seekers and providers should consider the context of communication in online settings. Even though it is difficult to consider all the aspects that make up an online communication context, this work shows that among specific online contexts, users' typical language use can differ, as can their trust-related evaluations. Additionally, health information seekers seem to be affected by providers' language styles in ways that depend on the online communication context. Moreover, it seems worthwhile to further investigate how the uncertainty of presented health information affects seekers' trust-related evaluations if seekers' existing knowledge differs. Such studies might help information providers understand if providing additional information would help or hurt seekers' ability to accurately evaluate evidence, particularly ambiguous evidence.
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Most research on health interventions aims to find evidence to support better causal inferences about those interventions. However, for decades, a majority of this research has been criticised for inadequate control of bias and overconfident conclusions that do not reflect the uncertainty. Yet, despite the need for improvement, clear signs of progress have not appeared, suggesting the need for new ideas on ways to reduce bias and improve the quality of research. With the aim of understanding why bias has been difficult to reduce, we first explore the concepts of causal inference, bias and uncertainty as they relate to health intervention research. We propose a useful definition of ‘a causal inference’ as: ‘a conclusion that the evidence available supports either the existence, or the non-existence, of a causal effect’. We used this definition in a methodological review that compared the statistical methods used in health intervention cohort studies with the strength of causal language expressed in each study’s conclusions. Studies that used simple instead of multivariable methods, or did not conduct a sensitivity analysis, were more likely to contain overconfident conclusions and potentially mislead readers. The review also examined how the strength of causal language can be judged, including an attempt to create an automatic rating algorithm that we ultimately deemed cannot succeed. This review also found that a third of the articles (94/288) used a propensity score method, highlighting the popularity of a method developed specifically for causal inference. On the other hand, 11% of the articles did not adjust for any confounders, relying on methods such as t-tests and chi-squared tests. This suggests that many researchers still lack an understanding of how likely it is that confounding affects their results. Drawing on knowledge from statistics, philosophy, linguistics, cognitive psychology, and all areas of health research, the central importance of how people think and make decisions is examined in relation to bias in research. This reveals the many hard-wired cognitive biases that, aside from confirmation bias, are mostly unknown to statisticians and researchers in health. This is partly because they mostly occur without conscious awareness, yet everyone is susceptible. But while the existence of biases such as overconfidence bias, anchoring, and failure to account for the base rate have been raised in the health research literature, we examine biases that have not been raised in health, or we discuss them from a different perspective. This includes a tendency of people to accept the first explanation that comes to mind (called take-the-first heuristic); how we tend to believe that other people are more susceptible to cognitive biases than we are (bias blind spot); a tendency to seek arguments that defend our beliefs, rather than seeking the objective truth (myside bias); a bias for causal explanations (various names including the causality heuristic); and our desire to avoid cognitive effort (many names including the ‘law of least mental effort’). This knowledge and understanding also suggest methods that might counter these biases and improve the quality of research. This includes any technique that encourages the consideration of alternative explanations of the results. We provide novel arguments for a number of methods that might help, such as the deliberate listing of alternative explanations, but also some novel ideas including a form of adversarial collaboration. Another method that encourages the researcher to consider alternative explanations is causal diagrams. However, we introduce them in a way that differs from the more formal presentation that is currently the norm, avoiding most of the terminology to focus instead on their use as an intuitive framework, helping the researcher to understand the biases that may lead to different conclusions. We also present a case study where we analysed the data for a pragmatic randomised controlled trial of a telemonitoring service. Considerable missing data hampered the forming of conclusions; however, this enabled an exploration of methods to better understand, reduce and communicate the uncertainty that remained after the analysis. Methods used included multiple imputation, causal diagrams, a listing of alternative explanations, and the parametric g-formula to handle bias from time-dependent confounding. Finally, we suggest strategies, resources and tools that may overcome some of the barriers to better control of bias and improvements in causal inference, based on the knowledge and ideas presented in this thesis. This includes a proposed online searchable causal diagram database, to make causal diagrams themselves easier to learn and use.
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Accompanied with nutrition transition, non-HDL-cholesterol (HDL-C) levels of Asian countries increased rapidly, which has caused the global epicenter of non-optimal 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-cholesterol (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 on 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 to those with lower intake. Our findings suggest significant interactions between genetic susceptibility and dietary cholesterol intake on plasma cholesterol profiles in a Chinese population.
The evidence from epidemiological studies supports the conclusion that consumption of 1~2 eggs per day does not influence blood cholesterol levels in healthy individuals receiving the prudent eating pattern. However, the judgement is based on the presence of non-responder to dietary cholesterol at two-thirds of whole population. Attention is therefore necessary to the egg intake in people who are responsive to dietary cholesterol. There is no decisive evidence supporting the allowable limit of egg consumption for Japanese due to multiple confounding factors. In the association between egg and blood cholesterol we should thoroughly recognize an interpretation limit of the epidemiological studies and correspond from a nutritional viewpoint. In Japan the egg is one of the most important foods contributing to our healthy longevity, even though it is providing nearly half of our cholesterol intake.
Nutrition research, in contrast with randomized clinical trials that compare a drug with placebo, is more difficult for many reasons, including complexities in data gathering and changes in human behavior over time. In this issue of JAMA, Zhong and colleagues¹ report new insights about a controversial topic, the association of egg consumption and dietary cholesterol with cardiovascular disease (CVD) incidence and all-cause mortality. Clearly, the topic of this study is important to clinicians, patients, and the public at large because the association of egg consumption and dietary cholesterol with CVD, although debated for decades, has more recently been thought to be less important. Compared with the meta-analyses and reviews previously published, this report is far more comprehensive, with enough data to make a strong statement that eggs and overall dietary cholesterol intake remain important in affecting the risk of CVD and more so the risk of all-cause mortality.
This is a summary on the cumulative dissertation. Seeking health information online is a prevalent way to obtain knowledge about any medical issue, as it is low-thresholding, anonymous, and independent from medical appointments. In this sense, seeking online information also goes along with relevant decisions for people’s health. Thus, it is crucial to understand how people assess the accuracy of online information. Since health information seekers are usually incapable to assess the accuracy of information efficiently, they need to identify whom and which information to rely on. At the same time, the relationship between health information seekers and providers is mainly determined by their communicative patterns. Thus, the present dissertation examines providers’ language styles and the contexts of online communication and how both aspects impact people’s evaluations of providers and information. In particular, the dissertation investigates whether providers’ language styles and the context of online communication do not only individually but also reciprocally impact people’s evaluations, as a specific language style might be appropriate within a specific context of online communication. Accordingly, the first study focuses on the extent of medical technical jargon used by providers toward an audience of either medical professionals or laypersons in online health forums. Furthermore, the extent of self-reference used by providers in an online video was examined, and whether the context of video presentation impacts people’s evaluations. The context of video presentation was realized by YouTube’s sidebars that recommend similar or unrelated other videos (Study 2), or by the online platforms YouTube and Moodle (i.e., an academic online platform) (Study 3). Study 1 revealed that the extent of medical technical jargon and the type of online forums impacted participants’ evaluations individually and reciprocally. Participants evaluated providers in forums for medical professionals to be more trustworthy than in forums for laypersons. In addition, they judged providers who used a low instead of a high amount of medical technical jargon to be more trustworthy and ascribed to them more language adaption toward the audience. In addition, participants evaluated the information to be more credible when providers’ medical technical jargon was appropriate toward the intended audience of the online forum. The results of Study 2 and Study 3 revealed ambiguous findings regarding the individual impact of the extent of self-reference by providers, which once impacted and once did not impact participants’ evaluations of providers’ benevolence. Furthermore, both operationalized contexts (YouTube’s sidebars with similar or unrelated videos and YouTube or Moodle) did not individually impact participants’ evaluations of providers and information. However, the extent of self-reference by providers influenced participants’ evaluations of providers’ trustworthiness depending on YouTube’s sidebar (Study 2) as wells as their ascription of language accommodation depending on Moodle and YouTube (Study 3). In sum, the present dissertation gives insights into the role of an appropriate language use given specific online communication contexts. It shows that the consideration of both aspects is also crucial for seeking health information online. Future research should consider various aspects of contexts of online communication to expand the understanding of how people assess online health information. The results of the present dissertation likewise can inform health information seekers and providers.
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Dietary cholesterol has been suggested to increase the risk of cardiovascular disease (CVD), which has led to US recommendations to reduce cholesterol intake. The authors examine the effects of dietary cholesterol on CVD risk in healthy adults by using systematic review and meta-analysis. MEDLINE, Cochrane Central, and Commonwealth Agricultural Bureau Abstracts databases were searched through December 2013 for prospective studies that quantified dietary cholesterol. Investigators independently screened citations and verified extracted data on study and participant characteristics, outcomes, and quality. Random-effect models meta-analysis was used when at least 3 studies reported the same CVD outcome. Forty studies (17 cohorts in 19 publications with 361,923 subjects and 19 trials in 21 publications with 632 subjects) published between 1979 and 2013 were eligible for review. Dietary cholesterol was not statistically significantly associated with any coronary artery disease (4 cohorts; no summary RR), ischemic stroke (4 cohorts; summary RR: 1.13; 95% CI: 0.99, 1.28), or hemorrhagic stroke (3 cohorts; summary RR: 1.09; 95% CI: 0.79, 1.50). Dietary cholesterol statistically significantly increased both serum total cholesterol (17 trials; net change: 11.2 mg/dL; 95% CI: 6.4, 15.9) and low-density lipoprotein (LDL) cholesterol (14 trials; net change: 6.7 mg/dL; 95% CI: 1.7, 11.7). Increases in LDL cholesterol were no longer statistically significant when intervention doses exceeded 900 mg/d. Dietary cholesterol also statistically significantly increased serum high-density lipoprotein cholesterol (13 trials; net change: 3.2 mg/dL; 95% CI: 0.9, 9.7) and the LDL to high-density lipoprotein ratio (5 trials; net change: 0.2; 95% CI: 0.0, 0.3). Dietary cholesterol did not statistically significantly change serum triglycerides or very-low-density lipoprotein concentrations. Reviewed studies were heterogeneous and lacked the methodologic rigor to draw any conclusions regarding the effects of dietary cholesterol on CVD risk. Carefully adjusted and well-conducted cohort studies would be useful to identify the relative effects of dietary cholesterol on CVD risk. © 2015 American Society for Nutrition.
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Background: Statin therapy reduces low-density lipoprotein (LDL) cholesterol levels and the risk of cardiovascular events, but whether the addition of ezetimibe, a nonstatin drug that reduces intestinal cholesterol absorption, can reduce the rate of cardiovascular events further is not known. Methods: We conducted a double-blind, randomized trial involving 18,144 patients who had been hospitalized for an acute coronary syndrome within the preceding 10 days and had LDL cholesterol levels of 50 to 100 mg per deciliter (1.3 to 2.6 mmol per liter) if they were receiving lipid-lowering therapy or 50 to 125 mg per deciliter (1.3 to 3.2 mmol per liter) if they were not receiving lipid-lowering therapy. The combination of simvastatin (40 mg) and ezetimibe (10 mg) (simvastatin-ezetimibe) was compared with simvastatin (40 mg) and placebo (simvastatin monotherapy). The primary end point was a composite of cardiovascular death, nonfatal myocardial infarction, unstable angina requiring rehospitalization, coronary revascularization (≥30 days after randomization), or nonfatal stroke. The median follow-up was 6 years. Results: The median time-weighted average LDL cholesterol level during the study was 53.7 mg per deciliter (1.4 mmol per liter) in the simvastatin-ezetimibe group, as compared with 69.5 mg per deciliter (1.8 mmol per liter) in the simvastatin-monotherapy group (P<0.001). The Kaplan-Meier event rate for the primary end point at 7 years was 32.7% in the simvastatin-ezetimibe group, as compared with 34.7% in the simvastatin-monotherapy group (absolute risk difference, 2.0 percentage points; hazard ratio, 0.936; 95% confidence interval, 0.89 to 0.99; P=0.016). Rates of prespecified muscle, gallbladder, and hepatic adverse effects and cancer were similar in the two groups. Conclusions: When added to statin therapy, ezetimibe resulted in incremental lowering of LDL cholesterol levels and improved cardiovascular outcomes. Moreover, lowering LDL cholesterol to levels below previous targets provided additional benefit. (Funded by Merck; IMPROVE-IT number, NCT00202878.).
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In recent years, the high-density lipoprotein (HDL) hypothesis has been challenged. Several completed randomized clinical trials continue to fall short in demonstrating HDL, or at least HDL-cholesterol (HDL-C) levels, as being a consistent target in the prevention of cardiovascular diseases. However, population studies and findings in lipid modifying trials continue to strongly support HDL-C as a superb risk predictor. It is increasingly evident that the complexity of HDL metabolism confounds the use of HDL-C concentration as a unified target. However, important insights continue to emerge from the post hoc analyses of recently completed (i) fibrate-based FIELD and ACCORD trials, including the unexpected beneficial effect of fibrates in microvascular diseases, (ii) the niacin-based AIM-HIGH and HPS2-THRIVE studies, (iii) recombinant HDL-based as well as (iv) the completed CETP inhibitor-based trials. These together with on-going mechanistic studies on novel pathways, which include the unique roles of microRNAs, post-translational remodeling of HDL and novel pathways related to HDL modulators will provide valuable insights to guide how best to refocus and redesign the conceptual framework for selecting HDL-based targets.
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This study reviewed epidemiological and experimental evidence on the relationship between egg consumption and cardiovascular disease (CVD) risks among type II diabetes mellitus (T2DM) individuals, and T2DM risk in nondiabetic subjects. Four of the six studies that examined CVD and mortality and egg consumption among diabetics found a statistically significant association. Of the eight studies evaluating incident T2DM and egg consumption, four prospective studies found a statistically significant association. Lack of adjustment for dietary confounders was a common study limitation. A small number of experimental studies examined the relationship between egg intake and CVD risk biomarkers among diabetics or individuals with T2DM risk factors. Studies among healthy subjects found suggestive evidence that dietary interventions that include eggs may reduce the risk of T2DM and metabolic syndrome. Differences in study design, T2DM status, exposure measurement, subject age, control for confounders and follow-up time present significant challenges for conducting a meta-analysis. Conflicting results, coupled with small sample sizes, prevent broad interpretation. Given the study limitations, these findings need to be further investigated.
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Early work suggested that dietary cholesterol increased plasma total cholesterol concentrations in humans. Given the relationship between elevated plasma cholesterol concentrations and cardiovascular disease risk, dietary guidelines have consistently recommended limiting food sources of cholesterol. Current intakes are approaching recommended levels. Recently there have been calls to reassess the importance of continuing to recommend limiting dietary cholesterol. Over the past 10 years, there have been a limited number of studies addressing this issue. Striking among these studies is the high degree of variability in background diet, study subject characteristics, and study design. Within the context of current levels of dietary cholesterol intake, the effect on plasma lipid concentrations, with primary interest in LDL cholesterol concentrations, is modest and appears to be limited to population subgroups. In these cases, restrictions in dietary cholesterol intake are likely warranted. The biological determinants of interindividual variability remain a relatively understudied area.
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BACKGROUND: The associations of egg consumption with cardiovascular disease (CVD) and diabetes are still unclear. OBJECTIVE: We aimed to quantitatively summarize the literature on egg consumption and risk of CVD, cardiac mortality, and type 2 diabetes by conducting a meta-analysis of prospective cohort studies. DESIGN: A systematic literature review was conducted for published studies in PubMed and EMBASE through March 2012. Additional information was retrieved through Google or a hand review of the reference from relevant articles. Studies were included if they had a prospective study design, were published in English-language journals, and provided HRs and 95% CIs for the associations of interest. Data were independently extracted by 2 investigators, and the weighted HRs and 95% CIs for the associations of interest were estimated by using a random-effects model. RESULTS: A total of 22 independent cohorts from 16 studies were identified, including participants ranging in number from 1600 to 90,735 and in follow-up time from 5.8 to 20.0 y. Comparison of the highest category (≥1 egg/d) of egg consumption with the lowest (<1 egg/wk or never) resulted in a pooled HR (95% CI) of 0.96 (0.88, 1.05) for overall CVD, 0.97 (0.86, 1.09) for ischemic heart disease, 0.93 (0.81, 1.07) for stroke, 0.98 (0.77, 1.24) for ischemic heart disease mortality, 0.92 (0.56, 1.50) for stroke mortality, and 1.42 (1.09, 1.86) for type 2 diabetes. Of the studies conducted in diabetic patients, the pooled HR (95% CI) was 1.69 (1.09, 2.62) for overall CVD. CONCLUSION: This meta-analysis suggests that egg consumption is not associated with the risk of CVD and cardiac mortality in the general population. However, egg consumption may be associated with an increased incidence of type 2 diabetes among the general population and CVD comorbidity among diabetic patients.
Context Reduction in egg consumption has been widely recommended to lower blood cholesterol levels and prevent coronary heart disease (CHD). Epidemiologic studies on egg consumption and risk of CHD are sparse. Objective To examine the association between egg consumption and risk of CHD and stroke in men and women. Design and Setting Two prospective cohort studies, the Health Professionals Follow-up Study (1986-1994) and the Nurses' Health Study (1980-1994). Participants A total of 37,851 men aged 40 to 75 years at study outset and 80,082 women aged 34 to 59 years at study outset, free of cardiovascular disease, diabetes, hypercholesterolemia, or cancer. Main Outcome Measures Incident nonfatal myocardial infarction, fatal CHD, and stroke corresponding to daily egg consumption as determined by a food-frequency questionnaire. Results We documented 866 incident cases of CHD and 258 incident cases of stroke in men during 8 years of follow-up and 939 incident cases of CHD and 563 incident cases of stroke in women during 14 years of follow-up. After adjustment for age, smoking, and other potential CHD risk factors, we found no evidence of an overall significant association between egg consumption and risk of CHD or stroke in either men or women. The relative risks (RRs) of CHD across categories of intake were less than 1 per week (1.0), 1 per week (1.06), 2 to 4 per week (1.12), 5 to 6 per week (0.90), and ≥1 per day (1.08) (P for trend=.75) for men; and less than 1 per week (1.0), 1 per week (0.82), 2 to 4 per week (0.99), 5 to 6 per week (0.95), and ≥1 per day (0.82) (P for trend=.95) for women. In subgroup analyses, higher egg consumption appeared to be associated with increased risk of CHD only among diabetic subjects (RR of CHD comparing more than 1 egg per day with less than 1 egg per week among diabetic men, 2.02 [95% confidence interval, 1.05-3.87; P for trend=.04], and among diabetic women, 1.49 [0.88-2.52; P for trend=.008]). Conclusions These findings suggest that consumption of up to 1 egg per day is unlikely to have substantial overall impact on the risk of CHD or stroke among healthy men and women. The apparent increased risk of CHD associated with higher egg consumption among diabetic participants warrants further research.
Background: Previously published research that examined the effects of high egg consumption in people with type 2 diabetes (T2D) produced conflicting results leading to recommendations to limit egg intake. However, people with T2D may benefit from egg consumption because eggs are a nutritious and convenient way of improving protein and micronutrient contents of the diet, which have importance for satiety and weight management. Objective: In this randomized controlled study, we aimed to determine whether a high-egg diet (2 eggs/d for 6 d/wk) compared with a low-egg diet (<2 eggs/wk) affected circulating lipid profiles, in particular high-density lipoprotein (HDL) cholesterol, in overweight or obese people with prediabetes or T2D. Design: A total of 140 participants were randomly assigned to one of the 2 diets as part of a 3-mo weight maintenance study. Participants attended the clinic monthly and were instructed on the specific types of foods and quantities to be consumed. Results: There was no significant difference in the change in HDL cholesterol from screening to 3 mo between groups; the mean difference (95% CI) between high- and low-egg groups was +0.02 mmol/L (-0.03, 0.08 mmol/L; P = 0.38). No between-group differences were shown for total cholesterol, low-density lipoprotein cholesterol, triglycerides, or glycemic control. Both groups were matched for protein intake, but the high-egg group reported less hunger and greater satiety postbreakfast. Polyunsaturated fatty acid (PUFA) and monounsaturated fatty acid (MUFA) intakes significantly increased from baseline in both groups. Conclusions: High egg consumption did not have an adverse effect on the lipid profile of people with T2D in the context of increased MUFA and PUFA consumption. This study suggests that a high-egg diet can be included safely as part of the dietary management of T2D, and it may provide greater satiety. This trial was registered at the Australia New Zealand Clinical Trials Registry ( as ACTRN12612001266853.
Preamble and Transition to ACC/AHA Guidelines to The goals of the American College of Cardiology (ACC) and the American Heart Association (AHA) are to prevent cardiovascular diseases (CVDs); improve the management …