Tag Archives: eggs

The Eggsoneration Continues: Why Does Anyone Eat Egg Whites?

The skeptical cardiologist pointed out in 2013 that there was no good evidence supporting limiting dietary cholesterol to 300 mg per day.  I exulted, therefore, in 2016 , when this long-standing dietary recommendation came out of the US dietary guidelines.

Recognizing that dietary cholesterol doesn’t need to be limited means that eggs and egg yolks are fine.

Egg Whites: A Product of Nutritional Misinformation?

Why, then do egg whites continue to be created and consumed?

On a regular basis, patients tell me that they are eating egg white omelettes because they believe egg yolks are not heart healthy.

Old bad nutritional dogma takes a long time to reverse apparently. To this day, for example, the National Lipid Association still recommends limiting daily cholesterol consumption to <200 mg/ day

Therefore I find it necessary to highlight additional new studies that further eggsonerate eggs.

To wit, I shall briefly discuss two articles that were published earlier this month and brought to my attention by friends and readers who are aware of my rabid support for the egg.

Article One: The Wonderfully Acronymed DIABEGG Study

Entitled  “Effect of a high-egg diet on cardiometabolic risk factors in people with type 2 diabetes: the Diabetes and Egg (DIABEGG) Study—randomized weight-loss and follow-up phase” our fist study was performed in Australia at the Sydney Medical School,

Investigators randomized 128 patients with prediabetes or type 2 diabetes (T2D) to a high egg or a low egg diet.

Throughout all study phases, including the 3-mo weight-loss phase, participants consuming the high-egg diet were instructed to eat 2 eggs/d at breakfast for 6 d/wk (12 eggs/wk). Those in the low-egg group were directed to consume <2 eggs/wk, and to match the protein intake that the high-egg group had consumed at breakfast with 10 g lean animal protein (meat, chicken, or sh) or other protein-rich alternatives, such as legumes and reduced-fat dairy products (also consumed at breakfast). Recommended egg-cooking methods were boiled or poached, but they could also be fried if a polyunsaturated cooking oil, such as olive oil, was used. The prescribed diets were energy and macronutrient matched, as reported previously

At the end of 12 months both groups had lost about 3 kg in weight.
The investigators measured everything they could to look at diabetic and cardiometabolic biomarkers which might suggest adverse effects of egg eating on the cardiovascular system but they could find no difference between the egg eaters and the non egg eaters.
High egg consumption had no adverse effects on the following factors that are felt to be important in the development of atherosclerosis:

-measures of systemic and vascular inflammation [high sensitivity C-reactive protein (hs-CRP), IL-6, soluble E-selectin (sE-selectin)],

-oxidative stress (F2-isoprostanes), the adipokine adiponectin (which also modulates insulin resistance), and

-glycemia [fasting plasma glucose, glycated hemoglobin (HbA1c), and a medium-term measure of glycemia, 1,5-anhydroglucitol (1,5AG)].

The authors suggested that nutritional guidelines stop worrying about limiting eggs.

Article Two: Half A Million Chinese Can’t Be Wrong

This observational study published in Heart found that egg consumption in a huge Chinese population was associated with less stroke, and major cardiac events (MCE):

Compared with non-consumers, daily egg consumption was associated with lower risk of CVD (HR 0.89, 95% CI 0.87 to 0.92). Corresponding multivariate-adjusted HRs (95% CI) for IHD, MCE, haemorrhagic stroke and ischaemic stroke were 0.88 (0.84 to 0.93), 0.86 (0.76 to 0.97), 0.74 (0.67 to 0.82) and 0.90 (0.85 to 0.95), respectively. There were significant dose-response relationships of egg consumption with morbidity of all CVD endpoints (P for linear trend <0.05). Daily consumers also had an 18% lower risk of CVD death and a 28% lower risk of haemorrhagic stroke death compared to non-consumers.

The lower risk for stroke and cardiovascular death in egg eaters persisted after accounting for known CVD risk factors.

(And yes, I agree this is an observational study which we should take with huge grains of salt and pepper).

Are EGG Whites The Skim Milk Scam of The Egg Industry?

I’ve written about the scam that is skim milk but it occurs to me that egg white consumption is equally nonsensical.

What happens to the wonderfully nutritious yolk of the egg when it is brutally separated from its white? It is put in a container and sold as  liquid egg yolk. Makers of mayonnaise are big consumers of liquid egg yolk.

Thus, like dairy farmers who double their sales by selling skim milk and its dairy fat separately, egg producers are probably delighted that Americans are consuming egg whites , allowing them to get two products from a single egg.

As I wrote previously: not everyone is an egg lover and I’m fine with that. There is no evidence that you have to eat them. You could feel towards them as did Alfred Hitchcock :

“I’m frightened of eggs, worse than frightened, they revolt me. That white round thing without any holes … have you ever seen anything more revolting than an egg yolk breaking and spilling its yellow liquid? Blood is jolly, red. But egg yolk is yellow, revolting. I’ve never tasted it.”

For those that don’t find yellow revolting, however, avoiding egg yolk makes no nutritional sense.

Eggsplicatively Yours,

-ACP

Why Is The American College of Cardiology Distorting The 2015 Dietary Guidelines for Americans?

The 2015-2020 Dietary Guidelines for Americans (DGA) have finally been released and I’m sure that most of you could care less what they say. You may think that they can’t be trusted because you believe the original science-based recommendations have been altered by political, food and agribusiness forces.  Perhaps you don’t trust science to guide us in food choices. Perhaps, like the skeptical cardiologist, you realize that the DGA has created, in the past, more problems than they have corrected.

This time, the skeptical cardiologist believes they have made a few strides forward, but suffer from an ongoing need to continue to vilify all saturated fats.

As such, the DGA no longer lists a recommended limit on daily cholesterol consumption (step forward) but persists in a recommendation to switch from full fat to non fat or low fat dairy products, which is totally unsubstantiated by science, (see my multiple posts on this topic here).

By now you should have gotten the message that a healthy diet consists of lots of fruits, vegetables, nuts, legumes, fish, olive oil and whole grains. The DGA emphasizes this.

There is general consensus that processed foods and added sugar should be limited.

Most of the controversy is about what to limit and how much to limit foods that are considered unhealthy.

Red meat and processed meat remain in the crosshairs of the DGA (although not stated explicitly), but eggs and cholesterol have gotten a pass, something which represents a significant change for the DGA and which I have strongly advocated (here and here).

But hold on, my professional organization, the American College of Cardiology says otherwise.

Misleading Information From the American College of Cardiology

The American College of Cardiology sent me an email and posted on their website the following horribly misleading title:

“2015 Dietary Guidelines Recommend Limited Cholesterol Intake”

The first paragraph of the ACC post reads as follows:

“Physiological and structural functions of the body do not require additional intake of dietary cholesterol according to the 2015 Dietary Guidelines released on Jan. 7 by the U.S. Departments of Health and Human Services (HHS) and of Agriculture (USDA). As such, people should practice healthy eating patterns consuming as little dietary cholesterol as possible. – ”

While technically these statements can be found in the document (by digging way down) the executive summary (infographic below) says nothing about limiting cholesterol.

healthy eating pattern includes

The “Key Recommendations” list eggs as included under a “healthy eating pattern” along with other protein foods.

 

Screen Shot 2016-01-09 at 1.31.18 PM

In addition, there is no mention of cholesterol under what a healthy pattern limits.

 

 

In the same section on cholesterol that the ACC inexplicably has chosen to emphasize, is this sentence:

“More research is needed regarding the dose-response relationship between dietary cholesterol and blood cholesterol levels. Adequate evidence is not available for a quantitative limit for dietary cholesterol specific to the Dietary Guidelines.”

So the DGA recommends no specific limit on dietary cholesterol.

This is consistent with what the DG advisory committee recommended when they wrote “dietary cholesterol is no longer a nutrient of concern.”

The DGA goes on to state:

“A few foods, notably egg yolks and some shellfish, are higher in dietary cholesterol but not saturated fats. Eggs and shellfish can be consumed along with a variety of other choices within and across the subgroup recommendations of the protein foods group.”

The Vegan Agenda

I have a theory on why the ACC went so wildly astray in reporting this information: they are led by a vegan.

The current president of the ACC, Kim Williams, is an evangelical vegan, unrepentant, as this NY times article points out. Apparently, he tries to convert all his patients to the “plant-based diet.”

He is quoted extensively in the ACC blurb on the DGA and is clearly attempting to put a bizarre vegan spin on the new guidelines, ignoring the evidence and the progressive shift from the 2010 guidelines.

Can any information from the ACC be trusted if such basic and important science reporting was so heavily distorted by its President?

No wonder Americans tune out dietary advice: it can so easily be manipulated by those with an agenda.

-May the forks and knives be with you

-ACP

 

 

 

 

Since Dietary Cholesterol Isn’t Important Can I Stop Taking My Cholesterol Drug

A year ago one of my patients began experiencing  chest pain when he walked up hills. Subsequent evaluation revealed that atherosclerotic plaque (95% narrowing of a major coronary artery ) was severely reducing the blood flow to his heart muscle and was the cause of his chest pain. When this blockage was opened up with a stent he no longer had the pain.

Along with other medications (aspirin and plavix to keep his stent open) I had him start atorvastatin, the generic version of Lipitor, a powerful statin drug that has been shown to prevent progression of atherosclerotic plaque and thereby reduce subsequent heart attacks, strokes and death in patients like him

I saw him in the office the other day in follow up and he was feeling great . He asked me “Doc I read  your post yesterday.s Since you say that cholesterol in the diet doesn’t matter anymore, does that mean I don’t have to take my cholesterol drug anymore.?”

His question gets at the heart of the  “diet-heart hypothesis”. The concept that dietary modification, with reduction of cholesterol and fat consumption can reduce coronary heart disease.

The science supporting this hypothesis has never been strong but the concept was foisted on the American public and was widely believed. It was accepted I would  say because it has a beautiful simplicity which can be summarized as follows:

“If you eat cholesterol and fat it  will enter  your blood stream and raise cholesterol levels. This excess cholesterol will then  deposit in your arteries, creating fatty plaque , clogging them and leading to a heart attack.”

This concept was really easy to grasp and simplified the public health recommendations.

However, cholesterol blood levels are determined more by cholesterol synthesized in the liver and predicting  how dietary modifications will effect these levels is not easy.

Since the public has had the diet-heart hypothesis fed to them for decades and given its beautiful simplicity it is hard to reverse this dogma. My patient’s question reflects a natural concern that if science/doctors got this crucial question so wrong, is everything we know about cholesterol treatment and heart disease wrong?

In other words, are doctors promoting a great cholesterol hoax?

Evidence Strongly Supports Statins in Secondary Prevention 

For my patient the science supporting taking a  cholesterol-lowering statin drug is very solid. There are multiple excellent studies showing that in patients with established coronary artery disease taking a statin drug substantially reduces their risk of heart attack and dying.

These studies are the kind that provide the most robust proof: randomized, prospective and blinded.

level of evidenceWhen cardiologists rate the strength of evidence for a certain treatment (as done for lifestyle intervention here) we use  a system that categorizes the evidence as Level A, B, or C quality.

LeveleA quality (or strong) evidence consists of multiple,large, well-done, randomized trials such as exist for statins in patients with coronary heart disease.

Level B Evidence comes from a single randomized trial or nonrandomized studies.

Level C evidence is the weakest and comes from “consensus opinion of experts, case studies or standard of care.”

When treatment recommendations are based on Level C evidence they are often reversed as more solid data is obtained. Level A recommendations almost always hold up over time.

The level of evidence supporting restricting dietary cholesterol and fat to reduce heart attacks and strokes has always been at or below Level C and now it is clear that it is insufficient and should be taken out of guideline recommendations.

Evidence Strongly Supports Atherogenic Cholesterol is Related to Coronary Heart Disease

There are other lines of evidence that strongly support  the concept that  LDL cholesterol (bad cholesterol) or an atherogenic form of LDL cholesterol is strongly related to the development of atherosclerosis. If you are born with really high levels you are at very high risk for coronary heart disease, conversely if you are born with mutations that cause extremely low levels you are highly unlikely to get coronary heart disease.

Thus, the cholesterol hypothesis as it relates to heart disease is very much till intact although the diet-heart hypothesis is not.

Conflating the Diet-Heart Hypothesis and the Cholesterol Hypothesis

There is an abundance of misinformation on the internet that tries to conflate these two concepts. Sites with titles like “The Great Cholesterol Lie” , “The”  Cholesterol Hoax”, The Cholesterol Scam”  abound .

These sites proclaim that cholesterol is a vital component of cell membranes (it is) and that any attempt by diet or drugs to lower levels will result in severe side effects with no benefit

Doctors, according to these types of sites, in collusion with Big Pharma, have inflated the benefits of statin drugs and overlooked the side effects in the name of profit. Often, a “natural” alternative to statins is promoted.  In all cases a book is promoted.

The Great Cholesterol Truths

It’s unfortunate that nutritional guidelines have promoted restriction of cholesterol and fat for so long. These guidelines (like most of nutritional science)  were based on flawed observational studies. They should not have been made public policy without more consensus from the scientific community.  The good news is that ultimately the truth prevails when enough good scientific studies are done.

It is right to question the flimsy foundation of nutritional recommendations on diet and heart disease but the evidence for statin benefits in patients with established coronary heart disease is rock solid.

Hopefully, the less long-winded explanation I provided my patient in the office will persuade him to keep on taking his atorvastatin pills while simultaneously allowing him to eat eggs, shrimp and full fat dairy without guilt.

Why I Recommend the Mediterranean Diet

I recommend the Mediterranean diet (MED) to my patients. Every unbiased, systematic review of the research on diet and heart disease in the last 8 years has concluded that it is the most likely dietary model to provide protection against coronary heart disease. One review concludes

Among the dietary exposures with strong evidence of causation from cohort studies, only a Mediterranean dietary pattern is related to CHD (coronary heart disease) in randomized trials.

The MED is the only comprehensive dietary approach that has been proven to reduce total death  and heart attacks in comparison to standard diets. There are two major randomized controlled trials (the only kind of study that proves the value of a dietary intervention) with this diet.

lyon
From Eric Roehm at http://www.nutritionheart.com

  The first, called the Lyon heart Study,  was in patients who had had heart attacks (secondary prevention) . As this graph demonstrates, those patients randomized to receive instruction on following the Mediterranean diet had a 60% lower death rate and a 70% lower heart attack rate. The second was published last year in the New England Journal of Medicine and was a primary prevention study: that is, participants had not had heart attacks. Participants were randomized to one of three diets: a MED supplemented with extra-virgin olive oil,  MED supplemented with mixed nuts or a control diet (advice to reduce dietary fat). Participants received quarterly individual and group educational sessions and either free provision of olive oil, mixed nuts or small nonfood gifts. The high extra virgin olive oil group ingested an average of 3.6 tablespoons/day (51 grams/day equal to 459 calories/day) of olive oil with 98% of it being extra virgin olive oil. The high nut group ate 8.2% of their total daily calories in the form of nuts, including an additional approximately one ounce packet of nuts (15g of walnuts, 7.5 g of almonds, and 7.5g of hazelnuts) provided by the study coordinators. 7447 persons were enrolled (ages 55 to 80 years) for an average 4.8 years. Those persons following the MED diet (either supplemented with olive oil or nuts) were 30% less likely to have  a major cardiovascular event (heart attack, stroke or death from cardiovascular causes.) There was a statistically significant reduction in stroke rate (≈39%) when considered as an isolated endpoint. We don’t know exactly what components of the MED are the most beneficial.  This trial suggests that olive oil and nuts are at least two of the key ingredient so it makes sense to increase your consumption of these foods. Other studies strongly support fish consumption and alcohol consumption as key components. As I’ve discussed (?ad nauseam) in other posts, full fat dairy and eggs, although banned by most “heart healthy diets”, have not been shown to increase heart disease risk.  Fermented dairy consumption, in particular, in the form of plain full-fat yogurt (not adulterated with sugar) and full-fat cheese is consistently associated with a lower risk of coronary heart disease. Plain full-fat yogurt and full-fat cheese (from goat milk) were consumed by the inhabitants of Crete, the Greek Island on which the original MED was based.

It has to be emphasized that within this pattern of eating you want to be consuming real foods, not processed products of the industrial food industry which have been manipulated to appear healthy due to being “low-fat” or “low cholesterol.”

This is a pattern of eating which is varied, interesting and sustainable.

It’s one that can last a lifetime. ,

Egg Nog: Recipe for a Heart Attack or Heart Healthy?

It’s Christmas Eve and you are starting to make merry. Time to break out the egg nog? Or should you eschew this fascinating combination of eggs, dairy and alcohol due to concerns about heart disease?

    eggCardiac deaths increase in frequency in the days around Christmas.

    Could this be related to excessive consumption of egg nog?

    Egg nog is composed of eggs, cream, milk and booze. All of these ingredients have become associated with increased risk of heart disease in the mind of the public.
    Nutritional guidelines advise us to limit egg consumption, especially the yolk, and use low-fat dairy to reduce our risk of heart disease

    A close look at the science, however, suggests that egg nog may actually lower your risk of heart disease.

    Eggs are high in cholesterol but as I’ve discussed in a previous post, cholesterol in the diet is not a major determinant of cholesterol in the blood and eggs have not been shown to increase heart disease risk.

    Full fat dairy contains saturated fat, the fat that nutritional guidelines tell us increases bad cholesterol in the blood and increases risk of heart attacks. But some saturated fats improve your cholesterol profile and organic (grass-fed, see my previous post) milk contains significant amounts of omega-3 fatty acids which are felt to be protective from heart disease.
    Milk and dairy products are associated with a lower risk of vascular disease!

    Whether you mix rum, brandy, or whisky into your egg nog or you drink a glass of wine on the side you are probably lowering your chances of a heart attack compared to your abstemious relatives. Moderate alcohol consumption of any kind is associated with a lower risk of dying from cardiovascular disease compared to no alcohol consumption.

    So, drink your egg nog without guilt this Holiday Season!
    You’re actually engaging in heart healthy behavior.

Breakfast is Not The Most important Meal of the Day: Feel Free to Skip it

It always irritates me when a friend tells me that I should eat breakfast because it is “the most important meal of the day”. Many in the nutritional mainstream have propagated this concept along with the idea that skipping breakfast contributes to obesity. The mechanism proposed seems to be that when you skip breakfast you end up over eating later in the day because you are hungrier.

The skeptical cardiologist is puzzled. Why would i eat breakfast if I am not hungry in order to lose weight? What constitutes breakfast? Is it the first meal you eat after sleeping? If so, wouldn’t any meal eaten after sleeping qualify even it is eaten in the afternoon? Is eating a donut first thing in the morning really healthier than eating nothing? Why would your first meal be more important than the last? isn’t it the content of what we eat that is important more than the timing?

The 2010 dietary guidelines state

eat a nutrient-dense breakfast. Not eating breakfast has been associated with excess body weight, especially among children and adolescents. Consuming breakfast also has been associated with weight loss and weight loss maintenance, as well as improved nutrient intake

The US Surgeon General website advises that we encourage kids to eat only when they are hungry but also states

Eating a healthy breakfast is a good way to start the day and may be important in achieving and maintaining a healthy weight

A recent study anayzes the data in support of the “proposed effect of breakfast on obesity” (PEBO) and found them lacking.
This is a fascinating paper that analyzes how scientific studies which are inconclusive can be subsequently distorted or spun by biased researchers to support their positions. It has relevance to how we should view all observational studies.

Observational studies abound in the world of nutritional research. The early studies by Ancel Keys establishing a relationship between fat consumption and heart disease are a classic example. These studies cannot establish causality. For example, we know that countries that consume large amounts of chocolate per capita have large numbers of Nobel Prize winners per capitaChocolate Consumption and Nobel Laureates
Common sense tells us that it is not the chocolate consumption causing the Nobel prizes or vice versa but likely some other factor or factors that is not measured.

Most of the studies on PEBO are observational studies and the few, small prospective randomized studies don’t clearly support the hypothesis.

Could the emphasis on eating breakfast come from the “breakfast food industry”?
I’m sure General Mills and Kellogg’s would sell a lot less of their highly-processed, sugar-laden breakfast cereals if people didn’t think that breakfast was the most important meal of the day.

My advice to overweight or obese patients:
Eat when you’re hungry. Skip breakfast if you want.
If you want to eat breakfast, feel free to eat eggs or full-fat dairy (including butter)
These foods are nutrient-dense and do not increase your risk of heart disease, even if you have high cholesterol.
You will be less hungry and can eat less throughout the day than if you were eating sugar-laden, highly processed food-like substances.

.

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Eggs and Heart Disease

The Wonderful Egg and Your Heart

photoI think eggs are wonderful. They are little balls of nutrition that can be prepared in numerous fascinating ways to make breakfast interesting and delicious. I particularly like omelets.  Alas, when I was training as a medical student the medical establishment had embraced the diet-heart hypothesis. It was felt that dietary cholesterol and fat (subsequently modified to saturated fat) by increasing levels of cholesterol in the blood (subsequently modified to raising levels of bad or LDL cholesterol) were responsible for the increasing rate of coronary heart disease that was being observed.

This certainly made sense at the time: If you eat too much cholesterol, of course it’s going to raise your blood cholesterol levels and contribute to the buildup of those nasty cholesterol plaques that would clog your arteries and give you heart attacks and strokes.

Since egg yolks contain 210 mg of cholesterol on average (more recent data suggest they only contain 184 mg/egg), eggs became a target of the dietary police.

The American Heart Association (AHA, the same organization that until recently endorsed sugar-laden cereals like Cocoa Puffs as  “heart healthy”) had decided decades ago to recommend restricting egg consumption. In 2010, AHA guidelines restricted everybody’s total cholesterol to <300 mg per day on the flimsiest of evidence.  From the AHA guidelines:

“Although there is no precise basis for selecting a target level for dietary cholesterol intake for all individuals, the AHA recommends <300 mg/d on average. By limiting cholesterol intake from foods with a high content of animal fats, individuals can also meet the dietary guidelines for saturated fat intake. This target can be readily achieved, even with periodic consumption of eggs and shellfish. As is the case with saturated fat intake, reduction in cholesterol intake to much lower levels (<200 mg/d, requiring restriction of all dietary sources of cholesterol) is advised for individuals with elevated LDL cholesterol levels, diabetes, and/or cardiovascular disease.”

The official US dietary guidelines on the topic of dietary cholesterol read as follows

“the body uses cholesterol for physiological and structural functions, but it makes more than enough for these purposes. Therefore, people do not need to eat sources of dietary cholesterol. Cholesterol is found only in animal foods. The major sources of cholesterol in the American diet include eggs and egg mixed dishes (25% of total cholesterol intake), chicken and chicken mixed dishes (12%), beef and beef mixed dishes (6%), and all types of beef burgers (5%). Cholesterol intake can be reduced by limiting the consumption of the specific foods that are high in cholesterol. Many of these major sources include foods that can be purchased or prepared in ways that limit the intake of cholesterol (e.g., using egg substitutes). Cholesterol intake by men averages about 350 mg per day, which exceeds the recommended level of less than 300 mg per day. Average cholesterol intake by women is 240 mg per day.

Dietary cholesterol has been shown to raise blood LDL cholesterol levels in some individuals. However, this effect is reduced when saturated fatty acid intake is low, and the potential negative effects of dietary cho- lesterol are relatively small compared to those of saturated and trans fatty acids. Moderate evidence shows a relationship between higher intake of cholesterol and higher risk of cardiovascular disease. Independent of other dietary factors, evidence suggests that one egg (i.e., egg yolk) per day does not result in increased blood cholesterol levels, nor does it increase the risk of cardiovascular disease in healthy people. Consuming less than 300 mg per day of cholesterol can help maintain normal blood cholesterol levels. Consuming less than 200 mg per day can further help individuals at high risk of cardiovascular disease.”

Americans were being told to severely restrict their egg consumption, especially if they had high cholesterol levels, diabetes, or heart disease. Even one egg a day seemed too much. As a cardiologist in training I dutifully took these recommendations to heart. I can’t tell you how many egg beater or egg white omelets I cooked over the next 25 years.

As more evidence accumulated, however, the bulk of the scientific evidence was coming down clearly on the side of eggs and the lack of effect of dietary cholesterol on blood cholesterol levels. As The Skeptical Cardiologist I began embracing the heresy of eating eggs, yolk and all, about two years ago.

Several large epidemiological studies have examined the association of egg consumption and serum cholesterol. The Framingham Heart Study examined the serum cholesterol in high versus low egg consumption and found no significant difference in either men or women. The association between self-reported dietary intake of eggs and serum cholesterol was examined in a population of 12,000 men in the Multiple Risk Factor Intervention Trial. Paradoxically, the men who consumed more eggs had lower serum cholesterol than those who consumed fewer eggs.In the Third National Health and Nutrition Examination Survey (NHANES III), the diets of 20,000 participants were evaluated.

“Compared to egg consumers, nonconsumers  had higher rates of inadequate intake (defined by Estimated Average Requirements (EAR) or < 70% Recommended Dietary Allowance (RDA)) for vitamin B12 (10% vs. 21%), vitamin A (16% vs. 21%), vitamin E (14% vs. 22%) and vitamin C (15% vs. 20%). After adjusting for demographic (age, gender and ethnicity) and lifestyle variables (smoking and physical activity), dietary cholesterol was not related to serum cholesterol concentration. People who reported eating > or = 4 eggs/wk had a significantly lower mean serum cholesterol concentration than those who reported eating < or = 1 egg/wk (193 mg/dL vs. 197 mg/dL, p < 0.01”

Study after study in the next 20 years showed that egg consumption was not associated with coronary heart disease and strokes. A more recent study from Spain shows no association of egg consumption on cardiovascular disease. A meta-analysis of all prospective cohort studies published in 2013 concluded that there was no association between higher egg consumption and coronary heart disease or stroke. Studies (randomized controlled trials) that  actually prove that egg consumption causes cardiovascular disease are totally lacking. Nutritional guidelines should have concluded  that there was no reason to restrict egg consumption in the vast majority of Americans.

Unfortunately, the AHA guidelines (and mainstream nutritional advisors) to this day continue to embrace the 300 mg/ day limit on cholesterol (although most other countries have dropped it). Most of my patients, having heard that eggs are bad for the heart, mistakenly try to restrict the amount they eat or eat egg whites. I see my fellow doctors in the doctors’ lounge taking boiled eggs out of the refrigerator, scooping the yolk out and eating only the egg white.

Why doesn’t more cholesterol in the diet lead to higher blood cholesterol level and subsequently to heart attacks? The answer is complicated, beyond the scope of this blog, but it illustrates how amazingly complex the body’s regulation of lipids and lipoproteins is, as well as how complicated the process of atherosclerosis is.

There are at a very basic level 3 main types of fat that doctors measure in the blood to help us gauge heart disease risk: the low density lipoprotein (LDL)  cholesterol portion or “bad”, the high-density lipoprotein (HDL) cholesterol or “good,” and the triglycerides (esterified fatty acids). On a very simplistic level, we tell patients that higher LDL levels tend to build up fatty plaques, whereas higher HDL levels can be thought of as reducing fatty plaques. When we eat an egg there is a complex reaction to the fats, proteins, sugar, and cholesterol absorbed into the blood stream.cholesterol graphic Although the LDL rises (which might increase coronary artery disease (CAD) risk), the HDL also rises (which might lower CAD risk) and there is a variable response of triglycerides. To further complicate things, each of the cholesterol fractions has  good forms and bad forms. LDL can be in a large, “fluffy” state that is not prone to promoting plaque formation or a small, dense form that does promote plaque formation. Eggs seem to promote the less atherogenic forms of both LDL and HDL. In addition, inflammation plays an important role in the process of atherosclerosis. Certain components of egg yolks may actually reduce inflammation, making plaque formation less likely.

Certain components of eggs may be beneficial and outweigh any theoretical concern about cholesterol consumption.. Eggs are the major sources of lutein and zeaxanthin, two potent anti-oxidants, which in addition to their recognized protective effects against macular degeneration and cataract formation, may also reduce LDL oxidation.

Eggs also contain choline, a nutrient that is needed for membrane formation, methylation and acetylcholine biosynthesis, which plays a major role in normal fetal development. Some studies suggest a role of choline in protecting against Alzheimer’s disease

Eating eggs may contribute to weight loss compared to eating carbohydrates. A recent study compared two different breakfasts, a bagel-based and an egg-based breakfast. During the egg period, men had a significantly lower caloric intake not only in the next meal, but also in the following 24 hours.

To make things more complicated, all eggs are not created equal. Hens that are allowed to range freely on a farm and eat grass, bugs and what might be considered their normal diet, have a different amount of omega-3 fatty acids than those that are fed grain. Given America’s current obsession with fish oil supplements (see my prior post), this makes these eggs perceived as healthier. By manipulating the diet of hens, even those stuck in cages, the omega-3 content of eggs can be increased. Is this healthier?

The limit on dietary cholesterol of 300 mg imposed by the AHA and the USDA in their guidelines, unnecessarily has my patients worrying about cholesterol in all the things that they eat. For example, there is a lot of cholesterol in shellfish. There is no evidence that eating shellfish is bad for the heart or your cholesterol profile. For example, this recent study showed no effect of eating cold water prawns on plasma cholesterol or lipoproteins.

The Bottom Line:

Eggs are an affordable (15 cents/egg) source of high quality protein and fat. Although they contain a lot of cholesterol, there is no evidence (with the possible exception of diabetics) that egg consumption is related to risk of coronary heart disease; they may in fact reduce the risk of stroke.

Since this new evidence has emerged, I regularly enjoy the deliciousness of a three egg omelet with cheese and other ingredients without guilt and I encourage my patients to do the same.photo Personally, especially in my home kitchen, I try to eat eggs that come from hens that are raised under more natural and humane circumstances as I view them as healthier than eggs from factory farms.

Not everyone is an egg lover and I’m fine with that. There is no evidence that you have to eat them. You could feel towards them as did Alfred Hitchcock :

“I’m frightened of eggs, worse than frightened, they revolt me. That white round thing without any holes … have you ever seen anything more revolting than an egg yolk breaking and spilling its yellow liquid? Blood is jolly, red. But egg yolk is yellow, revolting. I’ve never tasted it.”hitch