Category Archives: Dietary Cholesterol and Eggs

Sheepshead Fish: Vulnerable and Gender Fluid Yet Mighty Tasty

The skeptical cardiologist and his Eternal Fiancee’ have escaped dreary and oceanopenic St. Louis and are spending a week in allegedly sunny and definitely beachy San Diego.

Upon arrival we took in a Farmer’s Market in Little Italy and stumbled into Ironside Fish and Oyster.screen-shot-2017-01-22-at-9-07-04-am
Always in search of heart-healthy, unique and local fish dishes, I spotted on the menu a luncheon special of sheepshead fish.

Kelly Fukushima is the local fisherman who caught my fish
Kelly Fukushima is the local fisherman who caught my fish.

California sheepshead (Semicossyphus pulcher), the existence of which I was previously unaware, turned out to be a fascinating and most delicious fish.


Before I could order it, I had to verify that I wasn’t contributing to the extinction of a species.  The IUCN Red List of Threatened species lists the CS as “vulnerable” because:


After learning the CS was vulnerable, I had to make a critical decision: should I eat it before it disappeared, robbing me of a chance to ever taste it, or should I order something that wasn’t vulnerable, thus contributing to the preservation of the continuing biodiversity of the planet. I elected to taste it.

Gender Fluid Fish

Further research revealed that the CS transitions from a reproductively functional female at birth, to a functional male during the course of a lifespan in response to social factors (?reverse Bruce Jenner).

According to this is termed sequential hermaphroditism:

In some sequentially hermaphroditic fish species, animals develop first as male and then switch to female (a condition called protandry), and in others, the individuals develop first as female and then switch to male (protogyny).

Clownfish (as in Finding Nemo) do the opposite of the sheepshead and are protandrous:

This species lives within sea anemones in groups of two large fish and many small fish. The two large fish are the only sexually mature fish and are a male and female breeding pair. All of the smaller fish are male. If the large breeding female is removed, her male mate changes sex to female and the next largest fish in the group rapidly increases in size and takes over the role as the sexually mature male.

While waiting for the vulnerable and sequentially hermaphroditic sheepshead to arrive, I sampled an equally

img_8160stupendous and heart-healthy side of cannelloni bean cassoulet. Chock full of Mediterranean diet essentials including kale, beans and mustard seeds, it worked really well as an appetizer.


Do not make the mistake of looking at this youtube video while waiting for your sheepshead entree’ as I did. The disturbing human-like teeth will not be part of your meal.

Finally, the 4 ounces of CS arrived, perfectly prepared a la plancha,

img_8162with an accompanying lemon butter sauce that was divine. Although butter is not officially a big part of the Mediterranean diet, frequent readers of the skepcard know that dairy fat does not make you fat or promote heart disease, and is fine (in moderation of course) as part of a heart-healthy diet.

Speaking of lingering bad dietary advice, if you investigate the nutritional content of sheepshead at a site like SELF Nutrition, the screen-shot-2017-01-22-at-10-18-54-amold canard that we should be limiting our dietary cholesterol raises its ugly head. Because sheepshead contain significant amounts of cholesterol (presumably from carnivorously munching on shellfish with its scary human-like choppers), the misguided nutritionists at SELF Nutrition and other would-be nutritionistas pronounce it as not optimally healthy.

Semiccossyphusilly Yours


PS. If you’d really like to get your nerd on about sequential hermaphroditism check out this graphic showing the independent evolution of this feature across different phylogenetic lineages!















Misleading Information From the American College of Cardiology


“2015 Dietary Guidelines Recommend Limited Cholesterol Intake”

The first paragraph of the ACC post reads as follows:



healthy eating pattern includes



Screen Shot 2016-01-09 at 1.31.18 PM






So the DGA recommends no specific limit on dietary cholesterol.


The DGA goes on to state:


The Vegan Agenda






-May the forks and knives be with you






Are Pasture-Raised Hen Eggs More Heart Healthy Than Conventional Eggs

Eggs (and dietary cholesterol) should no longer be restricted in a heart-healthy diet as the skeptical cardiologist has pointed out here.

But if we’re eating eggs should they come from “pasture-raised” (or grass-fed or pastured) hens?

The arguments for choosing hens that can roam freely and eat bugs, clover, and grass from the ground beneath them are of four types:

1. Ethical. The vast majority of eggs come from hens that are kept in a small cage most of their life and are never allowed to see the light of day or engage in their normal activities. This is inhumane.

2. Esthetic. Eggs from pasture-raised hens (PRH) taste better.

3. Health. PRH eggs are more nutritious because of the better food ingested by PRH and the manner in which they live and are treated.

4. Environmental. PRH operations are more sustainable and contribute less toxins and antibiotics to the environment.

Ethical Arguments

PETA gives a horrific description of what factory farm hens endure here. Here’s an excerpt:

“hens are shoved into tiny wire “battery” cages, which measure roughly 18 by 20 inches and hold up to 10 hens, each of whom has a wingspan of 32 inches. Even in the best-case scenario, each hen will spend the rest of her life crowded in a space about the size of a file drawer with four other hens, unable to lift even a single wing.


PETA and vegans advocate not eating any animals or animal products. They have an inherent bias against omnivorous diets and their interpretation of the nutritional science always reflects that.

I sympathize with the plight of factory farms hens, but it is very difficult to martial scientific arguments in the area of the ethical treatment of animals.

 Nutritional Differences

A brief Google search yields dozens of websites which proclaim that PRH eggs are far more nutritious and better for you than conventional eggs. When a source for this claim is listed it comes from one of two studies:

1. Mother Earth News (Oct/Nov 2007). Mother Earth News is not known for its scientific rigor, but they did publish an analysis of the nutritional content of eggs from 14 farms with PRH and compared it to what the USDA had published for the nutritional content of conventional eggs.

Let me just say that this “study” would never be published in a reputable scientific journal due to flaws in the study design. For one thing, the PRH eggs should have been compared to conventional eggs analyzed at the same time in the same way in a blinded fashion. Also, there is no statistical analysis of the data.

Here is how Mother Earth News summarizes their findings:


PRH eggs compared to the conventional eggs had

• 1/3 less cholesterol
• 1/4 less saturated fat
• 2/3 more vitamin A
• 2 times more omega-3 fatty acids
• 3 times more vitamin E
• 7 times more beta carotene

You can see the data in this PDF (PRH eggs versus conventional nutrients.)

Eggs were vilified during the heyday of the anti-fat movement because of their cholesterol and saturated fat content. We now know that neither one of these macronutrients causes heart disease; so the fact that PRH eggs have less of them is irrelevant. In addition, no other study has replicated the findings with respect to cholesterol and saturated fat content.

The higher levels of Vitamin A, Vitamin E and beta-carotene make sense given the differing food intake of PRH compared to factory hens, but again, there is nothing to suggest Americans aren’t consuming plenty of these vitamins in other foods. In addition, studies looking at supplementing diet with Vitamin E and beta-carotene have shown no overall health or cardiovascular benefits.

2.2010 paper by Karsten, et al. in Renewable Agriculture ad Food Systems.

This study is a legitimate peer-reviewed scientific study published in a reputable scientific journal by researchers who did not have any obvious bias or conflict of interest.. Bias can run both ways in these types of studies, as any research supported by the conventional egg industry would receive pressure to find no difference between conventional and PRH eggs. However, studies funded by advocates of PRH eggs would be hoping to find significant benefits of their eggs.

The 2010 study  found:

“Compared to eggs of the caged hens, pastured hens’ eggs had twice as much vitamin E and long-chain omega-3 fats, 2.5-fold more total omega-3 fatty acids, and less than half the ratio of omega-6:omega-3 fatty acids (P<0.0001).”

Of the nutrient differences reported between PRH and conventional eggs the omega-3 differences are the most intriguing. Both of these studies found a doubling of omega-3 fatty acids in PRH eggs, which are generally considered the healthiest of all fatty acids. The second study found a lower ratio  of omega-6:omega-3 in the PRH eggs. The relative benefits of omega-6 and omega-3 fatty acids in the diet is a topic of considerable controversy in the scientific literature right now but, in general, recommended diets like the Mediterranean feature higher omega-3 to omega-6 ratios than standard Western diets.

There are no studies looking at the differing effects of consuming PRH versus conventional eggs on biomarkers or outcomes in humans.

Thus, we have no idea whether the overall package of nutrients delivered in the PRH eggs would improve blood pressure, cholesterol parameters or markers of inflammation or whether they could lower your risk of heart attack or stroke.


I have been eating PRH eggs whenever possible for the last few years and I swear they taste better than conventional eggs. In preparation for this post, I had decided that a blinded tasting of eggs would be needed to support my totally subjective assessment of PRH egg superiority.

However, it turns out that several blinded tasting egg comparison have already been done and the results are quite shocking to me.

The Food Lab at Serious Eats (which, by the way is dedicated to “unraveling the mysteries of home cooking through science”)  had 8 tasters  taste scrambled eggs prepared from PRH eggs, conventional hen eggs and various omega-3 supplemented eggs

One half of the tasters found no difference in taste between the various kinds of eggs, but those who did favor an egg favored the PRH eggs and the higher omega-3 eggs. The yolks of the PRH eggs and omega-3 eggs were more on the “intensely orange” end of the spectrum.

Did the more orange yolks taste better or were the tasters biased by the more intense color?

The tasting was repeated, this time with the color of the eggs masked by adding green food coloring. In this color-blind tasting:

“most people could not taste any difference in the eggs. Those who did taste a difference picked a totally different batch of eggs—this time, there was no clear winner, and no discernible trends based on how the eggs were produced or levels of omega-3’s”

A food writer for the Washington Post did a similar taste test, this time with actual blind folds, and although she was convinced that the eggs from her backyard hens would be superior, a panel of six tasters could find no difference between hers, conventional eggs, and organic eggs.

Although these taste tests haven’t been published in peer-reviewed scientific journals, they are likely as close as we are going to get to the truth. The fact that the organizers of the tests were biased towards PRH eggs tasting better but found no difference means almost certainly, alas, that there is no taste superiority for PRH eggs.

Are PRH Eggs Worth The Extra Cost?

Ultimately, this is a question for each individual. True PRH eggs cost upwards of 5 dollars per dozen compared to around 2$ per dozen (prior to the recent avian flu outbreak).

It is hard to justify that cost based on nutritional, health or taste considerations as I’ve shown.

Chelsea Pearson, communing with her hens

My oldest  daughter, Chelsea Pearson, has, along with thousands of other city dwellers, begun raising chickens in her backyard.  In addition to collecting delicious eggs from the hens, she has become attached to them and finds them to be interesting and enjoyable pets.

After weighing the ethical and environmental concerns despite the absence of conclusive health benefits or taste superiority I have elected to continue paying a premium for PRH eggs.

I have the financial resources to justify this decision but for those without such resources I totally  understand a decision to eat conventional eggs.

Eggstatically Yours,


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










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

Evidence Strongly Supports Statins in Secondary Prevention 









Evidence Strongly Supports Atherogenic Cholesterol is Related to Coronary Heart Disease



Conflating the Diet-Heart Hypothesis and the Cholesterol Hypothesis




The Great Cholesterol Truths




Eggs and Heart Disease

The Wonderful Egg and Your Heart



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 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 :
