The skeptical cardiologist was hard at work researching cardiovascular disease in the Virgin islands last week. It was a tough assignment, but I felt I was the right man for the job. It required me to leave the snow and freezing temperatures of St. Louis to fly to St. John where the daytime highs are 82 and the nighttime lows are 73 and the skies are clear to partly cloudy every day.
The United States Virgin Islands (USVI) are located 1100 miles southeast of Miami and cover 346 square miles, with an estimated population of 112,000 residents, who live primarily on three islands: St. Croix, St. Thomas, and St. John. About 78 percent of the residents are Black (African-Caribbean), 10 percent White, and 12 percent “other.” Just under half (49 percent) of the population was born in the Virgin Islands. Native born or naturalized Virgin Islanders are U.S. citizens.
Interestingly, the CDC has reported that the USVI has the lowest rate of heart attack (2.1%) of any state or territory in the US. (W. VA is highest at 6.4%). In addition, a recent study, has shown that blacks in the USVI have a significantly lower rate of cardiovascular disease than blacks in the other 50 states.
Using my cardiology sleuthing skills on site in several Cruz Bay bars and at various beaches and hiking trails I have come up with several hypotheses for the remarkably low rate of cardiovascular disease in this area.
1. Rum-based beverage consumption. Rum is big business in the USVI. As the result of a public-private partnership deal in 2009 the USVI helped Captain Morgan Rum move their distillery from Puerto Rico to St. Croix and helped expand and improve the Cruzan Rum distillery on the islands. As part of the deal the US Congress gives money from excise taxes back to the USVI
The “cover-over” program returns $10.50 of the total $13.50 distilled spirits tax collected per proof gallon to the territories. In 1999, Congress temporarily increased the “cover-over” rate to $13.25 and has extended that rate ever since when it comes up for a bi-annual vote. As part of the agreements with Diageo and Fortune, the USVI government will return a portion of the cover-over funds to the companies in the form of the marketing support, financing of the new or expanded distilleries and waste water treatment facilities, tax incentives and molasses support so companies can secure the key rum ingredient molasses at a competitive price.”
This must explain why rum-based drinks are incredibly cheap in St John. The skeptical cardiologist and the significant other of the skeptical cardiologist (SOSC) found, during the course of their research, that at many beachfront bars, multiple rum-based drinks such as Dark and Stormy’s, Painkillers, and Rum Punches were priced at 3$ during happy hour. Happy hours extended for particularly long hours.
It is well known that alcohol in general raises the good cholesterol, HDL, and lowers cardiovascular disease when consumed in moderation. But could rum have a special cardioprotective effect? More studies are clearly needed in this area.
2.Incredibly beautiful weather, beaches and topography. Our extensive investigations led us to detailed examinations of Solomon, Honeymoon, Caneel, Trunk, Cinnamon, Gibney, Jumbie, and Salt Pond Bay beaches on St. John At these beaches we found that the clear, warm, aquamarine waters with coral reefs close to shore allowed for excellent snorkeling, thus promoting extensive physical activity. Similarly, multiple hiking trails in the Virgin Islands National park (which covers two-thirds of St. John), stimulated the desire to walk. Physical activity is known to substantially reduce the risk of cardiovascular disease. Could increased physical activity related to a conducive environment be playing a role here?
3.Sun exposure. Some studies suggest a role of low Vitamin D levels in promoting heart attacks. Vitamin D deficiency links to cardiovascular disease can be found in a number of studies demonstrating a 30% to 50% higher cardiovascular morbidity and mortality associated with reduced sun exposure caused by changes in season or latitude. Conversely, the lowest rates of heart disease are found in the sun-drenched Mediterranean coast and in southern versus northern European countries. Cardiac death has been reported to be the highest during winter months.
Is increased sun exposure responsible for the lower heart attack risk on the Virgin Islands?
4.Diet. Our research took us to several restaurants in Cruz Bay, however, I don’t feel that we got a good feel for the typical diet of the people of USVI. The only restaurant that was not owned and operated by rich white people and frequented by predominantly rich white people was an overpriced BBQ joint. The food did not seem different from what one could easily get in a modestly sized mainland city.
5. Relaxed Lifestyle. Epidemiological data show that chronic stress predicts the occurrence of coronary heart disease (CHD). Employees who experience work-related stress and individuals who are socially isolated or lonely have an increased risk of a first CHD event. In addition, short-term emotional stress can act as a trigger of cardiac events among individuals with advanced atherosclerosis. Could the laid back life style in the Caribbean where every one seems to be on “island time” be a factor?
Clearly more research is needed into this topic. Rest assured, the skeptical cardiologist and SOSC will be actively investigating these potentially life changing issues in more detail next winter.
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.
The skeptical cardiologist has to admit that when he drinks milk or puts it in his coffee or cooks with it he almost exclusively drinks “organic”, non-homogenized milk obtained from dairy cows which are grass-fed and spend most of their lives grazing in a pasture.. In previous blogs I’ve laid out the evidence that supports that dairy products in general do not increase the risk of heart and vascular disease and, in fact, may lower that risk.
Full fat dairy has gotten a bad rap because it contains high levels of saturated fat. However, just as total fats were inappropriately labeled as bad , it is now clear that all saturated fats are not bad for the heart.
Although I recommend full fat dairy products to my patients I haven’t emphasized the organic or grass-fed aspect because I didn’t think there was enough good evidence that this is healthier than other kinds of milk and it is more expensive. There is evidence from small studies that cows consuming a more natural diet of grass and legumes from a pasture have higher levels of omega-3 fatty acids in their milk than those confined indoors and eating corn.
I keep my eyes (and ears) open for papers in this area.. One such paper appeared in the online peer-reviewed publication PLOS recently. I was driving to the hospital, listening to NPR when I first heard about it. Melissa Block was interviewing NPR correspondent Allison Aubrey . Her take, in a more subdued written form here is similar to many news outlets.
Allison summarized the findings as follows
The researchers compared organic and conventional milk head-to-head. They analyzed about 400 samples over an 18-month period, to account for seasonal differences. And the samples were taken from, you know, all different parts of the country. And they found that organic milk had about 62 percent more of the heart healthy omega-3s, compared to conventional milk.
When asked for an explanation she said
It really comes down to watch what the cows were eating. Organic milk is produced from cows that spend a lot more time out on pasture, and they’re munching on grasses and legumes. And these greens are rich in omega-3 fatty acids. So as a result, the milk they produce has more omega-3 fatty acids.
Wait a minute! I said , you’re confusing “organic” and “grass-fed” or “pasture raised ” they are two totally different things although they can overlap. I totally get the concept of a healthier diet for the cows increasing omega-3s in their milk but I haven’t seen anything that would suggest reducing pesticide or antibiotic usage does that. The radio did not respond. Also, I asked, is it possible to use the term omega-3 without prefacing it with “heart healthy”?
Once you start demanding to know more about the conditions of the cows that made the milk you drink things can become complicated. A cow can be grass-fed but not pasture raised, meaning that it stayed indoors and was fed hay. A cow can be outside “grazing ” but be given corn to eat. Prior to looking at the PLOS one article, I did not assume organic implied anything about how the cows were fed or grazed.
It turns out that in 2010 the USDA announced guidelines that mandated, among other things, for a dairy to be called “organic”, its dairy cows had to spend at least 120 days grazing on pasture.Thus, there is some correlation between organic and pasture raised/grass-fed but not a complete one.
The PLOS one study looked at geographical variation in the difference between organic and conventional milk fatty acid content. Northern California was the only region in which there was no significant difference. The authors speculated that this was because conventional farmers in Norther California usually have cows that roam on the pasture and eat grass and legumes. Thus, it appears the differences between organic and conventional milk are primarily due to what the cows were eating rather than the presence or absence of pesticides, antibiotics, GMOs, or hormones.
Allison Aubrey went on to say
But you know, I should say that there’s a trade-off here because in order to get all these extra omega-3s, you’ve got to drink whole milk. And you know, if you opt for the low-fat dairy – say, 1 percent fat -you’ve skimmed off most of these omega-3s. So the question is, you know, can you afford the extra calories in fat. If you choose the whole milk, you might need to trim a few calories from elsewhere in your diet.
To which I responded “Yes, by all means drink whole milk, there is no evidence that it adds to obesity. You will naturally want less calories down the line and you will get the benefit of good saturated fats.”
I'll continue to pay extra to drink milk from Trader's Point Creamery that I pick up at Whole Foods. I like their milk because I've visited their farm in Indiana and talked to their (plastic surgeon) owner and I like what he says on the website about their milk (ignoring the part about a “better immune system”.
We let our cows graze on 140 acres of pesticide free pasture, which results in milk with more healthy fats like Omega 3 and CLA (conjugated linoleic acid). Grassfed milk also contains more nutrients like beta carotene and vitamins A and E than milk produced using standard feeds. To all of us this means more nourishment and a better immune system for our bodies.
I’m going to end with the summary from the PLOS one article (DMI=dry matter intake, LA=linolenic acid, an omega-6 fatty acid) which emphasizes the importance of grazing and forage-based feeds not the organic aspects of milk.
We conclude that increasing reliance on pasture and forage-based feeds on dairy farms has considerable potential to improve the FA profile of milk and dairy products. Although both conventional and organic dairies can benefit from grazing and forage-based feeds, it is far more common—and indeed mandatory on certified organic farms in the U.S.—for pasture and forage-based feeds to account for a significant share of a cow’s daily DMI. Moreover, improvements in the nutritional quality of milk and dairy products should improve long-term health status and outcomes, especially for pregnant women, infants, children, and those with elevated CVD risk. The expected benefits are greatest for those who simultaneously avoid foods with relatively high levels of LA, increase intakes of fat-containing dairy products, and switch to predominantly organic dairy products.
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?
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
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.
The Skeptical Cardiologist is a big fan of yogurt. I prefer yogurt in its unadulterated state, 3.5 to 5% milk fat, no sugars added at the factory. Preferably sourced from a local dairy where the cows range freely and eat grass. In this form, yogurt is a very healthy, nutrition-dense, vitamin- enriched food that supplies calcium, essential vitamins, protein and fats.
Yogurt, like all full fat dairy products (with the possible exception of butter) does not increase the risk of heart disease. In fact, some epidemiologic studies show that yogurt consumption is associated with lower risk of heart attacks. It is also associated with less weight gain over time .Because these observational studies can never prove causation we cannot conclude that eating yogurt will reduce our risk of cardiovascular disease or help us lose weight, but certainly there is nothing to suggest that it contributes to heart disease or obesity.
The Frozen Yogurt Scam: Substitute Sugar and Chemicals for Dairy Fat
Yogurt has a reputation as being a “healthy snack.” Sales of yogurt are increasing rapidly with Greek and frozen yogurt, in particular, showing spectacular growth.
Unfortunately, a great hoax has been perpetrated on the American public. Following advice generated from organizations like the American Heart Association and the USDA government nutritional guidelines, with the idea that they are making healthier choices, Americans are choosing yogurt that is nonfat or low-fat.
When the fat is taken out of yogurt, almost invariably sugar in one form or another is added in by the food industry to enhance flavor and make it palatable.
The Healthiest Froyo Orders at Pinkberry, Baskin Robbins, and More Get your frozen yogurt fix without downing an entire mealʼs worth of calories
The teaser line read as follows:
Frozen yogurt may offer a healthier alternative to ice cream, but it can be easy to fall into a calorie trap when you load up on rich flavors and toppings. Check out our cheat sheet to see which froyo combos to order at popular chains. Each one is low in fat and calories—so you can enjoy a guilt-free summer treat!
The number one recommendation was for a sugar and carbohydrate bonanza with the title: “Pinkberry’s Strawberry Classic,” which contains the followingnutritional ingredients:
Nonfat milk, sugar, strawberry flavor (strawberries, sugar, water, natural flavors, fruit and vegetable juice [for color], guar gum, sodium citrate), nonfat yogurt (pasteurized nonfat milk, live and active cultures), nonfat yogurt powder (nonfat milk, culture), fructose, dextrose, natural flavors, citric acid, guar gum, maltodex- trin, mono- and diglycerides, rice starch
Sugar is listed twice and overall there are 23 ingredients that have been added to make this pale imitation of real yogurt palatable. Ironically, Pinkberry claims to have “real” yogurt but the only thing I could tell from their website is the following:
Pinkberry is made with REAL nonfat milk, not from cows treated with rBST hormones, and REAL nonfat yogurt, among many other natural ingredients.
The Shape magazine article recommends you add real strawberries plus a “balsamic glaze” and estimates the total calories as 165 with 144 of which are provided by sugar (36g).
The Skeptical Cardiologist does not recommend this as a “healthy snack” because of the massive amount of sugar, unrefined carbohydrates, and added chemicals. Michael Pollan’s Food Rules are violated multiple times with this ultraprocessed concoction including “Avoid foods with more than 5 ingredients” and” avoid foods which have some form of sugar (or sweetener) listed among the top 3 ingredients”.
Eat Real Food Not Ultraprocessed Industrial Concoctions
In contrast to the typical nonfat frozen yogurt sugar nightmare, a 5 oz serving of whole milk yogurt from Traders Point Creamery has 90 calories total, 5 grams of fat, 7 total grams of carbohydrate and 5 grams of protein.
There are four ingredients listed on the glass bottle for Traders Point Creamery whole milk yogurt: organic whole milk, organic skim milk, live cultures, and probiotic cultures. The cows are also pastured raised and grass-fed.
This is a yogurt I can recommend.
The food industry routinely presents us with ultra-processed, “food-like” substances that are promoted as more healthy but contain added sugar and refined carbohydrates to enhance taste and promote excess consumption. When we consume sugar added by food processing, we are consuming calories without any nutritional value.
There is no science that tells us that substituting sugar for dairy fat is better for you or for your heart. Several lines of evidence suggest excess consumption of sugar and refined carbohydrates contribute to obesity, inflammation and may increase cardiovascular and chronic disease risk. The high glycemic index and resulting spike in blood sugar may trigger hormonal responses that increase inflammation and fat storage.
America’s obesity epidemic seems to have developed as Americans, following dietary guidelines not based in science, began seeking out low-fat substitutes for real foods. Thus, we have witnessed the explosion of fat-free or low-fat frozen yogurt as food marketers and the obliging “health” media trumpeted the health benefits of these products with no evidence to support the claims.
Being the skeptical cardiologist I have to point out that there has been a shameless, unsubstantiated over-hype of the benefits of yogurt in all sorts of areas including immunity, “digestive health,” bladder cancer, and eczema. I’ll review the health benefits (if any) of the “probiotic” or “prebiotic” features of yogurt and the growth of Greek yogurt in future posts.
Full Disclosure: I have no connections with and receive no support from any food industry sponsored organization. I’m not selling anything. I’m just an unbiased cardiologist seeking the truth so I can make evidence-based recommendations on diet to my patients. I do eat Traders Point Creamery yogurt and drink their milk but have no other connection to the whole organic yogurt I featured in the pictures. I have, however, visited their farm and can attest to the fact that the cows are grazing in a pasture and are well treated.
I 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. 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. 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.”
In my previous post, I referenced USDA guidelines which recommend consuming dairy but only in a low-fat form. How did the mainstream nutritional community decide the American public should shift from full fat dairy to low or no fat dairy? Prior to the 1950s there was little concern in nutritional research about fat in the American diet. Beginning in the 1950s, it became apparent that heart disease, coronary artery disease (the cause of heart attacks) in particular, had become the major cause of mortality in western countries.
The American epidemiologist, Ancel Keys, became convinced in the mid 1950s that dietary fat and cholesterol were related to heart disease. In 1970 published his “Seven Countries Study” which found a correlation between per capita fat consumption and the prevalence of heart disease in seven cherry-picked countries. These kinds of studies can be useful for developing theories about which factors might cause disease, however, they cannot prove that a dietary factor causes the disease.
Messerli recently published a tongue-in-cheek analysis of the relationship between per capita chocolate consumption in a particular country and the number of Nobel Laureates produced by that same country that illuminates the weakness of this type of study.
This is the main figure from that study: Chocolate Consumption and Nobel Laureates
There is a very nice relationship demonstrated which suggests that the more chocolate consumed in a particular country, the more Nobel Laureates produced. However, no one would seriously believe that chocolate consumption causes the kind of brilliance needed to do achieve a Nobel prize. Clearly, there are confounding variables or factors. Sometimes, confounding factors are clear and can be accounted for, but often they are not clear and cannot be accounted for.
Early studies of this type demonstrated that there was a relatively strong association between the per capital supply of milk or some component of milk and heart disease mortality. In other studies, changes in gross milk production over time and changes in heart disease deaths were shown to correlate.
“the National institute of Health (NIH) had begun (by 1988) advising every American old enough to walk to restrict fat intake, and the president of the American Heart Association (AHA) had told Time magazine that if everyone went along, “we will have (atherosclerosis) conquered” by the year 2000. The Surgeon General’s Office itself had just published its 700-page landmark “Report on Nutrition and Health,” declaring fat the single most unwholesome component of the American diet.”
Such recommendations have resulted in a whole industry devoted to developing low-fat food-like substances which the public has perceived as healthier than the natural high fat original foods. Arguably, adoption of highly processed low-fat foods, which usually increase palatability by adding refined carbohydrates , sugar, or high-fructose corn syrup have contributed to America’s obesity epidemic. This, in turn through increasing obesity-associated diabetes, hypertension, and abnormal lipid profiles could have the unintended consequence of increasing heart disease.
The major focus of low-fat dietary recommendations has been to lower red meat consumption due to the high levels of saturated fat found in pork and beef. However, despite having a significantly different saturated fat composition, dairy products have been tarred with the same brush, so to speak. This has progressed to the point where, if one enters a frozen yogurt establishment (these businesses have proliferated at an alarming rate in the last few years) it is virtually impossible to find a full fat formulation of yogurt. Prominently featured are the words “no-fat” or “low-fat” with the implication that this is healthy for you. Instead of the natural fat of dairy , you have now been convinced to eat a form of dairy that has been highly processed, depleted of most nutrients and full of sugar and unrefined carbohydrates. To make up for the fat calories which might have left you more satiated without sharp peaks in blood glucose, you can substitute a whole panoply of sugary materials, chocolate, candies, or fruit.
It turns out that when the best epidemiological studies are examined in this area, the evidence suggests a protective effect of dairy on heart disease risk. Dr. Peter Elwood, a highly respected epidemiologist at the University of Wales, has consistently pointed this out based on his and other researchers’ studies.
To quote Elwood, the best epidemiological studies are “prospective cohort studies, based on data for individual subjects within a single community, with detailed attention given to confounding” variables. Such studies “give a much better basis for the examination of independent associations between food items and disease incidence than studies based on either ecological data or relationships with risk factors.”
In 2004, Elwood published a review of such studies which was published in the European Journal of Clinical nutrition. He found 10 studies worthy of inclusion. All but one study suggested that milk protects against heart disease. Those subjects consuming the most milk were less likely to have a heart attack or stroke than those consuming no milk. The relative risk for high volume milk drinkers versus those drinking no milk for “ischaemic heart disease” (this refers to coronary artery disease , the major cause of heart attacks) was 0.87. In other words, if you drank a lot of milk you were 13% less likely to have heart disease than if you drank none.
Elwood’s original research on this was called the Caerphilly Prospective Study. Between 1979 and 1983, 2500 men completed a food frequency questionnaire. During the following 21 years, the relative risk in men who drank more than a pint of milk per day, compared with the risk in men who drank no milk was 0.66 for ischemic heart disease and 0.84 for ischaemic stroke. In other words, high milk drinkers were 34% less likely to develop coronary heart disease, the major cause heart attacks.
All the studies reviewed were set up at times when reduced-fat milk was unavailable or scarce therefore the conclusion from the best available evidence in 2004 should have been that full fat dairy lowers your risk of heart attack and stroke.
For both the general public and for my cardiac patients I, therefore, differ strongly in my advice regarding dairy consumption from most published dietary guidelines. Keeping in mind that “all things in moderation” applies just as much in this area as any other, I advise full fat dairy consumption. This means that they can consume butter, milk, full-fat cheese and yogurt. I strongly advise utilizing dairy that comes from grass-fed , pasture-raised cows for reasons I will examine in subsequent posts. Each of these dairy products has a different fatty acid profile and therefore, likely a different effect on cholesterol profiles. Butter, in particular, may warrant separating out from the other dairy products because it is a very highly concentrated fat. However, since reviewing the published data on butter consumption and cardiovascular disease, I have personally gone back to fairly liberally applying butter (again, hopefully from grass-fed, pasture-raised cows) to a lot of my foods because there are few data suggesting that butter raises my risk of cardiovascular disease and the stuff tastes awesome.