4

votes

Egg yolk consumption increases atherosclerosis risk and plaque build up?

Answered on August 19, 2014
Created August 14, 2012 at 12:38 PM

This was posted at sciencedaily the other day. Thoughts?

http://www.sciencedaily.com/releases/2012/08/120813155640.htm ScienceDaily (Aug. 13, 2012) ??? Newly published research led by Western's Dr. David Spence shows that eating egg yolks accelerates atherosclerosis in a manner similar to smoking cigarettes.

Surveying more than 1200 patients, Spence found regular consumption of egg yolks is about two-thirds as bad as smoking when it comes to increased build-up of carotid plaque, a risk factor for stroke and heart attack. The research is published online in the journal Atherosclerosis.

Atherosclerosis, also called coronary artery disease, is a disorder of the arteries where plaques, aggravated by cholesterol, form on the inner arterial wall. Plaque rupture is the usual cause of most heart attacks and many strokes.

The study looked at data from 1,231 men and women, with a mean age of 61.5, who were patients attending vascular prevention clinics at London Health Sciences Centre's University Hospital. Ultrasound was used to establish a measurement of total plaque area and questionnaires were filled out regarding their lifestyle and medications including pack-years of smoking (number of packs per day of cigarettes times the number of years), and the number of egg yolks consumed per week times the number of years consumed (egg yolk-years).

The researchers found carotid plaque area increased linearly with age after age 40, but increased exponentially with pack-years of smoking and egg yolk-years. In other words, compared to age, both tobacco smoking and egg yolk consumption accelerate atherosclerosis. The study also found those eating three or more yolks a week had significantly more plaque area than those who ate two or fewer yolks per week.

"The mantra 'eggs can be part of a healthy diet for healthy people' has confused the issue. It has been known for a long time that a high cholesterol intake increases the risk of cardiovascular events, and egg yolks have a very high cholesterol content. In diabetics, an egg a day increases coronary risk by two to five-fold," said Spence, a professor of Neurology at Western's Schulich School of Medicine & Dentistry and the director of its Stroke Prevention and Atherosclerosis Research Centre at the Robarts Research Institute.

"What we have shown is that with aging, plaque builds up gradually in the arteries of Canadians, and egg yolks make it build up faster -- about two-thirds as much as smoking. In the long haul, egg yolks are not okay for most Canadians."

Spence added the effect of egg yolk consumption over time on increasing the amount of plaque in the arteries was independent of sex, cholesterol, blood pressure, smoking, body mass index and diabetes. And while he says more research should be done to take in possible confounders such as exercise and waist circumference, he stresses that regular consumption of egg yolk should be avoided by persons at risk of cardiovascular disease.

Egg yolk consumption and carotid plaque

Abstract

Background Increasingly the potential harm from high cholesterol intake, and specifically from egg yolks, is considered insignificant. We therefore assessed total plaque area (TPA) in patients attending Canadian vascular prevention clinics to determine if the atherosclerosis burden, as a marker of arterial damage, was related to egg intake. To provide perspective on the magnitude of the effect, we also analysed the effect of smoking (pack-years).

Methods Consecutive patients attending vascular prevention clinics at University Hospital had baseline measurement of TPA by duplex ultrasound, and filled out questionnaires regarding their lifestyle and medications, including pack-years of smoking, and the number of egg yolks consumed per week times the number of years consumed (egg-yolk years).

Results Data were available in 1262 patients; mean (SD) age was 61.5 (14.8) years; 47% were women. Carotid plaque area increased linearly with age after age 40, but increased exponentially with pack-years of smoking and with egg-yolk years. Plaque area in patients consuming <2 eggs per week (n = 388) was 125 ?? 129 mm2, versus 132 ?? 142 mm2 in those consuming 3 or more eggs per week (n = 603); (p < 0.0001 after adjustment for age). In multiple regression, egg-yolk years remained significant after adjusting for coronary risk factors.

Interpretation Our findings suggest that regular consumption of egg yolk should be avoided by persons at risk of cardiovascular disease. This hypothesis should be tested in a prospective study with more detailed information about diet, and other possible confounders such as exercise and waist circumference.

http://www.sciencedirect.com/science/article/pii/S0021915012005047

Ef26f888ed248de197c37a4cb04ef4a7

(584)

on August 20, 2012
at 08:10 AM

haha. That is pretty funny

8508fec4bae4a580d1e1b807058fee8e

(6244)

on August 19, 2012
at 01:41 AM

hysterically funny article ToddB!

6eb2812b40855ba64508cbf2dc48f1b6

(2119)

on August 15, 2012
at 04:17 PM

I regret that I have only one point to give.

61844af1187e745e09bb394cbd28cf23

(11058)

on August 15, 2012
at 02:30 PM

That gave me a good laugh. Thanks!

A7768b6c6be7f5d6acc76e5efa66464c

on August 15, 2012
at 03:21 AM

Nicely said, Ryan, and pithy!

1c67bc28f4e44bbb8770b86df0463df3

(6719)

on August 15, 2012
at 01:21 AM

You know its funny, every thoughtful post I put up, the more attitude, the more 100 points I get.

D7cc4049bef85d1979efbd853dc07c8e

(4029)

on August 14, 2012
at 11:25 PM

+1 Bravo! Even got a Robb Wolf linkage to it.

Bb3d1772b28c02da2426e40dfcb533f5

(5381)

on August 14, 2012
at 11:06 PM

Plantgirl, I cant hugely be bothered doing a search right now (sorry), but as I understand it the liver makes cholesterol, but it does so with a feedback mechanism, so if you get lots from your diet (ie you already have some), it stops making it.

Ecb90bbbd5a15868b2592d517a4a5e82

(280)

on August 14, 2012
at 07:53 PM

Filled out questionnaires? Just another correlation based questionnaire bit of junk. Wouldn't waste my time with this.

A1a7413b99e03bc77f02d95c4170ea43

(2393)

on August 14, 2012
at 06:47 PM

Just successfully defended his Ph.D, actually! We were told at AHS this year. So he's full on now. :)

D7cc4049bef85d1979efbd853dc07c8e

(4029)

on August 14, 2012
at 06:32 PM

And dieting causes people to be overweight after scientific survey found people who were on a diet were more likely to be overweight than the average person. Believe it!

Bf57bcbdc19d4f1728599053acd020ab

(5043)

on August 14, 2012
at 06:31 PM

Calling DENISE MINGER!! We need you! TAKE DOWN THIS STUDY PLEASE!!

D7cc4049bef85d1979efbd853dc07c8e

(4029)

on August 14, 2012
at 06:29 PM

Tom naughton's YouTube video "science for smart people" does a good number on reading these things.

D7cc4049bef85d1979efbd853dc07c8e

(4029)

on August 14, 2012
at 06:27 PM

"Ignore the Awkward" it's a great book, check it out from a library. Or better, buy it.

785efa3950951957e65fa17efb25b078

(452)

on August 14, 2012
at 06:09 PM

Most of the research/writeups is done by this guy: https://twitter.com/#!/Silverhydra

61844af1187e745e09bb394cbd28cf23

(11058)

on August 14, 2012
at 06:08 PM

Good thing you don't get to decide what others find useful then, Harfatum.

A968087cc1dd66d480749c02e4619ef4

(20436)

on August 14, 2012
at 05:57 PM

Who runs that Examine.com website? It is pretty cool!

7767e05a8c4504f6be03f13ee40815cd

(1299)

on August 14, 2012
at 05:47 PM

"I don't like this, and am going to ignore it" would also be thoughts, but not useful to anyone who wants to understand the issue. Jamie's answer is closer to what I'd hope we're looking for here.

785efa3950951957e65fa17efb25b078

(452)

on August 14, 2012
at 05:30 PM

Not to mention saturated fat is okay too: http://examine.com/faq/is-saturated-fat-bad-for-me.html

1edb06ded9ccf098a4517ca4a7a34ebc

(14952)

on August 14, 2012
at 05:23 PM

if it were indeed known for so long, why even bother asking people about it anymore?

61844af1187e745e09bb394cbd28cf23

(11058)

on August 14, 2012
at 04:46 PM

and grains. The next headline will read "Egg Yolk Consumption Causes Fragile Bones" after they survey 1000 people with leg fractures and ask what they ate for breakfast.

0a9ad4e577fe24a6b8aafa1dd7a50c79

(5150)

on August 14, 2012
at 04:17 PM

^^Read up on what fructose does to the liver

0a9ad4e577fe24a6b8aafa1dd7a50c79

(5150)

on August 14, 2012
at 04:17 PM

^^Read up on whats fructose does

0a9ad4e577fe24a6b8aafa1dd7a50c79

(5150)

on August 14, 2012
at 04:17 PM

^Read up on what the liver does

C0c839648b31512515daaffe8e4e9ad1

(468)

on August 14, 2012
at 03:40 PM

I would like to see some primary sources also that say cholesterol doesn't come from food. Thanks.

F0e558010a2ecb31fa37b7c491596b8e

(3850)

on August 14, 2012
at 02:53 PM

As far as I can see, the question was "Thoughts?" That's his answer.

7767e05a8c4504f6be03f13ee40815cd

(1299)

on August 14, 2012
at 02:29 PM

I agree with this, but it is not an answer.

A1a7413b99e03bc77f02d95c4170ea43

(2393)

on August 14, 2012
at 01:12 PM

Yeah, same old regurgitated shit. Didn't give it a second thought.

  • Ef26f888ed248de197c37a4cb04ef4a7

    asked by

    (584)
  • Views
    6.8K
  • Last Activity
    1281D AGO
Frontpage book

Get FREE instant access to our Paleo For Beginners Guide & 15 FREE Recipes!

18 Answers

11
1c67bc28f4e44bbb8770b86df0463df3

on August 14, 2012
at 12:55 PM

"It has been known for a long time that a high cholesterol intake increases the risk of cardiovascular events"

Blatant lie.

A1a7413b99e03bc77f02d95c4170ea43

(2393)

on August 14, 2012
at 01:12 PM

Yeah, same old regurgitated shit. Didn't give it a second thought.

1c67bc28f4e44bbb8770b86df0463df3

(6719)

on August 15, 2012
at 01:21 AM

You know its funny, every thoughtful post I put up, the more attitude, the more 100 points I get.

61844af1187e745e09bb394cbd28cf23

(11058)

on August 14, 2012
at 06:08 PM

Good thing you don't get to decide what others find useful then, Harfatum.

F0e558010a2ecb31fa37b7c491596b8e

(3850)

on August 14, 2012
at 02:53 PM

As far as I can see, the question was "Thoughts?" That's his answer.

7767e05a8c4504f6be03f13ee40815cd

(1299)

on August 14, 2012
at 02:29 PM

I agree with this, but it is not an answer.

1edb06ded9ccf098a4517ca4a7a34ebc

(14952)

on August 14, 2012
at 05:23 PM

if it were indeed known for so long, why even bother asking people about it anymore?

7767e05a8c4504f6be03f13ee40815cd

(1299)

on August 14, 2012
at 05:47 PM

"I don't like this, and am going to ignore it" would also be thoughts, but not useful to anyone who wants to understand the issue. Jamie's answer is closer to what I'd hope we're looking for here.

785efa3950951957e65fa17efb25b078

(452)

on August 14, 2012
at 05:30 PM

Not to mention saturated fat is okay too: http://examine.com/faq/is-saturated-fat-bad-for-me.html

9
41b6d083b81b00421749cae74b0211c7

on August 14, 2012
at 07:45 PM

I'm a PhD student at NC State studying diet and genetics.

I just broke down this study and exposed it's shortcomings. Check it out on my blog: http://understandnutrition.blogspot.com/

D7cc4049bef85d1979efbd853dc07c8e

(4029)

on August 14, 2012
at 11:25 PM

+1 Bravo! Even got a Robb Wolf linkage to it.

8
A968087cc1dd66d480749c02e4619ef4

(20436)

on August 14, 2012
at 02:53 PM

Epidemiology. Food frequency questionaires. Need I say more? Yes, this is a biased crap study.

We live in a society that thinks eggs are bad for you - especially the yolks. Are people who eat a lot of egg yolks the type of people to be concerned about health? Possibly not. Maybe they are the type of people to eat a lot of other crap as well. I can pretty much guarantee that nobody in that study was eating anywhere near paleo.

Chris Masterjohn knows a crapload about cholesterol and heart disease. For anyone who hasn't crawled out from under a internet rock, he is getting a PhD in cholesterol biochemistry. Chris says eggs are good eatin'. Especially the yolks. That's good enough for me.

Edit:

Mark Sisson just did a robust takedown of this study. Thought I should add the link:

http://www.marksdailyapple.com/are-eggs-really-as-bad-for-your-arteries-as-cigarettes/#axzz23iaN64F6

A1a7413b99e03bc77f02d95c4170ea43

(2393)

on August 14, 2012
at 06:47 PM

Just successfully defended his Ph.D, actually! We were told at AHS this year. So he's full on now. :)

7
Cf416725f639ffd1bb90764792ce7b8a

(2799)

on August 14, 2012
at 01:19 PM

Meaningless study, they ignore hydrogenated oil.

D7cc4049bef85d1979efbd853dc07c8e

(4029)

on August 14, 2012
at 06:32 PM

And dieting causes people to be overweight after scientific survey found people who were on a diet were more likely to be overweight than the average person. Believe it!

61844af1187e745e09bb394cbd28cf23

(11058)

on August 14, 2012
at 04:46 PM

and grains. The next headline will read "Egg Yolk Consumption Causes Fragile Bones" after they survey 1000 people with leg fractures and ask what they ate for breakfast.

6
Bb3d1772b28c02da2426e40dfcb533f5

(5381)

on August 14, 2012
at 02:20 PM

My thoughts are study = correlation.

You know what else is a correlation. Rain dances. Dance + rain = dancing causes rain. In psychology we refer to that as superstition. When people dont understand things, or cant control them, they tend to rely on it, instead of reason.

I thought had already been established that dietary cholesterol doesnt turn into blood cholesterol, tho? (Am I right?)

Either way, there needs to be some proposed mechanism via which the LDL becomes oxidised, produces plaque etc. Without a mechanistic explaination, all the mainstream heart disease talk is hot air. Just having lots of LDL, when normal LDL itself doesnt cause artery plaque, isnt a satifactory glossing over of the facts.

When the mainstream view delivers a satifactory mechanistic explaination for all these assertions about the dangers of high LDL, and the "protective effects" of HDL regarding the still not well understood phenomena of heart disease, I might start listening to their ramblings. Once they have a full and total explaination ie "a hypothesis" they can test it in animal studies.

  1. Make a hypothesis (Ie an actual fraking hypothesis about how something works, not just like dancing and rain and shizz)
  2. Test the hypothesis thoroughly, attempting to prove it both right and more importantly WRONG.
  3. Call this science when your done with it. Instead of simply calling everything science, just because you used statistics.

Until then its a bit like alchemy, or brain drilling, or measuring the width of your skull etc...

I would really love to "prove" a stastical link between umbrellas and lung cancer or something weird, just to freak people out :P

Its reasonably , sorta clear heart disease has some strong association with small dense LDL, which as an explaination makes some sense. If you add to that picture the clear and obvious factor of inflammation, which increase with stress, and you have yourself a semi-decent sounding theory - IMO.

Ie - high carbs & sugars + low fat + lots a stress etc = small dense LDL pinging thru your artery wall ie heart disease (Add in lots o-6 oils because they are inflammatory, and a lack of o-3 from salmon and grassfed meats)

People do seem to get heart attacks when they are stressed. And theres no doubt that people are getting them more now people eat less fat, more sugar, more carbs and more vegetable oil just like these stupid people told them to.

Not that I eat alot of eggs these days, I am currently restricting iodine. Egg yolks are pretty high in iodine.

0a9ad4e577fe24a6b8aafa1dd7a50c79

(5150)

on August 14, 2012
at 04:17 PM

^Read up on what the liver does

0a9ad4e577fe24a6b8aafa1dd7a50c79

(5150)

on August 14, 2012
at 04:17 PM

^^Read up on what fructose does to the liver

D7cc4049bef85d1979efbd853dc07c8e

(4029)

on August 14, 2012
at 06:27 PM

"Ignore the Awkward" it's a great book, check it out from a library. Or better, buy it.

C0c839648b31512515daaffe8e4e9ad1

(468)

on August 14, 2012
at 03:40 PM

I would like to see some primary sources also that say cholesterol doesn't come from food. Thanks.

0a9ad4e577fe24a6b8aafa1dd7a50c79

(5150)

on August 14, 2012
at 04:17 PM

^^Read up on whats fructose does

Bb3d1772b28c02da2426e40dfcb533f5

(5381)

on August 14, 2012
at 11:06 PM

Plantgirl, I cant hugely be bothered doing a search right now (sorry), but as I understand it the liver makes cholesterol, but it does so with a feedback mechanism, so if you get lots from your diet (ie you already have some), it stops making it.

4
0b4326a4949718451a8571b82558dc10

on August 14, 2012
at 06:09 PM

I guarantee people who eat egg whites instead of whole eggs aren't sitting on the couch all Sunday downing wings, bread, beer, and watching football...

people eat egg whites because they think they're more healthy. These people are much more likely to get their asses off the couch. Same with whole grains...If you eat whole grains instead of white bread chances are you give a shit and have an overall healthy lifestyle.

6eb2812b40855ba64508cbf2dc48f1b6

(2119)

on August 15, 2012
at 04:17 PM

I regret that I have only one point to give.

A7768b6c6be7f5d6acc76e5efa66464c

on August 15, 2012
at 03:21 AM

Nicely said, Ryan, and pithy!

4
Baa413654789b57f3579474ca7fa43d7

(2349)

on August 14, 2012
at 05:43 PM

I think you could add this study to these other very convincing examples of correlation and causation:

http://www.businessweek.com/magazine/correlation-or-causation-12012011-gfx.html

"Is this Mountain Range Affecting the Murder Rate?"

61844af1187e745e09bb394cbd28cf23

(11058)

on August 15, 2012
at 02:30 PM

That gave me a good laugh. Thanks!

8508fec4bae4a580d1e1b807058fee8e

(6244)

on August 19, 2012
at 01:41 AM

hysterically funny article ToddB!

4
Dc6407193ba441d1438f6f0c06af872b

on August 14, 2012
at 03:49 PM

And men who shave live longer. (But shaving has nothing to do with it -- it's the kind of person who shaves versus the kind of person who doesn't)

And women who took hormone replacement therapy in the 80s had 40% fewer heart attacks, controlling for age, smoking, etc. (But in double-blind experiments in the 90s, hormone replacement therapy lead to an increase in heart attacks. Apparently the kind of woman who got therapy was the kind of woman who otherwise took care of herself, and so the net result was greater health, even though the therapy itself was harmful to cardiovascular health.)

And your odds of drowning are much higher if you've eaten ice cream in the last 24 hours. (Summertime!)


Correlation is not causation. I'm not saying eggs aren't bad for you, just that this study doesn't prove it. It could well be that people who eat eggs are people who otherwise tend to ignore doctor's advice and participate in unhealthful activities. Or maybe eggs tend to be cooked in unhealthful oils. Or maybe eggs are unhealthful. Now that this intriguing question has been raised, hopefully these researchers will follow up with a study that can give more definitive results.

2
Af3e3615beba642bcafd0f21d64d74f7

on August 14, 2012
at 10:25 PM

Believe the study, more eggs for me.

2
Bf57bcbdc19d4f1728599053acd020ab

(5043)

on August 14, 2012
at 06:29 PM

"In multiple regression, egg-yolk years remained significant after adjusting for coronary risk factors."

Apparently they mean by "coronary risk factors" things like high blood pressure, high cholestorol levels, smoking, being overweight and diabetic. I They do mention that exercise and waist circumference are not considered, however, which I find confusing. They claim the negative effect of the "egg-yolk years" effect is independent of the other risk factors. I find that hard to believe.

I call it uncalled for to give dietary advice based on such a limited correlation study. Particularly this outrageous claim: "In diabetics, an egg a day increases coronary risk by two to five-fold," said Spence"

Good grief. That's fear-mongering.

2
785efa3950951957e65fa17efb25b078

(452)

on August 14, 2012
at 03:21 PM

Best link on eggs, and what they are/aren't:

Are eggs healthy?

785efa3950951957e65fa17efb25b078

(452)

on August 14, 2012
at 06:09 PM

Most of the research/writeups is done by this guy: https://twitter.com/#!/Silverhydra

A968087cc1dd66d480749c02e4619ef4

(20436)

on August 14, 2012
at 05:57 PM

Who runs that Examine.com website? It is pretty cool!

2
A7768b6c6be7f5d6acc76e5efa66464c

on August 14, 2012
at 03:19 PM

This should become an FAQ about reading reportage of studies of food and disease: if the report doesn't tell us What did they eat?, we cannot even draw correlations, never mind infering causation. When I say What did they eat?, I mean everything. just saying someone ate 3 egg yolks tells us almost nothing meaningful. And there is more to health than diet. They tell us some people smoked, but what else do they know about the health and habits of the respondents?

So, what about all the other foods they ate besides the eggs? Most people eating a standard American diet eat eggs as part of breakfast. American breakfast usually or often includes bread, biscuits, pancakes, waffles, pastries, or other cereals. Did the study separate those who ate eggs without the cereals from those who ate both? What about vegetable oils?

Another thing about these studies is that they rely on questionnaires. Can you remember what you ate (including portion size) a week ago? How about a month? A year ago? Do you remember with enough detail and accuracy that you would make important decisions based on those data? Yeah--me either. Unless people could a) be trusted not to fib; b) to log all their food during the study; and c) the researchers accounted for all confounders, including the other foods, then we cannot derive conclusions from this.

Also, the researcher quoted who said "What we have shown...." is full of shit and should go back to school to re-learn how studies work. At the very least, he should read the Wikipedia entry on epidemiological studies.

D7cc4049bef85d1979efbd853dc07c8e

(4029)

on August 14, 2012
at 06:29 PM

Tom naughton's YouTube video "science for smart people" does a good number on reading these things.

1
1edb06ded9ccf098a4517ca4a7a34ebc

on August 30, 2012
at 11:50 AM

http://nhregister.com/articles/2012/08/26/opinion/doc503acdac86207461915202.txt?viewmode=fullstory

The study is fully debunked in the above link. I found it a very quick and worthwhile read.

1
0a9ad4e577fe24a6b8aafa1dd7a50c79

on August 14, 2012
at 04:51 PM

So whole eggs have no association with heart disease or cardiovascular health issues but egg yolks do? Yeah, I don't think so.

Ef26f888ed248de197c37a4cb04ef4a7

(584)

on August 20, 2012
at 08:10 AM

haha. That is pretty funny

0
877ded1787562057ee2e1a4548b6050a

on August 16, 2012
at 02:17 PM

This is very simple to resolve. Just follow Paleo/Primal dieters for several years and see what happens. We all eat plenty of whole eggs to make it a valid study.

0
3846a3b61bc9051e4baebdef62e58c52

(18635)

on August 14, 2012
at 07:10 PM

I'll just sit on my pins and needles waiting for this study :

"This hypothesis should be tested in a prospective study with more detailed information about diet, and other possible confounders such as exercise and waist circumference."

0
1edb06ded9ccf098a4517ca4a7a34ebc

on August 14, 2012
at 05:06 PM

Too many potential confounds. The study provided is only preliminary, and even the authors conclude that it is inadequate to draw any conclusions from, stating "This hypothesis should be tested in a prospective study with more detailed information about diet, and other possible confounders such as exercise and waist circumference."

Here's a clinical study comparing blood lipids and glycemic control on type 2 diabetics following a calorie restricted high protein diet vs a calorie restricted high protein, high cholesterol (whole eggs included) diet. Both groups showed improvements, but the latter, high cholesterol group even more so. http://www.ncbi.nlm.nih.gov/pubmed/21134328

Answer Question


Get FREE instant access to our
Paleo For Beginners Guide & 15 FREE Recipes!