August 19, 2012
Is eating egg yolks as bad as smoking?
From CNN:
A new study suggests eating egg yolks can accelerate heart disease almost as much as smoking. The study published online in the journal Atherosclerosis found eating egg yolks regularly increases plaque buildup about two-thirds as much as smoking does. Specifically, patients who ate three or more yolks a week showed significantly more plaque than those who ate two or less yolks per week. It may seem harsh to compare smoking with eating egg yolks, but lead study author Dr. David Spence says researchers needed a way to put it into perspective since both eating cholesterol and smoking increase cardiovascular risks - but the general public believes smoking is far worse for your health. The issue is with the yolk, not the egg, says Spence, who is also a professor of neurology at the University of Western Ontario's Schulich School of Medicine & Dentistry. "One jumbo chicken egg yolk has about 237 milligrams of cholesterol." Keeping a diet low in cholesterol is key, says Spence. Even if you are young and healthy, eating egg yolks can increase the risk of cardiovascular diseases later. "Just because you are 20 doesn't mean egg yolks aren't going to cause any trouble down the line," he says.
Study: Egg yolk nearly as bad as smoking
For those patients with increased coronary risk, such as diabetics, eating an egg yolk a day can increase coronary risk by two to five-fold, he adds. Atherosclerosis, also called coronary artery disease, occurs when plaque builds up in the blood vessels leading to the heart, specifically the inner arterial wall, and limits the amount of blood that can pass through.
More here.
Posted by Azra Raza at 07:00 AM | Permalink
Comments
This study was so poorly conducted that it's a joke. Not even close to 3QD's usual standard.
Posted by: Mike | Aug 19, 2012 7:15:12 AM
The NHS Choices website has a section devoted to evaluating the science behind prominent health stories in the media.
Here's the page for this one:
http://www.nhs.uk/news/2012/08august/Pages/Eating-egg-yolks-as-bad-as-smoking.aspx
Posted by: Ella | Aug 19, 2012 9:45:50 AM
Thanks for the useful link, Ella.
Posted by: Bryon | Aug 19, 2012 3:05:26 PM
I believe this is the study that was critiqued at some length by Dr Steve Novella in the latest 'Skeptics Guide to the Universe' podcast, released yesterday. He too was very critical of the study, which goes against other recent research in this field.
Posted by: Stewart Henderson | Aug 19, 2012 11:25:40 PM
Because I work for people who need medically special diets, I read an AWFUL lot of stuff like this -- not about eggs but about specific foods that need close attention to be either useful to my clients or off their list. I am not a scientist but I can distinguish a well designed study from one that was carried out in the absence of sufficient controls.
So. To reach the conclusions these people did, and be credible, you would need to have relied not at all on self-reporting, and to have closely supervised the entire diets of the subjects for the duration of the study. And you would have to make sure eggs were just about the only source of dietary cholesterol or animal protein during the same period, too. Then you would need a control group who took in a precise amount of dietary cholesterol from sources that were anything BUT eggs. Having done that, you could then see the difference between eggs and red meat, for instance. Would there be anything to compare? That would be interesting.
When you take snapshots of unhealthy behaviors occurring together -- smoking, drinking, a highly careless approach to food involving excess dietary cholesterol -- you are going to find people who, in their late 40s, will start to have medical trouble of many kinds. How harmful each behavior is, in the presence of the others, is very hard to determine. Just look at all the people who say smoking helps them not to overeat -- they may have lower cholesterol than their overweight peers who don't smoke. But you don't conclude from that that smoking reduces cholesterol, do you?
Finally, who funded this study? If you followed the money, it might lead you to the makers of Egg-beaters or another producer of egg whites-only from a carton.
Posted by: Elatia Harris | Aug 20, 2012 12:14:53 AM
Causation does not equal correlation: "In addition to relying completely on the recollection of patients as to what they ate, the study did not account for waist circumference and it did not account for a patient's exercise program. And perhaps most notably, it only looked at patients with existing cardiovascular issues."
Did this doctor take statistics?
Posted by: Tim K. | Aug 20, 2012 8:18:13 AM
The headline "Egg yolks 2/3'rds as bad as smoking if smoking didn't increase the risks of lung cancer, throat cancer, mouth cancer, emphysema, wasn't addictive, didn't complicate pregnancy and didn't contain any toxic chemicals but did provide some important nutrients." just isn't very catchy. Not to mention there isn't much of a problem with second hand yolk.
Posted by: sneu | Aug 20, 2012 4:45:55 PM
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