Editor's note: This post references research covered in full on 鶹ý. For another opinion on the Chinese study, see The Methods Man blog by F. Perry Wilson, MD.
The Skeptical Cardiologist that there was no good evidence supporting limiting dietary cholesterol to 300 mg per day. I , therefore, in 2016, when this long-standing dietary recommendation came out of the U.S. dietary guidelines.
Recognizing that dietary cholesterol doesn't need to be limited means that .
Egg Whites: A Product of Nutritional Misinformation?
Why, then do egg whites continue to be created and consumed?
On a regular basis, patients tell me that they are eating egg white omelets because they believe egg yolks are not heart healthy.
Old, bad nutritional dogma takes a long time to reverse apparently. To this day, for example, the National Lipid Association still limiting daily cholesterol consumption to <200 mg/day
Therefore I find it necessary to highlight additional new studies that further eggsonerate eggs.
To wit, I shall briefly discuss two articles that were published last month and brought to my attention by friends and readers who are aware of my rabid support for the egg.
Article One: The Wonderfully-Acronymed DIABEGG Study
Entitled "Effect of a high-egg diet on cardiometabolic risk factors in people with type 2 diabetes: the Diabetes and Egg (DIABEGG) Study -- randomized weight-loss and follow-up phase," our , published in The American Journal of Clinical Nutrition, was performed in Australia at the Sydney Medical School. Investigators randomized 128 patients with prediabetes or type 2 diabetes (T2D) to a high-egg or low-egg diet:
Throughout all study phases, including the 3-mo weight-loss phase, participants consuming the high-egg diet were instructed to eat 2 eggs/d at breakfast for 6 d/wk (12 eggs/wk). Those in the low-egg group were directed to consume <2 eggs/wk, and to match the protein intake that the high-egg group had consumed at breakfast with 10 g lean animal protein (meat, chicken, or fish) or other protein-rich alternatives, such as legumes and reduced-fat dairy products (also consumed at breakfast). Recommended egg-cooking methods were boiled or poached, but they could also be fried if a polyunsaturated cooking oil, such as olive oil, was used. The prescribed diets were energy and macronutrient matched, as reported previously. At the end of 12 months, both groups had lost about 3 kg in weight.
The investigators measured everything they could to look at diabetic and cardiometabolic biomarkers that might suggest adverse effects of egg eating on the cardiovascular system, but they could find no difference between the egg eaters and the non-egg eaters.
High egg consumption had no adverse effects on the following factors that are felt to be important in the development of atherosclerosis:
- measures of systemic and vascular inflammation (high sensitivity C-reactive protein, IL-6, soluble E-selectin)
- oxidative stress, the adipokine adiponectin (which also modulates insulin resistance)
- glycemia (fasting plasma glucose, glycated hemoglobin, and a medium-term measure of glycemia, 1,5-anhydroglucitol)
The authors suggested that nutritional guidelines stop worrying about limiting eggs.
Article Two: Half A Million Chinese Can't Be Wrong
This observational , published in Heart, found that egg consumption in a huge Chinese population was associated with less stroke, and major cardiac events (MCE):
Compared with non-consumers, daily egg consumption was associated with lower risk of CVD (HR 0.89, 95% CI 0.87 to 0.92). Corresponding multivariate-adjusted HRs (95% CI) for IHD, MCE, haemorrhagic stroke, and ischaemic stroke were 0.88 (0.84 to 0.93), 0.86 (0.76 to 0.97), 0.74 (0.67 to 0.82) and 0.90 (0.85 to 0.95), respectively. There were significant dose-response relationships of egg consumption with morbidity of all CVD endpoints (P for linear trend <0.05). Daily consumers also had an 18% lower risk of CVD death and a 28% lower risk of haemorrhagic stroke death compared to non-consumers.
The lower risk for stroke and cardiovascular death in egg eaters persisted after accounting for known CVD risk factors.
(And yes, I agree this is an observational study, which we should take with huge grains of salt and pepper).
Are EGG Whites the Skim Milk Scam of the Egg Industry?
I've written about the scam that is , but it occurs to me that egg white consumption is equally nonsensical.
What happens to the wonderfully nutritious yolk of the egg when it is brutally separated from its white? It is put in a container and sold as liquid egg yolk. Makers of mayonnaise are big consumers of liquid egg yolk.
Thus, like dairy farmers who double their sales by selling skim milk and its dairy fat separately, egg producers are probably delighted that Americans are consuming egg whites, allowing them to get two products from a single egg.
As I wrote previously, not everyone is an egg lover and I'm fine with that. There is no evidence that you have to eat them. You could feel towards them as did Alfred Hitchcock, quoted as saying: "I'm frightened of eggs -- worse than frightened; they revolt me. That white round thing without any holes ... have you ever seen anything more revolting than an egg yolk breaking and spilling its yellow liquid? Blood is jolly, red. But egg yolk is yellow, revolting. I've never tasted it."
For those who don't find yellow revolting, however, avoiding egg yolk makes no nutritional sense.
, is a private practice noninvasive cardiologist and medical director of echocardiography at St. Luke's Hospital in St. Louis. He blogs on nutrition, cardiac testing, quackery, and other things worthy of skepticism at , where a version of this post first appeared.