Eggs, Heart Disease and Diabetes – Dreams of an Omelette

It was early Sunday morning. Mr. Mason watched his wife across the kitchen table. She appeared deeply engaged in the daily crossword puzzle. He swallowed his three diabetes pills with a large sip of orange juice.

There was a momentary sparkle of light, a glint of sunshine through the clouds. He would give it another try.

19176030_m

“I’m told that a highly prestigious nutrition journal published a paper recently showing that eating eggs is fine if you have diabetes. So, maybe I should have my omelette today.”

She raised her chin just enough to be able to stare at him over her reading glasses.

“William dear. We finished this discussion fifty years ago. The American Heart Association hasn’t changed its mind. You should thank me for not letting you eat all that pipe plugging cholesterol you seem to fantasize about all the time.”

A momentary silence. He wasn’t giving up. “But, that didn’t prevent me from getting diabetes though.”

“C’mon. You know as well as I do that if you’d eaten all those fats, your belly would be twice the size it is today, and it surely’s big enough. So don’t start that nonsense all over.

“Dreams of an Omelet.”

A book that never leaves my night drawer is The Lost Art of Healing by Bernard Lown, a respected Boston cardiologist, and Nobel Piece Price Recipient.

In his book, doctor Lown shortly describes his relationship with a certain Mr. H., “a schoolteacher in his mid-fifties, gentle thoughtful and undemanding.” Mr. H. suffered from a heart valve disorder and needed regular check-ups. This was many years ago when dietary cholesterol was much more dreaded than today.

Surprisingly, with many things to be concerned bout, he was culturally in tune by worrying about his cholesterol. Although he was free of risk factors for coronary heart disease, and his arteries were normal, he was on a rigorous low-animal-fat diet. “My wife is very strict with me; she makes sure that not a crumb of cholesterol passes my lips.”

When I saw him at Christmas, I asked what he would wish for most in the new year. Without hesitation, he responded, as though the thought had long been percolating, “I dream of an omelet”. He continued, “I have not had an omelet for ten years. My wife tells me it is poison for me because of my heart condition”.

I explained that his type of heart problem does not require rigorous avoidance of cholesterol. “As a matter of fact, I am now prescribing an omelet for you once a week, always on Sunday”. To make sure that his wife would believe the incredible, a cardiologist prescribing an omelet, I wrote a letter accompanying the prescription of a two-egg omelet once weekly. When he next visited, he was beaming. “I look forward to Sunday as never before.” His eyes lit up. “Doctor, it is the best gift I have had in a very long time.” 

                                                               The Los Art of Healing – Bernard Lown

However, William Mason’s cardiologist didn’t prescribe omelets.

Although eggs had been cleared by many specialists, research still suggested they might be harmful to diabetics.

advertisement

Eggs, Cholesterol and Heart Disease – Are We Done?

In 1989, a paper by Stamler and co-workers in The Lancet presenting data from a study of 1824 middle-aged men who were followed for 25 years, concluded that intake of dietary cholesterol increased the risk of death, particularly death from cardiovascular disease (1).

These data strengthened the belief that dietary cholesterol causes heart disease and should be avoided as much as possible. For the omelette, this was the final nail in the coffin.

In a 2000 revision of the American Heart Association (AHA) dietary guidelines (2) the message was pretty clear: “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.”

For the layperson, this wasn’t too hard to understand. If cholesterol causes heart disease, eating it doesn’t make sense. So eliminating eggs from our dishes didn’t need much convincing.

With more than 200 mg of cholesterol in each egg yolk, eggs were branded as unhealthy and were to be eaten sparingly.

In the 1940’s U.S. per capita, egg consumption averaged more than 400 eggs a year but dropped to an average of 236 in the 1990s. The primary culprit for this reduction in egg consumption is believed to have been the concern for the impact dietary cholesterol might have on blood cholesterol levels and the incidence of heart disease (3).

But the landscape has changed. Recent observational data suggest that egg consumption is not associated with risk of cardiovascular disease and mortality from heart disease in the general population. These conclusions are largely based on two systematic reviews and meta-analyses published 2013 (3,4).

However, both of these studies left doubts with regards to diabetes.

One of the studies suggested egg consumption may be associated with an increased risk of coronary heart disease among diabetic patients. The other study hinted that egg consumption may be associated with a raised incidence of type 2 diabetes among the general population, and increased cardiovascular risk among diabetic patients.

However, it was pointed out that people with high egg consumption were not following current dietary guidelines and thus more likely to have an unhealthy lifestyle in general.

So, in 2013 eggs were okay if you didn’t have diabetes. Not good enough for Mr. Mason and his omelette dream.

Eggs and Diabetes

Mr. Mason’s recent glint of hope has to do with a paper published in the current issue of the American Journal of Clinical Nutrition (5).

The authors of the paper hypothesize that “people with type 2 diabetes may benefit from egg consumption because eggs are a nutritious and convenient way of improving protein and micronutrient contents of the diet, which have importance for satiety and weight management.” 

The study performed in Sydney, Australia, randomized 140 participants to either a high-egg diet or a low egg diet. The former were instructed to eat 2 eggs/d at breakfast for 6 d/wk (12 eggs/wk), the latter were instructed to consume less than 2 eggs/wk.

After 12 weeks, there was no significant difference between the groups for blood levels of total cholesterol, LDL-cholesterol (the bad cholesterol), HDL-cholesterol (the good cholesterol), triglyceride or blood sugar control.

The high-egg group reported less hunger and greater satiety following breakfast.

The authors conclude that a high-egg diet can be included safely as a part of the dietary management of type 2 diabetes.

However, the study results are approached much more carefully by Peter M Clifton who writes an accompanying editorial in the same journal. After also citing a few other studies, Clifton concludes; “Given these data and the fact that coronary risk is not fully captured by fasting lipids, caution is needed in recommending daily egg consumption in people with type 2 diabetes.”

Interestingly, the issue of eggs and diabetes was recently addressed in another paper published on-line in the American Journal of Clinical Nutrition by Finnish investigators who studied the association between egg consumption and risk of type 2 diabetes in middle-aged and older men from eastern Finland (6).

This was a typical prospective cohort study that included 2,332 men aged 42–60 years participating in the population-based Kuopio Ischemic Heart Disease Risk Factor Study.

During an average follow-up of 19.3 years (after adjustment for potential confounders), those in the highest vs. the lowest egg intake quartile had a 38% lower risk of developing type 2 diabetes. Thus, higher egg intake was associated with a lower risk of type 2 diabetes in this cohort of middle-aged and older men.

Dear Mr. Mason …

Eggs have a high nutritional value. Although they are rich in cholesterol, the total amount of fat is not high (5.2 g). This fat is predominantly unsaturated (51% monounsaturated and 16% polyunsaturated).

The high protein content of eggs improves satiety. Eating eggs will probably reduce the risk of consuming energy dense, less nutritious alternatives.

Epidemiological studies suggest that high egg consumption is not associated with cardiovascular disease in the general population.

Recent evidence shows that high egg consumption does not affect blood cholesterol or other blood lipids in a negative way in patients with diabetes.

A recent Finnish study even suggests that high egg consumption may reduce the risk of type 2 diabetes among middle-aged and older men.

Still, US guidelines for diabetics recommend less than four eggs a week, unfortunately not allowing for many omelets (7). But, if you decide to visit or move to the UK, there are no limits with regards to egg consumption (8).

Anyway, I’m happy to go along with Dr. Bernard Lown and write you and Mrs. Mason a prescription for an omelette (or two).

advertisement

0 0 vote
Article Rating
Subscribe
Notify of
guest

This site uses Akismet to reduce spam. Learn how your comment data is processed.

35 Comments
Oldest
Newest Most Voted
Inline Feedbacks
View all comments
Share386
Tweet
Share3