Tuesday, February 8, 2011

What Do We Know About Nutrition? Are Eggs Bad for You?

So Elaine Magee, who has written thirty five books on nutrition, posted: Nobody Needs a Six Egg Omelet.  Several readers pointed out that the cholesterol in eggs was the good, HDL, kind.  How did someone who posts on WebMD and has written that many books on nutrition miss this obvious fact?

The truth is, we can't even agree if eggs are good or bad.  I've posted the latest medline battle below.  Looks like both sides are determined they are right.  The take home message for the layman?  The experts don't know what they're doing.  Even the ones that WebMD has anointed as our nutrition gurus. 

Are Eggs Bad For You?




Can J Cardiol. 2010 Nov;26(9):e336-9.

Dietary cholesterol and egg yolks: not for patients at risk of vascular disease.

Spence JD, Jenkins DJ, Davignon J.

Stroke Prevention & Atheroschlerosis Research Centre, Robarts Research Institute, London, Ontario. dspence@robarts.ca

Abstract

A widespread misconception has been developing among the Canadian public and among physicians. It is increasingly believed that consumption of dietary cholesterol and egg yolks is harmless. There are good reasons for long- standing recommendations that dietary cholesterol should be limited to less than 200 mg/day; a single large egg yolk contains approximately 275 mg of cholesterol (more than a day's worth of cholesterol). Although some studies showed no harm from consumption of eggs in healthy people, this outcome may have been due to lack of power to detect clinically relevant increases in a low-risk population. Moreover, the same studies showed that among participants who became diabetic during observation, consumption of one egg a day doubled their risk compared with less than one egg a week. Diet is not just about fasting cholesterol; it is mainly about the postprandial effects of cholesterol, saturated fats, oxidative stress and inflammation. A misplaced focus on fasting lipids obscures three key issues. Dietary cholesterol increases the susceptibility of low-density lipoprotein to oxidation, increases postprandial lipemia and potentiates the adverse effects of dietary saturated fat. Dietary cholesterol, including egg yolks, is harmful to the arteries. Patients at risk of cardiovascular disease should limit their intake of cholesterol. Stopping the consumption of egg yolks after a stroke or myocardial infarction would be like quitting smoking after a diagnosis of lung cancer: a necessary action, but late. The evidence presented in the current review suggests that the widespread perception among the public and health care professionals that dietary cholesterol is benign is misplaced, and that improved education is needed to correct this misconception.

PMID: 21076725

Arch Latinoam Nutr. 2006 Dec;56(4):315-20.

[Egg: concepts, analyses and controversies in the human health].

[Article in Spanish]

Novello D, Franceschini P, Quintiliano DA, Ost PR.

Universidade Estadual do Centro-Oeste-PR, Brasil.

Abstract

Cholesterol rich-foods consumption has been related as a causing factor for heart ischemic disease. Because the high cholesterol content of the yolk, the egg consumption has been decreased in spite of it, egg is a complete food, rich in many nutrients, and economically accessible. The cholesterol content in egg yolk has also important properties for the human organism. The present work had the objective to review the scientific literature about egg's cholesterol, describing the possible consequences on the human health and wellbeing, its effect when they are enriched, and the chemical composition in relation to its lipidic profile. Information for this review was collected through national and international inquiries. According to this information, most of the studies on egg consumption are not related to the risk of cardiopathies in healthy people. Also, in people with diabetes mellitus, there is scarce evidence to drawn any conclusion about egg consumption and cardiopathies. Omega-3 egg enrichment presumably possesses a protective effect against cancer, despite its cholesterol content remains unaltered. Many of the Food Chemical Composition Tables contain different values on egg's fat composition, so it should be continuously update to reduce these discrepancies. Also, more studies on omega-3 enriched eggs are necessary for deeper conclusions on their cardio-protective effect.

PMID: 17425175

J Med Assoc Thai. 2008 Mar;91(3):400-7.

High-density lipoprotein cholesterol changes after continuous egg consumption in healthy adults.

Mayurasakorn K, Srisura W, Sitphahul P, Hongto PO.

Department of Social Medicine, Samutsakhon General Hospital, Samutsakhon 74000, Thailand. drkorapat@hotmail.com

Abstract

OBJECTIVE: To determine the relationship between continuous egg consumption with Thai life-style dietary and serum lipids of healthy young people.

MATERIAL AND METHOD: Fifty-six participants with an average age of 35 were enrolled. In an experimental method of cholesterol intake, all participants were fed an additional egg per day to their basic diet. This project ran for 12 weeks.

RESULTS: The 12-week egg consumption significantly increased serum total cholesterol by 0.27 +/- 0.15 mmol/L (10.43 +/- 5.80 mg/dL) (p < 0.05). The HDL-cholesterol (HDL-c) increased significant by 0.55 +/- 0.06 mmol/L (21.80 +/- 2.25 mg/dL) (p < 0.001) while the total cholesterol (TC) decreased as the HDL-c ratio was 0.94 +/- 1.1 (p < 0.001). No significant changes were found in LDL-cholesterol (LDL-c) and triglyceride levels. The present study showed that small serum LDL-c changed in response to change of egg consumption. Additionally, 12-week egg consumption also resulted in an increasing HDL-c level.

CONCLUSION: In the majority of healthy adults, an addition of one egg per day to a normal fat diet could raise HDL-c levels and decreased the ratio of TC toHDL-c. Therefore, egg consumption might benefit blood cholesterol.

PMID: 18575296



2 comments:

  1. Great food for thought Christopher.

    Also of note is that the Spence article ties the increase in DM to the egg consumption, which is not founded. However the connection between high blood sugar and increased cholesterol is well documented. Take home...eat the egg, leave the toast.
    Evan Fleischmann, ND

    ReplyDelete
  2. Eggs are definitely good for dieting. If you plan to build muscles, protein food like eggs, tuna and lean meat are important. You have to be healthy while dieting, you should take lorna vanderhaeghe.

    ReplyDelete