NutritionEd:

I found a very interesting article the other day in the Globe and Mail regarding satiety. It is well established now that protein in food provides more satiation during eating than the other macronutrients (CHO and FAT). What is interesting about this article is that researchers found a certain type of fat, oleic acic, appears to also have a satiating effect.

In a study involving lab mice, the researchers found that when oleic acid reaches the small intestine it is converted into a hormone called oleoylethanolamide, or OEA. This hormone, in turn, sends hunger-dampening signals to the brain. That means you can go longer without eating.

I find this very interesting as I had learned in school that Fat, overall, was low on the satiety totem pole. (that sensation of feeling “full” after consuming a fatty meal is likely the protein rather than the fat… or simply nausea.)

The possibility that certain fats are more satiating than others shouldn’t be surprising I suppose. Though the mechansim is signicantly different, carbs also have varying degrees of satiety.  ie: high fiber = full faster… hopefully everyone knows that by now!

So, could the dawn of the next food combining “craze” soon be upon us? Do you think the food industry will jump on research like this and, before you know it, we’ll be offered bizarre foods like Extra Virgin Olive Oil Protein Bars? Hmmmm, could be tasty.

Click here for the the Globe article or here for the paper’s abstract.

As discussed in my previous post, eggs are an amazing source of high quality protein. What they are also high in is cholesterol. Like many Canadians I bet your first thought is cholesterol = bad. But is it really a cause for concern? Is society’s perception well founded in that dietary cholesterol from eggs can lead to heart disease?

Ever since that fateful day in 1984, when Time Magazine published an article with this picture on the front cover, eggs have become synonymous with cholesterol. Unfortunately, as is often the case with media hype, articles such as this led society down a path of sweeping generalizations and unwarranted beliefs about eggs. Dietary cholesterol = risk of heart disease therefore eggs = risk of heart disease! Right? Wrong! The data from recent research on eggs indicates otherwise and the nutrition community has been trying to remove the misconceptions ever since.

Newsflash: Healthy* individuals eating up to 1 egg every day will not increase their risk of heart disease and stroke!

So what does increase the risk of heart disease and stroke if not dietary cholesterol?? The answer should come as no surprise to anyone for these two culprits have been very active in the media for many years; saturated and trans fat! High intakes of these fats in your diet have been implicated in raising the dreaded LDL cholesterol (mentioned here in one of my first posts). High levels of LDL in your blood correlate strongly with something called Atherosclerosis. (basically the build up of plaque in your arteries leading to narrowing or constricting of blood flow). Atherosclerosis is considered one form of heart disease.

Interestingly, some research is emerging that eggs may even play a role in treating heart disease! Egg protein has been shown to increase ones satiety after a meal and, therefore, facilitate weight loss; one of the principal features of heart disease management. Eggs are also nutrient dense in that for only a few calories you receive substantial amounts of vitamins, minerals, and other valuable nutrients such as choline, lutein & zeaxanthine.

Put simply, eggs truly are one of nature’s powerhouse foods.

* Note the word “healthy” individuals. If you have diabetes, heart disease, or currently have high cholesterol you may benefit from limiting cholesterol in your diet; including that from eggs.

1. Hu FB, Stampfer MJ, Rimm EB, et al. A prospective study of egg consumption and risk of cardiovascular disease in men and women. JAMA 1999;281:1387-1394.
2. Qureshi AI, Suri MF, Ahmed S, et al. Regular egg consumption does not increase the risk of stroke and cardiovascular diseases. Med Sci Monit 2007; 13(1):CR1-8

As I’m finishing up my degree in Dietetics with a rotation at the Canadian Egg Marketing Agency in Ottawa I figured it would be fun to write something interesting about, well, eggs! As most people probably know, eggs are synonymous with two things; protein and cholesterol. My first post on eggs will deal with protein.Eggs are often associated with the term, “High Quality” protein, but what does that mean? Here is a little summary:

Protein quality, from a nutrition perspective, is a term used to describe how well a protein from food matches the body’s requirements and, therefore, how useful the protein is for our body. This is determined by looking at the building blocks which make up the protein; called Amino Acids.

There are 20 primary amino acids, 9 of which our body cannot make on its own. These are considered “essential” and so must come from our diet. A protein’s quality is determined by asking the following questions:

1. Are all the 9 essential amino acids present in the protein?
2. Are the ratios of essential amino acids in the protein ideal?

The first question is answered fairly easily with a “yes”. In fact, pretty much every source of protein has at least some of all the essential amino acids. However, if the protein is deficient in 1 or more essential amino acid then it is considered incomplete. For your reference, grains are typically low in the amino acid lysine, while legumes are low in methionine. Animal products, on the other hand, are high in all the essential amino acids and are usually considered complete. (the exception being gelatin)

Answering the second question is a bit more complex. Basically, the body needs a certain proportion of essential amino acids in the protein in order for it to be used most effectively. If all 9 are present yet 1 or more are not very abundant then the protein is of lower quality because the body will not be able to use the protein to its fullest potential.

The “gold standard” used when determining protein quality is the egg (typically chicken egg). Eggs have all 9 essential amino acids in its protein and the ratios of these amino acids are very similar to the ideal protein needed by the body. You simply can’t find better protein in your diet than egg protein! As a result, egg protein is considered the #1 quality protein and all other proteins from all other food sources are compared against this standard.

References:

Whitney, E. N., Rolfes, S. R., (2004) Understanding Nutrition, Wadsworth Publishing; 10 edition
http://www.faqs.org/nutrition/Pre-Sma/Protein.html

http://en.wikipedia.org/wiki/Essential_amino_acids