T Nation

Egg Protein Digestibility Cooked vs Raw

this is pretty interesting…although its just one study…

Abstract:
Egg proteins contribute substantially to the daily nitrogen allowances in Western countries and are generally considered to be highly digestible. However, information is lacking on the true ileal digestibility of either raw or cooked egg protein.

The recent availability of stable isotope-labeled egg protein allowed determination of the true ileal digestibility of egg protein by means of noninvasive tracer techniques. Five ileostomy patients were studied, once after ingestion of a test meal consisting of 25 g of cooked 13C- and 15N-labeled egg protein, and once after ingestion of the same test meal in raw form. Ileal effluents and breath samples were collected at regular intervals after consumption of the test meal and analyzed for 15N- and 13C-content, respectively. The true ileal digestibility of cooked and raw egg protein amounted to 90.9 ± 0.8 and 51.3 ± 9.8%, respectively.

A significant negative correlation (r = -0.92, P < 0.001) was found between the 13C-recovery in breath and the recovery of exogenous N in the ileal effluents. In summary, using the 15N-dilution technique we demonstrated that the assimilation of cooked egg protein is efficient, albeit incomplete, and that the true ileal digestibility of egg protein is significantly enhanced by heat-pretreatment. A simple 13C-breath test technique furthermore proved to be a suitable alternative for the evaluation of the true ileal digestibility of egg protein.


and a couple other articles people might like…

BCAAs:

“BCAA supplementation before and after exercise has beneficial effects for decreasing exercise-induced muscle damage and promoting muscle-protein synthesis; this suggests the possibility that BCAAs are a useful supplement in relation to exercise and sports.”

high protein diets:

good info.thanks

So no raw eggs?

After reading the study, I don’t consider the conclusions to be significant.

One major flaw in the study design is the study size; the researchers only test 5 subjects in their study (4 women) and one of the subjects is at least 76 years old. That fact alone leads me to believe that the findings of this study are not significant nor relevant for the bodybuilding community.

Furthermore, the researchers gauged protein absorption by measuring the amount of radioactive labels that remained in the illeal effleunt (stool) in the patients.

For those without a science background, specific molecules in an oligonucleotide can be targeted and irradiated for labeling purposes. Basically, this technique provides researchers a non-invasive technique capable of tracking where specific compounds of interest end up within the body.

In this case, if only a small amount of the radioactively labeled protein is recovered within the illeal effleunt, it means that the majority of the ingested protein was absorbed by the body.

Converserly, if a large amount of radioactively labeled protein is recovered within the illeal effluecnt, it means that only a small amount of ingested protein was absorbed by the body.

Because this study calculates protein digestibility based on illeal effluent composition, it neglects the absorption that occurs within the large intestine (ascending, transverse, and descending colon).

Despite the fact that the majority of nutritionally relevant absorption occurs within the small intestine( where the illeum is), and the fact that the majority of the absorption that occurs within the large intestine involves water, not accounting for absorption within the large intestine still could potentially skew the results.

The researches themselves state: ‘However, because nitrogen is intensely metabolized, absorbed and secreted in the colon, fecal digestibility values do not necessarily equal ileal digestibility values.’

Given the study design and patient population, it would be impossible for the researchers to measure the amount of radioactively labeled protein recovered from the large intestine, because illeostomy patients have had their large intestines removed.

If the study size were expanded to included several hundred patients, and the methods were modified to included subjects with healthy, normal digestive tracts, then I would consider the findings to be significant.

Until a larger, improved study comes out, I’m going to keep drinking my raw liquid egg whites for breakfast with a smile on my face.

[quote]Big Aristotle wrote:
After reading the study, I don’t consider the conclusions to be significant.

One major flaw in the study design is the study size; the researchers only test 5 subjects in their study (4 women) and one of the subjects is at least 76 years old. That fact alone leads me to believe that the findings of this study are not significant nor relevant for the bodybuilding community.

Furthermore, the researchers gauged protein absorption by measuring the amount of radioactive labels that remained in the illeal effleunt (stool) in the patients.

For those without a science background, specific molecules in an oligonucleotide can be targeted and irradiated for labeling purposes. Basically, this technique provides researchers a non-invasive technique capable of tracking where specific compounds of interest end up within the body.

In this case, if only a small amount of the radioactively labeled protein is recovered within the illeal effleunt, it means that the majority of the ingested protein was absorbed by the body.

Converserly, if a large amount of radioactively labeled protein is recovered within the illeal effluecnt, it means that only a small amount of ingested protein was absorbed by the body.

Because this study calculates protein digestibility based on illeal effluent composition, it neglects the absorption that occurs within the large intestine (ascending, transverse, and descending colon).

Despite the fact that the majority of nutritionally relevant absorption occurs within the small intestine( where the illeum is), and the fact that the majority of the absorption that occurs within the large intestine involves water, not accounting for absorption within the large intestine still could potentially skew the results.

The researches themselves state: ‘However, because nitrogen is intensely metabolized, absorbed and secreted in the colon, fecal digestibility values do not necessarily equal ileal digestibility values.’

Given the study design and patient population, it would be impossible for the researchers to measure the amount of radioactively labeled protein recovered from the large intestine, because illeostomy patients have had their large intestines removed.

If the study size were expanded to included several hundred patients, and the methods were modified to included subjects with healthy, normal digestive tracts, then I would consider the findings to be significant.

Until a larger, improved study comes out, I’m going to keep drinking my raw liquid egg whites for breakfast with a smile on my face.

[/quote]

WHEW!!! that was a lot…but very good! thanks…ya its just one study like i said…but i wanted to throw it out there and see what people would say…did you read the other articles by any chance?