Tuesday, 13 January 2009

As sure as Eggs is Eggs.....

...is grammatically incorrect! Rumour has it that it's a corruption of "As sure as x = x". But anyway....

Eggs are very nutritious and should be eaten freely as part of a healthy diet.

Click http://www.nutritiondata.com/facts/dairy-and-egg-products/111/2 and set the serving size to 1 large (50g) to see what nutrients there are in a raw whole egg.

Click http://www.nutritiondata.com/facts/dairy-and-egg-products/112/2 and set the serving size to 1 large (33g) to see what nutrients there are in a raw egg white.

Click http://www.nutritiondata.com/facts/dairy-and-egg-products/113/2 and set serving size to 1 large (17g) to see what nutrients there are in a raw egg yolk.

The amino acid scores for whole egg , white and yolk are 136, 145 and 146 respectively. Eggs are a good source of complete proteins. This is because the yolk and white need to contain everything necessary for a growing chick embryo.

Can I drink eggs raw to save time?There are three potential problems with this:

1) Salmonella poisoning. Unless you’re pretty sure of the hens that the eggs came from, there is a risk of poisoning from raw eggs. This doesn’t apply to pasteurised eggs from suppliers like http://www.eggnation.co.uk/ for example.

2) Poor absorption of egg white protein. According to http://jn.nutrition.org/cgi/content/full/128/10/1716 , only 51% of raw egg white protein is absorbed during digestion compared to 91% for cooked egg white protein. According to http://ajpgi.physiology.org/cgi/content/full/277/5/G935 , the figures are 65% and 94% respectively. The second study used 200g of white and one yolk. I don’t believe that there is a problem with the absorption of raw egg yolk, though problem 1 still remains. Pasteurised egg white protein is well absorbed.

3) Poor biotin absorption. Raw egg white contains a glycoprotein called avidin which binds to biotin (Vit. B7) in the yolk and prevents its absorption. Cooking or pasteurisation denatures (changes the 3-D structure of) the avidin and renders it harmless.

What about all that cholesterol in egg yolks?

Current “Healthy Eating” guidelines state that we should eat no more than 3 egg yolks/whole eggs per week. This is based on the erroneous assumption that dietary cholesterol always increases serum cholesterol and that this is always a bad thing. According to Effect of dietary egg on human serum cholesterol and triglycerides, adding or not adding 500mg of dietary cholesterol from two large eggs per day made no significant difference to serum cholesterol or triglycerides in 116 healthy male subjects. Some went up and some went down. Eddie Vos at http://www.health-heart.org/cholesterol.htm reckons that you’d have to eat 20 whole eggs per day to get as much dietary cholesterol as the liver produces each day (5g). Egg yolks do contain some fat and this should be factored into your total diet. If you happen to have the genes for familial hypercholesterolaemia, then you need to keep a close eye on dietary cholesterol intake. See also Eat Whole Eggs All Day and Throw Your Statins Away? 375x Increased Dietary Cholesterol Intake From Eggs Reduces Visceral Fat & Promotes Healthy Cholesterol Metabolism.

There is a problem with modern eggs though, and it’s caused by the food that’s fed to the hens. Grains contain about 50 times more Linoleic acid (omega-6) than Alpha-Linolenic acid (omega-3) and this raises the omega-6:omega-3 ratio of the eggs that the hens lay. Hens eating a natural diet of bugs, grubs and vegetation lay eggs with a 1:1 ratio of omega-6:omega-3, but grain-fed hens lay eggs with an omega-6:omega-3 ratio of >10:1. A high omega-6:omega-3 ratio in the diet is associated with increased risk factors for heart disease, cancer and Insulin Resistance (pre-type 2 diabetes). Therefore, if large numbers of cheapo eggs are eaten, it’s advisable to eat other foods that are rich in omega-3 fats.


Daniel Herman said...

Hit it straight on. That's why I buy more expensive "omega 3 fortified" eggs for my whole eggs, and cheapo Costco eggs to use for egg whites only.

At least I think it's doing something to help combat that problem.

Rosso said...

Fancy givin' this a try Nige?


You can even name the hens after people on Muscletalk.

Nigel Kinbrum B.Sc.(Hons) Eng said...

I think I'll stick to virtual animals, thanks! I have a virtual kitten called Nigeepoo on Facebook. :-)