Eggs: Antioxidant Powerhouses


The last time I wrote about eggs I was defending them against spurious comments in the press saying they’re “worse than a KFC Double-Down.” If you don’t have time to check that piece out, I’ll summarize: Eggs are not worse for you than any fast food sandwich; on the contrary they’re really, really good for you; don’t be silly.

Eggs are a great source of concentrated nutrition including vitamins B12, D, A, folate, phosphorous, riboflavin (B2), protein, vitamin K and selenium. They’re also a good source of choline, needed for building your cell walls. They’re not just little bundles of bad cholesterol (check out that last link if this statement shocks you).

Now researchers at the University of Alberta have discovered eggs also contain antioxidant properties, which may actually help in the prevention of cardiovascular disease and cancer. Published in the peer-reviewed journal Food Chemistry, graduate students in Agricultural Food and Nutritional Science at the university took a look at egg yolks produced by hens fed typical chicken diets (primarily wheat or corn) and found the yolks contained high levels of two amino acids — tryptophan and tyrosine. Amino acids are the building blocks of proteins and these two amino acids happen to have high antioxidant properties.

So the researchers set about determining the antioxidant properties of the yolks. They found the yolks of two eggs, in their raw state, provide the same antioxidant level as 25 grams of cranberries (which would be about 2250 on the ORAC scale, by my own calculations). They say that’s about twice the antioxidant value of an apple. In other words, pretty impressive antioxidant values.

But, here’s the catch: Once the egg yolks were cooked, their antioxidant levels dropped by about half. That’s still pretty good, of course. If two yolks were twice as good as an apple, dropping them to half would make them as good as an apple.

Some people are a bit squeamish about eating egg yolks raw, although I’m not one of them, provided the eggs are from healthy, free-roaming chickens that weren’t pumped full of drugs and were allowed to forage for their natural diet. Those who are squeamish often don’t realize that every time they’re eating mayonnaise or a traditionally made caesar salad, they’re eating raw egg yolk.

But I’m thinking you can still maximize your antioxidant levels by keeping your yolks runny when you cook your eggs. Have them sunny-side up or over-easy instead of scrambled or hard-boiled, if you want to keep your antioxidant protection intact. (This wasn’t shown in the experiment and is something the researchers plan on studying in the future. For now I think my suggestion is a pretty safe bet.) But even if you don’t like your yolks runny, it’s good to know you’re still getting some antioxidant protection from the unfairly maligned eggs.

The researchers feel the tyrosine and tryptophan may only be the beginning of the antioxidants in egg yolks. “Ultimately, we’re trying to map antioxidants in egg yolks so we have to look at all of the properties in the yolks that could contain antioxidants, as well as how the eggs are ingested,” says researcher Jianping Wu.

Wu previously did research on eggs finding their protein is converted by enzymes in the digestive tract to produce peptides which act in the same way as prescriptions drugs are used to lower high blood pressure. Rather ironic, since eggs were previously thought to be bad for blood pressure due of their cholesterol content.

The Healthy Foodie is Doug DiPasquale, Holistic Nutritionist and trained chef, living in Toronto.
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