`Want Healthier Eggs? Feed Hens EVOO - Olive Oil Times

Want Healthier Eggs? Feed Hens EVOO

Mar. 30, 2015
Sukhsatej Batra

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Eggs are a break­fast sta­ple for most peo­ple. Although an excel­lent source of pro­tein, peo­ple with high cho­les­terol lev­els, heart dis­ease or dia­betes often avoid eat­ing eggs because high cho­les­terol con­tent of egg yolk is believed to raise blood cho­les­terol lev­els.

So what if eggs could be lower in sat­u­rated fat and cho­les­terol? Several stud­ies con­ducted on fat intake of hens have shown that the type of dietary fat influ­ences lipid com­po­si­tion of egg yolks. In one such study, hens fed soy­bean oil had egg yolks with a higher con­tent of omega‑6 polyun­sat­u­rated fatty acids; while those fed lin­seed oil had a higher con­tent of omega‑3 polyun­sat­u­rated fatty acids.

Based on results of past stud­ies and the fact that polyphe­nols in extra vir­gin olive oil pro­vide pro­tec­tion against heart dis­ease, researchers at the University of Bari’Aldo Moro’ in Italy decided to include EVOO in the diets of lay­ing hens to deter­mine if it would influ­ence egg qual­ity.

The study, pub­lished in the February 2015 issue of the jour­nal Lipids in Health and Disease, eval­u­ated the effects of dietary sup­ple­men­ta­tion of hen feed with EVOO from two dif­fer­ent olive cul­ti­vars with dif­fer­ent polyphe­nol con­tent on egg qual­ity and egg yolk cho­les­terol.

In a first of its kind study, researchers divided 150 lay­ing hens into three groups and fed them a nor­mal wheat and soy­bean meal that dif­fered only in the source of oil for 10 weeks.


All feeds con­tained 2.5 per­cent of oil as either sun­flower oil for the con­trol or first group; EVOO with low polyphe­nol con­tent of 38 mg/kg from the Cima di Bitonto vari­ety for the sec­ond group; and EVOO that con­tained a high con­tent of polyphe­nols of 254 mg/kg from the Coratina vari­ety for the third group of hens.

Egg lay­ing rate, egg weight and egg shell qual­ity were sim­i­lar in hens of all three groups. The amount of polyphe­nols in the feed, how­ever, was found to influ­ence egg yolk color score, which was low­est in eggs from hens fed sun­flower oil and high­est in eggs from hens fed EVOO with high polyphe­nol con­tent.

Similarly, hens fed high polyphe­nol EVOO laid eggs that had lower total yolk cho­les­terol lev­els than hens fed low polyphe­nol EVOO. The total cho­les­terol con­tent of egg yolk decreased by 4.04 per­cent in hens fed low polyphe­nol EVOO, while it decreased by 6.74 per­cent in hens fed high polyphe­nol EVOO when com­pared to cho­les­terol lev­els in egg yolks from the con­trol group.

Additionally, eggs from the high polyphe­nol EVOO group had lower sat­u­rated fatty acids, higher polyun­sat­u­rated fatty acids and a bet­ter sat­u­rated to unsat­u­rated fatty acid ratio than con­ven­tional eggs. The athero­genic index also decreased as the con­tent of polyphe­nol of the diet increased — 0.77 in egg yolks of hens fed the high polyphe­nol EVOO diet, 0.86 in egg yolk of hens fed low polyphe­nol EVOO and 1.09 in the con­trol group.

Findings of this inves­ti­ga­tion indi­cate that feed­ing lay­ing hens a diet that includes polyphe­nol-rich EVOO could lead to the pro­duc­tion of eggs that have lower cho­les­terol con­tent and a bet­ter fatty acid pro­file as com­pared to con­ven­tional eggs. According to the authors of the study, such health­ier eggs could be ben­e­fi­cial for human health.

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