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Charcoal reduces cholesterol in eggs

Hens get modified feed and produce healthier eggs

Hens raised at the São Paulo State University (Unesp) at Jaboticabal are producing healthier eggs for people to eat. The technology developed by professor Pedro Alves de Souza, of the Agrarian and Veterinary Science Faculty (FCAV), consists of adding a small quantity of charcoal residues to the feed – the same kind you use in barbecue grills. It  has achieved the best rate ever gotten in research into cholesterol reduction based on a poultry diet. A simple, cheap, and, natural solution that reduced the cholesterol count in poultry meat by 34%, increased height by 2.55% and lowered the number of cracked eggs by 27%.

Rich in cholesterol, contrary to poultry meat, eggs were for a long time considered an ally of hypercholesterolemia – excess cholesterol in the blood – a risk factor for the appearance of heart disease. A single egg, more precisely the yolk, contains an average of 200 mg of cholesterol. The daily ingestion control of this substance is of fundamental importance for those whose cholesterol level is above what doctor say is acceptable- 200 mg per deciliter – (a tenth of a liter)- and also for those who have diabetes.

In these cases, in order to avoid the level of cholesterol run out of control, doctors recommend a very strict diet, which means that the daily consumption of cholesterol must be capped at 200mg a day. This means that in eating just one egg, a person would have ingested his or her daily allowance, and could eat no other substance of animal origin during the day. In the opinion of cardiologist Jaqueline Scholz Issa, of the Heart Institute (Incor) of the Hospital das Clínicas of the School of Medicine of the University of São Paulo (USP), an egg with 22% less cholesterol, that is to say, with around 156 mg, is healthier and would allow people to eat another 44 mg of cholesterol, corresponding to, for example, around 100 gr. of fish such as salmon, tuna, or cod. “This may not seem much, but, in practice, for those obliged to follow a strict diet, it makes a lot of difference”, she says.

Besides reducing cholesterol in eggs, the researcher showed that the technique is still more efficient in the case of poultry meat: it lowered the cholesterol level by up to 34%. Although white meat is one the least problematic regarding cholesterol – 100 gr. of chicken breast has 75 mg of cholesterol, while the same quantity of lean red meat has 90 mg –, this reduction can also relieve the burden of restrictions imposed by the treatment.

More fertile – But the results of the research do not just benefit consumers. Adding charcoal residues to chicken feed also helps raise poultry more efficiently, improving the productivity of the birds and the strength of the eggshells. According to Souza, this is due to two factors. “First, we know that fertility is affected by high levels of fat. Therefore, it is natural to expect leaner hens to lay more eggs. Second, vegetable charcoal is very rich in calcium, which helps make the shell stronger”, she explains. To achieve these results, Souza fed the birds to a diet of corn, soybean meal, whole soybeans, meat flour, limestone, gravel, bi-calcium phosphate, a mixture of minerals and vitamins, amino acids, and a growth enhancing medication. To this mixture, she added between 1% and 3% of vegetable ash (charcoal residues from crushed eucalyptus). The diet with 1% of charcoal lowered the cholesterol by only 17% in eggs and 26% in the meat. With 2% of charcoal, the reduction rose to 21% in eggs and 29% in the meat. And the charcoal, emphasizes the researcher, “is a natural additive, rich in calcium, phosphorus, and potassium”.

The only side effect observed was a change in the consistency of the birds’ feces, which became drier because of the binding action of the charcoal. This is an advantage for breeders, since it makes it easier to remove waste from the barn and reduces the number of flies. In Souza’s opinion, the method is commercially viable: the total cost of feed would rise by around 2%.

Golden eggs
The eggs deriving from Souza’s research are quite different from other types of eggs sold under the label of light. These are sold at twice the price of ordinary eggs and, in the researcher’s opinion, it is merely a marketing stunt. She reached this conclusion after analyzing, last year, three samples of each of the various types sold at retail: the organically raised , the normal, the pufa, and the light.

In the FCAV’s Technology Laboratory for Products of Animal Origin, the total levels of cholesterol and lipids in all the samples were measured and compared. The results showed insignificant variations. For total lipids (fats) the concentrations ranged from 27.96 grams per 100 grams of yolk in organic eggs to 26.65 g/100 g in the light egg. With regard to cholesterol, the results were no less discouraging: 11.97 mg and 11.15 mg. The reduction in the amount of cholesterol in the light egg was just 6%, and not the 20% that the pack claimed.

The pufa type eggs had similar variations: 26.62 g/100 g of yolk in terms of total lipids and 1145 mg/100 g of yolk in cholesterol content. “The difference in cholesterol content between these eggs and normal eggs is insignificant. Being enriched with omega 3 type polyunsaturated fatty acids does not mean that they have less cholesterol, but rather that they contain a substance that may help the body eliminate cholesterol. Even so, we would have to assess whether they really do have omega 3 and how much”, she states.

The omega 3 family contains three fatty acids: linoleic acid, the main sources of which are soybean oil and rapeseed oil, eicosapentanoic acid-EPA and decosahexaenoic acid-DHA, found in saltwater fish oils. The way these fatty acids work (as well as polyunsaturated acids, there are the saturated and unsaturated ones) is still not fully known, but we do know they can reduce coagulation, and lower the level of triglycerides in the blood, and blood pressure. For this reason some food companies have begun adding omega 3 to products like eggs, milk, and bread, etc.

In the opinion of the doctor Raul Cavalcante Maranhão, director of Incor’s Lipids Laboratory, the benefits of these foods enriched with omega 3 is questionable, because the normal Brazilian diet, with high consumption of vegetable oil already contains the necessary amounts of these fatty acids.

The Brazilian Consumer Protection Institute (Idec), on learning of the research carried out at Unesp on light eggs, published information on the work in its monthly magazine, Consumidor S/A – Consumer Inc.-  warning consumers of misleading advertising in concerning these eggs. But in spite of the controversy raised with the publication of the results, they are still on supermarket shelves, some promising up to 40% less cholesterol, with the price of golden eggs.

After all, the important thing in controlling cholesterol is to avoid excess body weight and to lower the amount of fat in the diet, particularly saturated fat of animal. In spite of being rich in cholesterol, the advantage of eggs over the weekend barbecue is the small quality of fat they contain. Better still now that chicken breeders have the option producing eggs with less cholesterol.

The project
Lowering Cholesterol Levels in Eggs and Poultry Meat (nº 96/12620-6); Type Support for research project; Coordinator Pedro Alves de Souza – School of Agrarian and Veterinary Science at Unesp-Jaboticabal; Investment R$ 13,120.80