Blood is removed from meat before it is consumed. Below is, for example, how chickens are processed from Wikipedia.
- Removed from transport cages
- Hung by the legs on a shackle, mounted on a conveyor chain.
- Stunned using an electrically charged water bath
- Killed by cutting the blood vessels in the neck
- Bled so that most blood has left the carcass
- Scalded to soften the attachment of the feathers
- Plucked to remove the feathers
- Head removed
- Hock cutting to remove the feet
- Rehung in the evisceration room
- Gutted or eviscerated to remove the internal organs
- Washed to remove blood and soiling from the carcass
- Chilled to prevent bacterial spoiling
Why is the blood removed? Does it just simply taste bad? This might be a stupid question but being vegetarian, I may not know.
Blood finds use in many different dishes as well as biotechnological applications. Research-grade BSA (bovine serum albumin) is derived from cow's blood, there are not special facilities, same cows go for steaks and car seats. So part answer is economical: blood can be processed further. Also it is just easier not trying to preserve liquid inside vessel already opened by slitting the throat. It also seems that blood can rot faster than other tissues, maybe, because in dead animal immune responses are deteriorated and every infection in blood will activate.
I found a forensic article that states the following:
Because the protective agencies of the body are absent, the bacteria spread through the blood vessels using the proteins and carbohydrates of the blood as culture media.
I was unable to find anything more on this with my limited searching skill, though I plied it to the best.
There was an interesting study on the relation between decompostion of animal meat and the bacterial load though. It was a good read!
Human Biology Chapter 11 (Urinary)
*Excretion removes metabolic waste from the body while defecation removes undigested food and bacteria from the body.
*Urea is a by-product of amino acid metabolism.
excretion of metabolic wastes
maintenance of water-salt balance
maintenance of acid-base balance
maintenance of hemoglobin levels
*The urinary system does not regulate hemoglobin levels in the blood.
*This is another function of the kidneys. Vitamin D promotes calcium absorption from the digestive tract.
The kidneys filter and excrete H+ from the blood.
The kidneys produce H+ in the process of filtering the blood.
The blood has an acidic pH and the kidneys produce urine similar to the pH of the blood.
There is a high concentration of HCl acid in the urine producing an acidic substance.
*The kidneys remove and excrete excess H+ from the blood in order to maintain a blood pH of 7.4.
*Erythropoietin is a hormone secreted by the kidneys.
*The kidneys help to maintain blood pressure by monitoring the water-salt balance of the blood.
*The bladder will store urine until the urination reflex stimulates an individual to urinate. The kidneys produce the urine. The ureter transfers urine from the kidneys to the bladder. The renal pelvis acts as a funnel, transferring urine to the ureter. The urethra is the tube that releases urine to the outside of the body.
skeletal muscle and mucous membrane
mucous membrane and fibrous connective tissue
mucous membrane, smooth muscle, and fibrous connective tissue
skeletal muscle, fibrous connective tissue, and cartilage
*The three layers of the wall of a ureter are a mucous membrane, a smooth muscle layer, and a fibrous connective tissue.
Growth of Microorganisms in Meat | Microbiology
In this article we will discuss about the growth of microorganisms in meat.
Due to high moisture, rich in nitrogenous food, plentified supply of minerals and accessory growth factors usually has some fermentable carbohydrate (glycogen) and a favourable pH allows most of the microbes to grow.
The following factors influence the growth of microorganism:
(a) The kind and amount of contamination with microorganisms and the spread of these organisms in the meat,
(b) Physical properties of meat,
(c) Chemical properties of meat,
(d) Availability of oxygen, and
Fish and other Sea Food:
Various bacteria involved in the spoilage are part of the natural flora of the external slime of fishes and their intestinal contents. At higher temperature Micrococcus and Bacillus species involved in fish spoilage while at ordinary temperature, species of Escherichia, Proteus, Serratia, Sarcina and Clostridium are found.
Seafood includes fresh, frozen, dried, pickled and salted fish, as well as various shellfish. Fresh water fishes also get contamination from the surrounding microflora present in the water in which they live. The main genera that covers outer surfaces are: Pseudomonas, Alcaligenes, Micrococcus, Flavobacterium, Corynehacterium, Sarcina, Serratia, Vibrio, Salmonella and Bacillus species.
The presence of bacteria in the water content depends upon the temperature of water. Both psychrophiles and mesophiles are present in the water. Fresh water fish carry fresh water bacteria.
Boats, boxes, bins, fish ponds and fish houses including fisherman soon become heavily contami­nated with these bacteria and transfer them during cleaning. Most of the fishes pass large amount of water through their bodies pick up soil and water microorganism in this way, including pathogens if they are present.
The numbers of microorganisms on the skin of fish can be influenced by the method of catching. The other sources of contamination includes potatoes, spices and flavours used in fish cake. The microbial contents of fresh fish vary in the microbial fish products.
(i) Microbiology of Fish Brines:
The temperature of brine and salt concentration influences the bacterial activity. The kind and amount of bacteria also vary which result to fish spoilage. Contamination comes from the fish, which ordinarily introduces species of Pseudomonas, Alcali­genes and Flavobacterium. The continuous use of fish brine may contribute additional pathogens from successive lots of fish and because of salt tolerant bacteria (micrococci, etc.).
Autolysis, oxidation or bacterial activity spoil fish like meat. The fish flesh is autolysed more quickly due to the presence of fish enzymes and because of the less acid reaction of fish flesh that favours microbial growth.
Many of the fish oils seem to be more susceptible to oxida­tive deterioration than most animal fats. The lower the pH of fish flesh, the slower in general bacterial decomposi­tion. Lowering the pH of fish results from the conversion of muscle glycogen to lactic acid.
(iii) Factors Influencing Kind and Rate of Spoilage
(a) The kind of fish:
The various kinds of fish differ considerably in their perishability. Certain fatty fish deteriorate rapidly because of oxidation of unsaturated fats of their oils.
(b) The condition of fish when caught:
Fish full of food when caught, are more readily perishable than those with an empty intestinal tract.
(c) The kind and extent of contamination of the fish flesh with bacteria:
These may come from mud, water handlers, exterior slime, and the intestinal content of the fish and are supposed to enter the gill of the fish, from which they pass through the vascular system and thus invade the flesh, or to penetrate the intestinal tract and thus enter the body cavity.
In general, the greater the load of bacteria, the more rapid the spoilage. The contamination may take place in the net, in the fishing boat, on the docks, or later, in the plants. This process is accelerated by the digestive enzymes attacking and perforating the gut wall and viscera, which in themselves have a high rate of autolysis.
Bacterial growth is delayed at lower temperature. Cooling or chilling should be as rapid as possible 0 to -1°C. The high temperature reduce the life of fish. The prompt and rapid freezing of the fish is more effective in preservation.
(e) Use of an Antibiotic Ice or Dip:
Some antibiotics are recommended to avoid spoilage.
(iv) Characteristics of Spoilage:
The bright colours of fish fade and dirty, yellow-brown discolouration appear. The slime on the skin of fish increases, especially on the flaps and gills. The eyes gradually sink, and oh shrinkage the pupil becomes cloudy and the cornea opaque.
Flesh becomes soft and juice erodes when squeezed. The discolouration takes place towards tail due to oxidation of haemoglobin and the different types of odours evolved during spoilage and cooking will bring out these odours more strongly.
(v) Control of Spoiling Microorganisms:
Keeping microorganisms away from meats is called Asepsis. This process begins with avoidance from contamination. Before slaughtering, the animal should be carefully washed with water so as to remove dust from hair and hoof.
The knife may also introduce microorganism in the circulating blood. During evisceration contamination may come from the internal body parts like intestine, the air, the water, cloths, and brushes used on the carcass. Some organism may come from the surface soil and from workers.
Once meat is contaminated with microbes their removal is difficult. The use of hot water or sanitizer sprays under pressure is a procedure of decreasing the bacterial number. Moldy or spoiled portion of large piece of meat may be trimmed off.
Meats have been reported to have a shorter storage life in films with less permeable to water. Cured meats are packed in an oxygen- tight film with evacuation. It checks the growth of aerobes especially molds, reduces the rate of growth of staphylococci.
Canning of meat differs from product to product to be preserved. Most meat products are low-acid foods and are good culture media. Rates of heat penetration range from fairly effective in meat soups to very slow in tightly packed meats or in paste. Various additives such as spices, chemical salts and flavour also affect the heat processing. The process becomes more effective.
On the basis of heat processing, canned meat can be divided into two groups:
(a) Meat that are processed in one attempt (shelf-stable canned meat), and
(b) Meat that are heated enough to kill part of the spoilage organisms but must be kept refrigerated to prevent spoilage. This type of meat is known as non-shelf stable. The shelf-stable meat is processed at 98°C and the size of container is usually less than a kilogram. Cured meat temperature for processing should be 65°C and the container used during packing is of up to 22 kg.
Hot water treatment is also a method to remove the microbes from meat surfaces. But this may lessen nutrients and can damage colour. Heat applied during the smoking of meat and meat products helps in reducing microbes.
The cooking of meats for direct consumption greatly reduces the microbial content and hence lengthen the keeping time. Precooked frozen meat should contain few viable microbes. More meat is preserved by the use of low temperature either by chilling or freezing. Chilling is more common.
Meat can be preserved promptly and rapidly to temperature near freezing and chilling at only slightly above the freezing point. Meat may be held in chilling storage for a limited time with little change from their original constitution. Enzymatic and microbial changes in the foods are not prevented but are slowed down considerably. Cooler temperature prevents growth but slow metabolic activity may continue.
The storage time can be prolonged in an atmosphere containing added CO2 and O3. Ships equipped for storage of meat in a controlled atmosphere of CO2 have been employed successfully. Increasing amounts of CO2 inhibit microbial growth but also enhance the formation of met-myoglobin resulting into loss of colour. Storage time can be increased by the pressure of 2.5 to 3 ppm of ozone in the atmosphere.
Ozone is an active oxidizing agent, that may give an oxidized or tallowy flavour to fats. Few bacteria, molds and yeasts can grow in meats at low temperature are known as psychrotrophic bacteria (Sta­phylococcus, Alcaligenes, Micrococcus, Leuconostoc, Flavobacterium and Proteus).
(b) Freezing or Frozen Storage:
Under the usual conditions of storage of frozen foods microbial growth is prevented entirely and action of food enzymes is greatly retarded. The lower the storage temperature the slower will be any chemical or enzymatic reaction. The preservation of frozen meats is increasingly effective as the storage temperature drops from -12.2°C to -28.9°C.
The freezing process kills the bacteria. The rate of freezing of meat and other food items depends upon a number of factors, such as the temperature, circulation of air, or refrigerant, size and shape of package, kind of food etc. Sharp freezing refers to freezing in air with only natural air circulation or at best with electric fans. The freezing temperature is usually -23.3°C or lower but may vary from -15 to -29°C, and may take from 3 to 72 hours.
This is called slow freezing. Quick freezing is accomplished by one of the three methods:
(a) Direct immersion in a refrigerant,
(b) Indirect contact where the meat is in contact with the passage through which the refrigerant at -17.8 to -45.6°C flows, and
(c) Air-blast freezing where frigid air at -17.8 to -34.4°C is blown across the materials being frozen. Certain items now are being frozen into liquid nitrogen.
The advantages of quick freezing are:
(a) Smaller ice crystals formation and less destruction of intact cells of the food,
(b) A shorter period of sodification and therefore, less time for diffusion of soluble materials and for separation of ice,
(c) More prompt preservation of microbial growth, and
(d) More rapid enzyme action.
The ultraviolet rays serve to reduce number of microorganisms in the air and to inhibit or kill them on the surfaces of the meat reached directly by the rays. Irradiation also is used in the rapid aging of meats at higher than the usual chilling temperature to reduce the growth of microorganisms, especially molds, on the surface. Some oxidation, favoured by UV rays, and hydrolysis of fats may take place during aging.
Some types of sausages are preserved primarily by their dryness. In dried beef, made mostly from cured, smoked beef hams, growth of microorganism may take place before processing and may develop in the “pickle” during curing, but numbers of organism are reduced by the smoking and drying process.
Organisms may contaminate the dried ham during storage and the slices during cutting and packing. Salting and smoking are usually employed during meat drying.
Another method of drying pork involves a short addition of lecithin as an antioxidant and stabilizer. Drying may be in vacuum in trays, or by other methods. The meat for drying should be of good bacteriological quality.
Kosher Slaughter: An Introduction
My Jewish Learning is a not-for-profit and relies on your help
Once an animal considered acceptable for consumption has been slaughtered according to the prescribed method, there is still more to be done before the meat is considered kosher and fit to eat. This article covers only some of the provisions of the law in this area additional details may be found in Rabbi Appel&rsquos book and other written sources, but questions about specific instances should be directed to a competent rabbinic authority. It should be noted that in many cases kosher butchers have already done the salting and soaking required before meat is sold to a consumer. Reprinted, with permission from Ktav Publishing, from The Concise Code of Jewish Law, Volume 1.
Prohibition of Eating Blood
1. The blood of cattle, beasts, and fowl, whether of a clean or an unclean species, is forbidden, as it is written, &ldquoTherefore I said unto the children of Israel: No soul of you shall eat blood&hellip Ye shall not eat the blood of any flesh&hellip Whosoever eateth it shall be cut off&rdquo (Leviticus 17:12, 14). Apart from removing the veins and blood vessels, the blood must also be extracted from the meat through salting or broiling, as will be explained later.
Salting and Soaking of Meat
1. It is forbidden to cook meat that has not been koshered by salting it and drawing out the blood. However, before the meat is salted it must be thoroughly rinsed with water, and soaked entirely submerged in water for half an hour. All blood that is visible should be washed off the meat. In the case of fowl, the place where the incision was made in slaughtering it should be washed, and any blood visible inside the fowl must also be washed away. Lumps of coagulated blood resulting from a wound, that are sometimes found in cattle and fowl, must be cut away and removed before the meat is soaked. If the water is very cold, it should first be put in a warm place to take the chill out before the meat is soaked in it, because the cold water would harden the meat and the salt would then fail to draw out the blood.
2. If one forgot and allowed the meat to soak for twenty-four hours, the meat as well as the vessel in which it was soaked are forbidden and must not be used. If liver is soaked in water for twenty-four hours, a competent authority should be consulted.
3. On the eve of the Sabbath when there is not enough time, or on another occasion when one is pressed for time, it is sufficient to wash the meat thoroughly and to let it soak in water for a while, and when the water is clear of blood the meat may be salted.
4. If, after the soaking, a piece of meat is cut in two, the place of the incision must be thoroughly washed in order to rinse off any blood that may be there
5. Meat that is frozen must be thawed out before it is salted, but it should not be placed near a hot stove. In a case of emergency it may be soaked in lukewarm water.
6. The vessel that is used for soaking meat must not be used for any other purpose in connection with food.
7. After the meat has been soaked, the water must be drained off so that the salt will not be dissolved by the water and be ineffective in drawing out the blood. The meat should not be left to dry completely, so that the salt will not fall off.
8. The salt should not be as fine-grained as flour, because it would then immediately dissolve and fail to draw out the blood. Nor should it be too coarse, as it would then drop off the meat. The salt should be of medium size, and it should be dry so that it may be spread thoroughly over the meat.
9. The salt should be sprinkled on all sides of the meat so that no place is left unsalted. Poultry must therefore be properly opened so that it may be thoroughly salted on the inside as well.
10. The meat should remain in salt for one hour. In a case of emergency, it is sufficient for it to remain in salt for 24 minutes.
11. The meat that has been salted must be placed where the blood can readily drain off. Therefore, the draining basket should not be placed on the ground, because the blood will not be able to flow off easily. Even after the meat has remained in salt for the required period of time but has not yet been washed, it should not be placed where the blood cannot continue to flow freely. The draining board should be placed in a slanting position so that the blood will flow down freely. The board should not have any cavity where the briny fluid will accumulate. When salting poultry or the whole side of beef, it should be placed with the hollow part turned downward so that the blood may flow off freely.
12. After the meat has remained in salt for the required length of time, the salt should be shaken off well and the meat thoroughly washed off three times so that no blood remains. Meat which had been salted should not be placed in a vessel containing no water before it is washed off.
13. Meat which has not yet been washed should not be placed where there may be some salt there at times. A special vessel should be set aside for meat that has not yet been soaked and salted, and the vessel should not be used for vegetables or fruit or for any other food that is generally eaten without first being washed, as the blood from the meat will adhere to the vessel and then get on to the food.
14. Since the liver contains a great amount of blood, salting does not suffice, but it must be properly cut open across its length and width and placed with the rent part downward over the fire, so that the fire will draw out all of the blood. Before it is placed over the fire, the liver is washed and, when set for broiling, lightly salted. It must be broiled until it is edible, and then washed three times so that the blood is rinsed off. After that it may be cooked, if so desired.
15. Care should be taken to broil the liver over a flame and not in an oven from which the coals have been removed. The liver may not be broiled while wrapped in foil or paper of any kind, no matter how thin.
16. Liver must not be salted before it is broiled in the manner in which meat is salted, and it certainly should not be salted together with meat.
17. Meat that was kept for three full days (72 hours) and had not been soaked within that period of time, may not be cooked but must be broiled.
I’ve always pulled the dark red meat (brown, once cooked) out of fish before cooking it, if not after. It’s what some people call the blood line, the set of nerves that make up a fish’s lateral lines, and it’s often what gives fish that undesired fishy or earthy taste. Certain fish, like bluefish and tuna, contain more of it than others, while milder fish like snapper and cod have relatively thin blood lines (in the past, I haven’t bothered to remove theirs). But there’s another, more critical reason to remove this dark pungent layer: it could be poisonous.
Scombroid toxin is a bacteria-borne poison that occurs in the blood line of more oily fishes when they’re mishandled before consumption. These fish include (but are not limited to) tuna (all species), amberjack, bluefish, kahawai, sardines, herring, mackerel, wahoo and mahimahi, to list a few.
According to Charles Patrick Davis, MD, PhD on emedicine, symptoms vary from person to person, but common symptoms include nausea, diarrhea, vomiting, headaches, flushing, fever, hives, abdominal cramps, unusual heart-pounding sensations, and burning or itching in the mouth, which can last for up to a few days.
Like ciguatera, another toxin commonly found in fish (though symptoms of ciguatera tend to be far more acute and prolonged), scombroid is tasteless and odorless, and there’s really no tried and true method of testing for the toxin. Scombroid poisoning is nowhere near as debilitating or threatening as ciguatera, which is one of the single-most dreaded seafood poisonings, which can either make one feel ill for a couple of days or deteriorate them in the slowest, most excruciating combination of the above symptoms for months, perhaps years. Some have even attributed ciguatera poisoning to death, but the toxin and its effects are still such a mystery to medicine that it hasn’t been confirmed.
All horrors aside, it’s still perfectly safe to eat these fish, but take the two minutes and not only will you feel more at ease, your fish will taste better. If a fish is very carefully handled and kept on ice or in a freezer from the moment it’s caught, the bacteria should not develop, but it’s well worth taking this quick, precautionary measure:
Firstly, you should do this with all fish, even those that you’ve purchased from your local fishmonger (if they haven’t done it for you already). You can remove the blood line from most fish by cutting a triangular-shaped wedge apexing somewhere in the middle of each fillet. It runs along the lateral lines of the fish, on either side of the spine, and although the depth and size of is different in every fish (see the youtube video below for striped bass), it usually doesn’t require too deep of a cut. Make slow cuts to find out where it ends to ensure that you don’t remove any of the good flesh. Larger fish like tuna, however, tend to have very deep blood lines and you’ll find yourself removing several pounds from the fillets (or loins) of larger fish, but don’t feel bad, it could put you on the can for a few days, and nothing is worth that.
Read more about ciguatera, another, more dangerous toxin found in seafood, here. — OJB
Slaughterhouse Animal Blood Collection and Separation
Blood from slaughterhouse animals can be collected by 2 methods. The first, more primitive method, is open draining where blood from the animal is drained into buckets or trays. This method is more susceptible to contamination and blood collected this way is unlikely to be suitable for food applications. Blood, which is to be used for food applications has to come with a guarantee that it is sourced from veterinary-approved disease-free animals. In alive and healthy animals, blood is “sterile” (Dàvila Ribot 2007 ), in the sense that it can be consumed. However, contamination can occur during the blood collection process. Because of its high nutritional value, blood is particularly susceptible to bacterial growth.
The 2nd method is via a closed draining system, where blood from the slaughterhouse animal is not exposed to air and is drained directly from the body of the animal for example, using a hollow knife connected to vacuum piping. However, this method can be more costly and slows down any slaughtering line speed (Dàvila Ribot 2007 ).
Recoverable blood could constitute up to 7% (carcass weight) of most animals (Wismer-Pedersen 1988 ). With the right collection procedures, this blood component can be used as raw material for products for human consumption as well as for technical products. Rigorous control of the temperature of the raw blood and plasma is necessary in order to ensure an end product that meets the exceptionally stringent requirements associated with food-quality ingredients. Many companies provide specialized equipment and systems for separating blood into high-grade plasma and hemoglobin, as well as specialized equipment for turning blood into feed protein products. Edible proteins must be processed with the utmost care if they are to be sold as a high-value item. Such processing must be configured to ensure gentle treatment that minimizes any shear effects that might rupture the red blood cells and contaminate plasma.
According to the FAOSTAT (2012) website, approximately 304 million cattle, 959 million sheep and goats, and 1374 million pigs were processed worldwide for their meat in 2010. Assuming a recovery of 15 L of blood from each head of cattle and 2 to 3 L per pig (Fallows and Verner Wheelock 1982 ), this would amount to huge volumes of blood (for example, cattle—4.56 billion L of blood), which represents a substantial resource and an interesting future opportunity for development. Blood from slaughterhouse animals is a better source when compared to donor animals in terms of volumes being generated. Utilizing slaughterhouse blood in novel ways, such as the production of bioactive peptides (Figure 1), may help in reducing blood discharge and pollution of the environment.
The Meat Lover's Guide to Heme, the Protein That Makes Everyone Crave Blood
Serving up a bloody veggie burger is the trick to convincing carnivores.
Umami boosters be damned — there’s no replacing the metallic richness of a medium-rare steak.
Which is reason for concern, because our meat-eating days are numbered. Cows take up too much land, eat too much grain, and fart too much methane for our appetite for beef to be sustainable much longer. Will meat lovers be forced to accept miso and marmite as umami substitutes forever?
The scientists at Impossible Foods, who are out to create the world’s most convincing veggie burger, think they’ve figured out the secret to replicating the flavor of meat. It comes down to one question: What’s meat got that vegetables don’t? In a word: Blood. And in blood lies a protein called heme, the molecule that could revolutionize the fake-meat industry.
Heme makes up part of the molecule hemoglobin, which turns blood red and carries oxygen around the body. It’s characterized by its ability to carry iron, so on its own, the molecule pretty much tastes like spare change.
The fact that heme isn’t just found in animal blood is what piqued Impossible Foods’ interest. It’s found in virtually all living things, including bacteria and plants. Lance Ignon, a representative for the company, told Inverse that they source their heme from the nitrogen-fixing root nodules of legumes, where it’s a component of the oxygen-carrying protein “leghemoglobin” — kind of like hemoglobin, for beans. This is what gives the company’s veggie burgers their “unmistakable meaty flavor.”
Crafting a truly convincing burger is, of course, more complicated than simply dousing plant fibers with heme, but the molecule does seem to act as the magic catalyst that brings all of the burger’s other flavors together.
“It’s the combination of the right proteins, amino acids, sugars, and fats that come together to create the distinctive flavor of meat,” Ignon says. “But heme is the catalyst for the explosion of chemical reactions that take place when meat is cooked, transforming the simple nutrients found in the raw meat into the unmistakable flavor and aroma of cooking meat.”
Will heme be the fake meat game changer the world is waiting for? By the looks of it, it bloody well could.
High-Fat Meal May Raise Risk Of Blood Clotting -- Increasing Heart Attack And Stroke Risk
DALLAS, Nov. 25 -- A high-fat meal can spark a dramatic rise in a blood coagulation factor, which may increase the risk of death from heart disease and stroke, researchers report in this month's Arteriosclerosis, Thrombosis and Vascular Biology, a journal of the American Heart Association.
A diet high in saturated fats -- derived mainly from meat and dairy products -- can lead to high cholesterol levels in the blood, which can contribute to fatty buildup, called plaque, in the body's blood vessels. The obstructions can block blood flow and trigger a heart attack or stroke.
The new study indicates that fat from the diet -- even the so-called good "mono" fats -- also may increase heart attack and stroke risk by increasing the activity of Factor VII, a blood clotter, says the report's primary author, Lone Frost Larsen. She is a doctorate student at the research department of human nutrition and centre for advanced food studies, Royal Veterinary and Agricultural University, Frederiksberg, Denmark.
"The consumption of a high-fat meal might contribute to acute clot formation. This, in turn, may cause a heart attack by blocking an artery," says Larsen.
The study involved feeding 18 healthy young men five different fat meals. The young men, studied over a period of nine months, were given six different meal tests, each at least three weeks a part. During each test, the men fasted overnight, then were given one test meal enriched with either rapeseed oil, olive oil, sunflower oil, palm oil or butter in the morning and a low-fat meal consisting of rice, bananas and raisins in mid-morning. The high-fat meals were 42 percent fat mixed with rice, beef, onion, red pepper and corn. Non-fasting blood samples were collected eight times during the day.
All five different high-fat test meals caused significant increases in Factor VII. Plasma FVIIc, the nonactive coagulation factor, rose 7 percent after the high-fat meal. FVIIa, the active factor causing coagulation, was 60 percent higher after consumption of the high-fat meal when compared to blood levels of the men after eating a low-fat meal.
Plasma FVIIa increased from 48.4 units per liter (U/L) to 81.4 U/L after the high-fat meal and FVIIc increased from a mean fasting value of .81 international units (IU) to .84 IU after the high-fat meal but decreased to .72 IU among individuals following consuming the low-fat meal.
"These changes indicate an immediate prothrombotic effect of the high-fat meals," says Larsen.
Normally when Factor VII is activated, there is an increase in fibrin, the main component of a blood clot, explains Larsen. "It starts a cascade and eventually a clot is formed. This could later block a vessel and cause heart attack (or stroke)."
The researchers are unsure how fat promotes the sudden activation of the coagulation factors in the blood. Previous studies suggested that a relationship exists between Factor VII and an immediate rise in triglycercides after consumption of a high-fat meal. However, the Denmark team found no such association.
The Denmark study also found no difference in the type of fat eaten by the men during the study. It was assumed that olive oil and rapeseed oil would not produce the same effects as the other fats. Both oils are monounsaturated fatty acids (MUFA) and have been considered more heart healthy than saturated fats.
It was thought that MUFA's might not produce high levels of the coagulation factors because the incidence of heart disease is low in the Mediterranean populations where olive oil is the primary dietary fat, Larsen says. "The people of the Mediterranean have lower rates of heart disease. But our study showed no differences among the fats."
The results, however, showed that fats rich in MUFA do not differ from fats rich in polyunsaturated or saturated fatty acids with regard to the acute effects on the coagulation factors. This may be because the study was done on Danish men who regularly eat diets high in saturated fat. "It may be that we need to see what happens in individuals who eat different dietary fats for a longer period to time," she says.
Since the study was undertaken in healthy young men, another element that remains unknown is whether a more dramatic response would be seen in individuals who already have heart disease. "People with heart disease already have higher levels of Factor VII," she says. "When they have a fatty meal, Factor VII may rise even higher than in the young healthy men, which might put them at even higher risk."
Further study is needed to evaluate why high-fat meals lead to Factor VII activation as well as the long-term effects of different edible fats.
"The important finding is there is an increase in Factor VII after the consumption of high-fat meals," she says. "There is no difference in the type of fat you eat. Individuals should eat diets low in fats with lots of vegetables and fruits."
Co-authors are: Peter Marckmann, M.D. and D.Sc., associate professor at the department of human nutrition and centre for advanced food studies Else-Marie Bladbjerg, Ph.D., research fellow, South Jutland University Center and Jorgen Jespersen, M.D. and D.Sc., professor at South Jutland, Esbjerg, Denmark.
Media advisory: Larsen can be reached at 011 45-352-82506 or faxed at 011 45-352-82469. (Please do not publish telephone numbers.)
Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.
Animal Products Are Linked to Heart Disease
Heart disease is the number one health problem in the United States today, and according to the American Heart Association, it is the single leading cause of death. Most heart disease is diet-related—caused by diets high in animal products.
Meat, eggs, and dairy products are high in cholesterol and saturated fat. (No plant food in the world contains any cholesterol.) As these fatty substances build up inside the walls of arteries as “plaque,” blood flow to all areas of the body is impeded. This artery damage is called “atherosclerosis.” When too little blood reaches various regions of the body, normal bodily functions are impaired, setting people up for a number of diseases, most notably heart disease.
Here’s the good news: Now that we know what heightens the risk of heart attacks, we can take steps to prevent them. Studies have shown that a healthy vegan diet—rich in whole grains, fruits, and vegetables—can stop and even reverse heart disease. People following a plant-based diet have 2.5 times fewer cardiac events, including heart attacks, strokes, bypass surgery, and angioplasty.
Dr. Caldwell Esselstyn, one of the world’s most respected nutrition experts, has been able to make patients who were suffering from clogged arteries virtually “heart-attack proof” by putting them on healthy vegetarian diets and getting their cholesterol levels down below 150. The average vegan cholesterol level is about 146, while the average vegetarian cholesterol level is 177. And the average meat-eater’s cholesterol level is 194. Another nutritionist, Dr. Charles Attwood, points out just how strange it is that more is not done in light of this information: If people were being run down by trucks at the same rate that they’re dying from heart attacks induced by diets high in meat, eggs, and dairy products, drastic steps would be taken.
William Castelli, M.D., director of the Framingham Heart Study, the longest-running clinical study in medical history, says of the heart disease epidemic, “If Americans adopted a vegetarian diet, the whole thing would disappear.” Castelli told PBS that Americans have been “brainwashed to eat meat.”
A major study published in February 2005 reconfirmed the link between animal products and heart problems. The study, which was published in the American Journal of Epidemiology, concluded that among the 29,000 participants, those who ate the most meat were also at the greatest risk for heart disease. The researchers also reported that a high intake of protein from vegetable sources such as tofu, nuts, and beans lowers our risk of heart disease by 30 percent. Dr. Linda E. Kelemen, the scientist who headed the study, told reporters, “Not all proteins are equal”—while vegetable protein can help keep our hearts healthy, eating animal protein can put us in an early grave.
A comparison of blood loss during the Halal slaughter of lambs following Traditional Religious Slaughter without stunning, Electric Head-Only Stunning and Post-Cut Electric Head-Only Stunning
Blood lost at exsanguination during the Halal slaughter of lambs was compared between the slaughter methods of Traditional Religious Slaughter without stunning (TRS), Electric Head-Only Stunning (EHOS) and Post-Cut Electric Head-Only Stunning (PCEHOS). Two protocols were examined, Experimental (80 lambs) and Commercial (360 lambs), assessing varying periods of animal orientation during the 4 min bleeding process (upright orientation before vertical hanging). Live-weight, blood weight (Experimental only), carcass weights and by-product weights were recorded. The Experimental protocol highlighted an increase in blood loss at 60 s in EHOS and PCEHOS compared to TRS (P < 0.001) but by 90 s there was no significant difference. A post-slaughter change in animal orientation from an upright to a vertical hanging position aided the amount of blood loss. The bleeding of lambs is largely completed by 2 min. There were no significant differences (P > 0.05) in final blood loss between treatments. This research was undertaken to inform discussion on the merits of different slaughter methods compatible with Halal requirements.
How Did Humans React?
To see how humans would react to E2D, Lundström and Arshamian rounded up 40 male and female college students. When E2D was pumped through tubes into the students' nostrils, they tended to move backward by a fraction of a millimeter, which the researchers say is a common sign of aversion. They also secreted more sweat than when exposed to the control.
Notably, however, when asked to rate the smell as pleasant, unpleasant, or neutral, students largely rated it as neutral.
Arshamian points out that exposure to E2D doesn't necessarily indicate an aversion to blood.
"One important factor is that learning is really important in olfaction," he said.
The study authors are quick to point out that more research needs to be done before they can say for sure that an aversion to E2D is more innate or subconsciously learned over time.
Lundström suspects the response is more innate. He theorized that the humans' prey-like response stemmed from an early human ancestor that evolved from eating insects and vegetables to one that became what he called an "opportunistic predator."
"Now, we have become a top predator, but naturally we're not top predator," he said.
In a study published in the journal Chemical Senses, Herz found that people are most sensitive to smells in the early and mid-evening. This adaptation could help warn people of the presence of predators when visibility begins to diminish.
In the next iteration of their experiment, Lundström hopes to test E2D on human participants separated by profession and age. He theorizes that people who regularly come in contact with blood, such as surgeons or hunters, may have different responses from those who rarely encounter it. Similarly, he hopes to see if response to E2D changes with age and other life experiences.