MEAT IN THE HOT SEAT!!!

1. Sources: Diet & Nutrition, Fit for Life, Star Paper, 8 July 2007.
2. Sources: National Cancer Institute

Recent research shows that cooking meat at high temperatures or overcooking them over long periods of time produces cancer causing chemicals.

When we eat meat or fish, we are eating the muscle tissue n some collagen that makes up the connective tissue ( the more the collagen the tougher the meat), and fats as well. By cooking the meat, it turns the tissue pleasently firm n juicy by altering protein inside the muscles so it gets more compact n squezees out the water.

By cooking the meat directly in high temperatures (ranging from 140 to 150 degrees F), the water immediately gushes out n the protein bunches up even faster n pratically causing the tissues to shrivel.What has been tender and juicy is on its way to becoming a shoe leather. Ruining a piece of meat isn't the only thing u need to worry about if u are cooking at temperatures. With heat, the amino acids, building blocks of protein wud react with creatine which is a compound found in the muscle tissues. The reaction would produce heterocyclic amines. They are produce in tiny amounts, measured in billionths of grams. But lab n animal experiments show that these compounds have potent cancer causing properties.

The International Agency for Research on Cancer has classified several of them as possible carcinogens. Carcinogens are substance, radionuclide or radiation that is an agent directly involved in the promotion of cancer or in the facilitation of its propagation. This may be due to ability to damage the genome or to the disruption of cellular metabolic processes. Carcinogens may increase the risk of getting cancer by altering cellular metabolism or damaging DNA directly in cells, which interferes with biological processes, and induces the uncontrolled, malignant division, ultimately leading to the formation of tumors. Usually DNA damage, if too severe to repair, leads to programmed cell death.

Meanwhile, the epidemiological evidence that frequent meat eaters stand a greater chance of getting several forms of cancer, continues to grow. In 2007, studies were published that a link high meat consumption to breast n kidney cancer. Late 200, Harvard researches reported that high intake of red meat (beef, lamb, pork) may be risk factor for oestrogen-sensitive breast cancer among pre-menopausal women.

Another study conducted by researchers from NCI's Division of Cancer Epidemiology and Genetics found a link between individuals with stomach cancer and the consumption of cooked meats. The researchers assessed the diets and cooking habits of 176 people diagnosed with stomach cancer and 503 people without cancer. The researchers found that those who ate their beef medium-well or well-done had more than three times the risk of stomach cancer than those who ate their beef rare or medium-rare. They also found that people who ate beef four or more times a week had more than twice the risk of stomach cancer than those consuming beef less frequently. Additional studies have shown that an increased risk of developing colorectal, pancreatic, and breast cancer is associated with high intakes of well-done, fried, or barbequed meats.

Four factors influence HCA formation: type of food, cooking method, temperature, and time. Any burned protein may contain heterocyclic amines, but the amounts in eggs n tofu are small compared to those in meat derived from muscles tissue bcoz muscle tissue is well supplied with creatine. Although many epidemiological fingers point at red meat as the prime suspect but when we consider about heterocyclic amines, fish n chickens area also in the suspects list as well. Eventhough they are healthier choices than red meat but that's principally only bcoz of the amount n type of fat they contain but the amount of heterocyclic amines arent considered. Basically speaking chicken, fish, beef n pork, they are all meat products n all of them have these cancer properties when overcooked.

The most important to the formation of heterocyclic amines (HCA) is temperature. Frying, broiling, and barbecuing produce the largest amounts of HCAs because the meats are cooked at very high temperatures. One study conducted by researchers showed a threefold increase in the content of HCAs when the cooking temperature was increased from 200° to 250°C (392° to 482°F). And the HCAs are concentrated in the outer few millimeters of a piece of meat closest to the heat source. Griling (especially by charcoal method) is double trouble bcoz it also exposes meat to the cancer causing chemicals called polycyclic aromatic compounds contained in the smoke wafting from burning charcoal. Oven roasting and baking are done at lower temperatures, so lower levels of HCAs are likely to form, however, gravy made from meat drippings does contain substantial amounts of HCAs. Stewing, boiling, or poaching are done at or below 100°C (212°F) n produce less HCAs.

Time for the meat to be cooked is also a important factor in HCA formation. Recent experiments conducted show that meat fried for 10 mins at about 450 degrees F contains over twice the amount of heterocyclic amines as meat fried at temperature for just 4 mins. Even by cooking the food for long time using lower temperatures (by baking or roasting meat) would also increase the amount of HCAs eventhough the increase isn't as steep as with food cooked at higher temperatures over long periods.


For a safer consumption of meat products, there are some techniques u can follow. Cook the meat at lower temperatures n for shorter periods of time as it would reduce the the amount of HCAs in it. Here are some tips from the National Cancer Institute (NCI) n other sources that make meat a bit safer to eat.

1. Cook the meat in smaller pieces as they chemically u guys know they cook more quickly n cook it in lower temperatures.
2. Make sure leaner meat is choosen. Less fat shud reduce the flames n therefore the smoke that contains the cancer causing agents.
3. Warm up the food b4 cooking it. By warming it up, the time needed for the meat to be cooked would be less. It is suggested that wrapping steaks n chops an putting them in warm water for 30 mins to 60 mins. BUT if u do this, cook the meat immediately bcoz bacteria grow quickly on warm meat.
4. Best tip precook in the microwave. Meats that are partially cooked in the microwave oven before cooking by other methods also have lower levels of HCAs. Studies have shown that microwaving meat prior to cooking helps to decrease mutagens by removing the precursors. Meats that were microwaved for 2 minutes prior to cooking had a 90-percent decrease in HCA content. In addition, if the liquid that forms during microwaving is poured off before further cooking, the final quantity of HCAs is reduced. (Usually if u cook meat it produce drippings. Dont make a gravy out of it as it contains high levels of HCAs. So its best the drippings be removed)
5. Frequent flipping when cooking meat. Frequent flipping means neither side has time to absorp or lose too much heat. So the meat cooks faster n the outer layer ends up less overdone-and presumably with fewer HCAs.

Marinading meat is often suggested as one way to cut down on the formation of HCAs, therefore safer for the meat to be consumed. The thinking is that the marinade will keep the meat moist and its temperature down. In addition, some marinades imbue meat with antioxidants that offset the HCAs. But when marinades haven been put to the test in studies, the results are mixed. For example, in an experiment it is found that marinating chicken decreased one type of HCAs but increased another.

Another study found that while teriyaki n turmeric-garlic sauces decreased HCA in a grilled steak, BBQ sauce increase them. So I think marinading meat isn't a good choice.

And if u guys are soooooooooo lazy to cook at home n u want to eat in a restaurant. Might as well u pick fast food restaurants rather that a non fast food restaurants. One study has evaluated the content of HCAs in fast food restaurants. After evaluating five kinds of meat products from various fast food restaurant chains, the study concluded that there were low levels of HCAs found in fast food meat products due to factors such as cooking temperature and time(which is shorter). The study suggested that greater exposure to HCAs stems from home cooking and cooking in non-fast-food restaurants where food may be cooked to order (takes longer time) and where a larger amount of meat is consumed.