Marinade Does More than Enhance Taste

Marinating meat before tossing it on the grill may do more than just add flavor. Researchers have discovered that marinades rich in spices may help reduce cancer-causing compounds found in steak.

When muscle meat is cooked at high temperatures, potential cancer-causing compounds called heterocyclic amines (HCAs) may form. Some studies have linked HCAs to stomach, colorectal, pancreatic and breast cancers in humans. Temperature is the main factor involved in HCA formation. Barbecuing produces the most HCAs, followed by pan-frying and broiling. Baking, poaching, stir-frying and stewing produce the least HCAs.

Scientists from Kansas State University found that antioxidant-rich spice and herb marinades may decrease HCA formation in steak by up to 88 percent.

The researchers tested the effects of three different pre-packaged marinade mixes in typical home-cooking conditions. Fresh eye of round beef steaks were immersed in Caribbean, Southwest or herb marinade mixes for one hour. All of the marinades contained at least two spices from the mint family, which are rich in the antioxidants.

The steaks were about 3.3 ounces each and one-fifth of an inch thick. These steaks, as well as non-marinated steaks and steaks in non-spice marinades, were then cooked on an electric skillet at 400 degrees Fahrenheit for five minutes per side.

After cooking, the researchers compared the levels of HCAs in all steaks and found that steaks marinated in the Caribbean blend had an 88 percent decrease in HCA levels. The herb blend reduced HCAs by 72 percent, and the Southwest blend reduced levels by 57 percent.

Comments

[Mark]

This is very interesting information. I wonder what brands they used in the study. A study in the future would be useful if they could pinpoint the exact herbs that have the greatest reduction effect of HCAs, so you can better prepare your own marinades.

[Penny T.]

Now researchers need to tell use whether these benefits negate or balance out the dangers of eating charred food from the grill, which has been mentioned in the press as another way we increase our risk of cancer. I remember an NPR story that also mentioned fruits, such as cherries and blueberries, added to your meat are good for cutting down on the formation of these pesky HCAs. All of this means nothing, I suppose, because if you undercook the meat, you leave harmful bacteria like E coli roaming around.

[Bethaney]

This meat must have been really charred. For such thin pieces of meat, it seems like they cooked it for an awful long time. Are HCAs more likely to form if you use a charcoal grill instead of a gas grill? I always thought that the charcoal was what lead to HCAs, but I guess it really has more to do with the temperature.

[HC]

This is bad news for those who like their food well done - with those pretty black grill marks. I agree with Bethaney and wonder if this would hold true for food cooked on a gas or charcoal grill? It seems that it’s the temperature of the meat that makes the difference, and gas grills are easier to control the temperature than charcoal. Ways to minimize the risk of HCAs include using marinade, using thinner cuts of meat, and cooking on a lower temperature. Hopefully, these are practices that we all use when we grill!

[Jason]

Now with this news of HCAs, I see that there is a lot more to think about when cooking meat. People are usually worried that meat is undercooked and getting sick from that. I had never even heard of HCAs or their link to cancer before this!

[Minney]

I think this is great news! My family is originally from India and we usually make our own spicy marinades and use it on all meats before cooking. It's good to know that marinating could make food not only tastier but healthier too!

[jeremy]

Four factors influence HCA formation: type of food, cooking method, temperature and time. HCAs form when amino acids and creatine (a chemical found in muscles) react at high cooking temperatures. There have been 17 different HCAs identified from the cooking of muscle meats that may be a human cancer risk. Heterocyclic compounds are organic compounds that contain a ring structure containing atoms in addition to carbon, such as sulfur, oxygen or nitrogen, as part of the ring. They may be either simple aromatic rings or non-aromatic rings.

[Eval]

Actually this is old news. The knowledge that marinating decreases HCAs was discovered about 10 years ago. In addition to marinating, microwaving meats prior to grilling can also decrease the amount of HCAs in the final product. Whether microwaving actually decreases the level of HCAs or pre-cooks the meat, thereby decreasing the amount of time the meat spends on the grill, I don’t know. Either way, the combination of marinating and microwaving may have additive effects…another potential study question!

[Mario]

The source of the HCA is through the chemical reaction of amino acids and creatine. Creatine is naturally found in muscle tissue. Creatine assists in providing energy to muscle and nerve cells. This chemical reaction happens at really high temperatures, like when you use BBQ grills. It results in the formation of these HCA compounds. Other sources of protein that are not derived from muscle tissue, such as soy and eggs, contain very little, if any, HCA naturally.

There is also another harmful carcinogen found in meats that are cooked at high temperatures. PAHs (polycyclic aromatic hydrocarbons) are formed when the fats of meats are dripped onto the heat source, such as the charcoal. The fat then heats up and forms PAH, which then goes back up with the smoke towards the food and coats the food.

Along with marinating the meats, there are also other techniques to help minimize these carcinogens. Putting tin foil and poking small holes through it and placing it on top of the grill will help divert some of the PAH-containing smoke to reduce exposure. Elevating the grill above the charcoal by placing bricks on the side of the grill can also help. Precooking certain meats before putting them on the grill also helps reduce cooking time on the grill, which reduces PAH smoke exposure and decreases the chance of charring the meat since it is on the grill for a shorter amount of time, so fewer HCAs will form.

[Batool]

Here is some more information I found about heterocyclic aromatic amines: They are formed in protein and amino acid-rich foods at temperatures above 150 degrees C. Ten heterocyclic aromatic amines have been shown to have carcinogenic potential out of more than 20 that have been identified. Now I need to research the Caribbean blend marinade. Anyone know if it’s any good?

[Sean]

This article is pretty reminiscent of the one about the dangers of burning incense. There are many dangers involved when products are burned and consumed. At least there can be some risk reduction when the burned parts of meats are removed before eaten. At least with the marinating process, the meat will be much more flavorful!

[ali]

While the results of this study are not new information, it confirms the fact that marinades can decrease the HCAs when grilling. Adding marinades to meat only enhances the flavor. The protection may be linked to antioxidants found in some of the spices. If one eats these foods in moderation anyway, shouldn’t that decrease the chance of developing cancers from the HCAs? Is there a documented link to a certain type of cancer and grilled foods?

[wayne]

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. 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 and where a larger amount of meat is consumed. I find this quite ironic! We might be at less risk for cancer ingesting fast-foods, but at an exponentially greater risk for cardiovascular disease and dyslipidemia.

[Tina W.]

In addition to the cancer-causing potential of grilling outdoors, one must not forget that most kinds of charcoals bought at a typical store do not burn cleanly. There are additives inside the charcoal briquettes, such as coal dust, borax, limestone, sodium nitrate and starch, which when burned on a grill get into the atmosphere, polluting it slowly. Also, the use of charcoal should be in well-ventilated areas only, since charcoal burns and results in the production of carbon monoxide.

[SUMA]

This article captures one’s attention! The rising incidence of obesity and society’s current focus on healthy lifestyles – exercise, eating organic foods, eliminating processed foods etc., often overlooks one important factor - food preparation. This is an eye opener! Why go to all of the trouble (and expense) of purchasing healthy foods only to destroy all of its benefits with cooking?

The hectic, stress-filled lives lived by many of us demand simplicity. What could be simpler than marinating prior to cooking? Also, marinades can tenderize and boost the flavor of meat while keeping it moist during grilling.

The Caribbean marinade contained thyme, red and black pepper, allspice, rosemary and chives. The Southwest marinade was made with paprika, red pepper, oregano, black pepper, garlic and onion. The herb marinade was prepared with oregano, basil, onion, jalapeno, parsley, and red pepper. Rosemary has also been found to block the HCAs before they form. All of these ingredients are readily available in grocery stores. What could be simpler?

Other tips to consider - marinate meat for at least one hour and flip the meat every minute while cooking. To avoid a different class of cancer-causing compounds called polycyclic aromatic hydrocarbons (PAHs), grill leaner meat cuts that will drip less and cause fewer flare-ups and smoke. PAHs form in the smoke and are deposited on the outside of the meat.

[Van]

I heard that cooking meat in the microwave is not healthy, but I do not know the science behind that. If cooking meat in the microwave reduces the time that it is on the grill and therefore, the number of HCAs formed, then that is great! Anyone know more about the dos and don'ts of microwaving meats?

[ohmi]

One of my questions with the study is what causes the decrease in HCA formation? If it were just the marinade itself being on the meat, then the decrease in levels would be similar among all marinades (Caribbean, herb and southwest). Does this study indicate that we should all be cooking with a Caribbean-blend marinade? I don’t think so. But it brings up an interesting point about why each marinade had a different decrease in HCA formation.

[Eugene]

Meats that are partially cooked in the microwave oven before cooking by other methods have lower levels of HCAs. Evidence suggests that microwaving meat before cooking helps decrease HCA formation by removing the precursors. Microwaving meats for two minutes before cooking decreased HCA content by 90 percent. Also, if you pour off the liquid that forms during microwaving, it will further reduce HCA formation.

[Aaron]

I was under the impression that all burned food off the grill is cancer causing. However, this is not the case. Burned vegetables actually are not cancerous, even though they may be severely charred. It is really just the HCAs and PAH that causes the cancer.

[R.Chow]

The mechanism in which the microwave removes HCA is by removing its precursors. A study shows that if meat is heated with a microwave for 1-2 minutes, its mutagenicity decreased by 50 fold. After the 1-2 minutes of heating, the water in the meat is separated from the meat itself, drawing out the water-soluble HCA precursors.

[Sunny]

I wonder if the same outcomes are true when using a brine or rub on meat, or if it must be a marinade? Marinades are defined as flavor-infusing liquids, often containing herbs, condiments, spices, oils, and some acid (lemon juice, wine, vinegar, or dairy). A brine is a salty solution in which meats (normally lean meats) soak. A rub is a seasoning mixture that is applied to meats before grilling for smoky or spicy flavors.

[JB]

Here are a few tips for microwaving meat and poultry: de-bone large pieces of meat. Bone can shield the meat around it from thorough cooking. Cook large pieces of meat on medium power (50 percent) for longer times. This allows heat to conduct deeper into meat without overcooking outer areas. Turn large food items upside down so foods cook more evenly and safely. Do not microwave whole, stuffed poultry. Cooking meat is so rapid that the stuffing inside might not reach a sufficient temperature to be safe. Never partially cook food. When microwaving food partly done to finish cooking on the grill or in a conventional oven, transfer the microwaved food to another heat source immediately. Use a meat thermometer or the oven’s temperature probe. This is important to verify the food has reached a safe temperature after cooking. Check in several places to be sure red meat is 160 °F and poultry, 165 °F. Ovens vary in power and efficiency. Allow standing time, which completes the cooking, before checking the internal temperature with a food thermometer.

[Hank]

This article suggests that barbecuing produces the most HCAs. Does anyone know if there is a difference in grilling methods? Was there a difference in fuels used for the fire, like charcoal, wood or propane? It also mentions that the researchers used beef, so I wonder if there are benefits to marinating chicken, pork or seafood before grilling.

[andrew]

Since all of the marinades contained at least two spices from the mint family, which are rich in antioxidants, this may be the central ingredient that is decreasing the amount of HCA formation. Antioxidants are substances that may protect cells from the damage caused by unstable molecules known as free radicals. Free radical damage may lead to cancer. Antioxidants interact with and stabilize free radicals and may prevent some of the damage that free radicals otherwise might cause. Examples of antioxidants include beta-carotene; lycopene; vitamins C, E and A and other substances.

[Joe D.]

I am surprised and sad that the charred parts of the meat are the parts that contain the most HCAs. I love the grill marks on my hot dogs and burgers when we have a cookout. Microwaving the food beforehand? That will probably change the taste of the food. There is a reason why I want to grill my own burgers - so they don’t taste microwaved like McDonald's burgers.

[Tamara]

Scientists aren't sure exactly how marinades act to reduce the formation of carcinogens. There is evidence, however, that marinades may act as a barrier or that their protective powers may lie in their ingredients. Acidic ingredients, like vinegar or citrus juices; herbs; spices and oils all seem to contribute to the prevention of HCA formation.

About one-half cup of marinade is needed for every pound of food, although large pieces may need more to adequately cover the food's surface. Total immersion is not necessary, but the food should be turned occasionally, so that all surfaces will be in contact with the marinade long enough to benefit. Use a non-metal container or a sturdy, resealable plastic bag to hold the marinating foods.

[charlotte]

Using antioxidant-rich herb marinades is one of several ways to decrease HCA formation when grilling steak. I’ve also read that certain cherries and olive oil have been shown to decrease HCA formation as well. The cherries may not work so well for steaks, but if grilling burgers, they could be mixed into the meat to create a new flavor, as well as a healthier burger. Rosemary extract added to the surface before grilling is another way to decrease HCA formation and will not change the flavor of the meat greatly for those who do not like spiced marinades.

[Emma]

This is a great article. I'd like to learn more about HCA formation. Usually I make spicy marinades before cooking, but I didn’t know that marinating could make food not only tastier, but also healthier. Really, it’s such a good article.

[Wendy]

It makes sense that antioxidant-rich spice and herb marinades would decrease HCA formation. Free radicals are formed when exposing most carbon-containing material to high heat. Antioxidants quell the formation of free radicals, which are the cause of many damaging secondary reactions.

Although tight control was performed on thickness and weight of steaks, there was no mention made on the amount, nor the level of antioxidants in any of the marinades. The report did identify the spices as “those found in the mint family.” Mints are typically known for their anti-inflammatory effects.

[Becca]

To me, grilling meat has always been delicious, but as a dietitian, it has been in the back of my mind that I could be ingesting cancer-causing compounds. If marinating with herbs can help decrease the risk of these cancer-forming compounds, then that is amazing and delicious!

[liz]

I would rather use antioxidant-rich spices and herbs to reduce the formation of heterocyclic amines than use a microwave. Unlike a microwave oven, the marinade is also adding flavor and tenderizing the meat. On the other hand, microwaving food is known to alter the structure and change the nutrients in food. Microwaving meat leads to the formation of nitrosodienthanolamine, which is a carcinogen.

[Sam]

Eugene, thanks for explaining a little bit about microwaving meats. I was not entirely sure what microwaving could do due to decrease the HCA content in meat, but it is good to know that it can decrease the HCA content by 90 percent! Also, aren't there dangers to cooking meat in the microwave for too long?

[Jarvis]

The abstract reads that the marinade instructions say to mix the spices with oil, water and vinegar. There should have been a control to include stakes marinated with oil, water and vinegar alone to determine what the effects of those ingredients are in reducing HCA production.

[chad]

So consumption of how much grilled meat will pose an increased cancer risk? What are some alternatives to cooking the meat that will give the same satisfaction? Here is some information I found to help clarify these questions (http://cancer.about.com/od/foodguide/a/grillingmeat.htm): Experts recommend that foods be cooked at lower temperatures, even if it means cooking longer. The goal is to prevent charring the meat. You can do this on a charcoal grill by allowing the flames to go down after lighting. On a gas grill, try raising the grill rack, away from the heat. Using skewers is also an excellent way to limit the amount of grilled meat consumed during a meal. Small pieces of meat, combined with fresh fruits and vegetables on the grill make for an attractive and delicious meal. Keep in mind that just like everything in life, moderation is key. There is only an increased risk of cancer when excessive amounts cooked at high temperatures are consumed. You still can enjoy grilled meats, but just do so in moderation and when cooked at low temperatures.

[Harry]

Decreasing cancer potential by removing up to 88 percent of the HCA sounds astounding! I will definitely remember to leave my steaks in the marinade a bit longer now. Tastier and healthier!

[Anna]

I would be interested to know more about the spices in the marinades that reduced the HCAs. I always thought that it was the smoke from the barbecuing that caused the problem, but it seems to be more related to the heat. I think that for such a small-sized steak it was cooked too much. What happens to meat that is cooked to a medium-done stage instead of a super-well-done stage? How does this affect the HCAs?

[prime]

Jarvis brings up a good point. I am interested to learn about how much HCA would have been found on a control piece of meat that was not covered with marinade at all. The scientists measured the three pieces of meat and compared them against which control? How did they know the marinade reduced HCA levels?

[JL]

Anna,

The researchers did use a control. They compared the marinaded steaks to those that were not marinaded. "These steaks, as well as non-marinated steaks and steaks in non-spice marinades, were then cooked on an electric skillet at 400 degrees Fahrenheit for five minutes per side."

[michelle]

I disagree with Chad. I think using skewers in grilling would subject the eater to more HCAs. Since the pieces of meat are smaller, there is more surface area on the outside of the same amount of meat that would get cooked at high temperatures, forming HCAs. Perhaps grilling slowly over a wood fire would form less HCAs; trying different sources of fire could be an area of further research.

[TL]

HCAs are compounds that are formed when amino acids and creatine react at high temperatures, as often occurs in overcooked meat. And since meats contain amino acids (protein), we can see that overcooked meat would produce lots of HCA. According to the study, HCAs are suspected human carcinogens formed in muscle foods during high-temperature grilling or cooking. Now what I would like to know is what kind of herbs/spices the researchers were using in the study to get the results they published.

[think twice]

So if meat cooked at high temperatures form HCAs, then at what temperature should we be cooking our meats? What is the cutoff to avoid eating rare meat versus ingesting HCAs? I am not impressed with marinades decreasing HCA levels. Consumers should caution their use of certain marinades and flavor enhancers. MSG (monosodium glutamate) is a food additive that is commonly used as a flavor enhancer, and it has its adverse health effects. Although MSG was not mentioned in this story, it may decrease HCA levels, but what does it increase?

[PK]

I wonder if marinating even longer would have decreased the amount of HCAs found in the liquid control steaks. Acidic marinades partially cook meats. This could decrease the grill time in a manner similar to the microwave precooking. The idea that spices could decrease the harmful effects of food is not really surprising, as spices were originally used to preserve foods.

[Jeff]

Good question, Bethany. I never knew about HCAs or their link to cancer before reading this. So what is it about the marinade that reduces the HCA levels? Is it the antioxidants in the spices? This study used beef, but are there similar benefits in marinating chicken, pork or seafood prior to grilling?