Meat cancer prevention is at the top of our menu today. This is a follow-up to last week’s post (Bacon Cancer) which discussed the cancer hazards of eating meat. This blog focuses specifically on how we can minimize our risk, while still deriving the enjoyment and nutritional benefits of eating meat.
This blog contains a lot of detail – if you just want the practical advice, skip forward to the Summary section near the end.
Meat Cancer Prevention: Guardian Angels
Last week we labeled the harmful elements in meat as evil spirits trying to do us harm. If there are evil spirits in our food, are there also guardian angels to defeat them?
Most concern about bacon cancer and other meat cancers has been focused on finding the foods, additives and cooking methods that have the least cancer-causing effect. However, research has also uncovered evidence that some foods may help block the bad effects of food carcinogens. What little evidence exists comes from epidemiological studies of people, plus biochemical research on animals.
Here are the potentially protective foods that can help meat cancer prevention:
Fiber derived from eating fruits and vegetables is a “protective factor” for meat cancer prevention. Conversely, people who consume low amounts of fiber seem to have an increased risk of contracting cancer by consuming meat.
Current research shows that allium vegetables, such as garlic and onion, block the formation of cancer-causing nitrosamines. Add onion powder to ground meat, sprinkle garlic powder on meat surfaces, or add these to your marinade.
The chlorophyll from vegetables also appears to counter the risk of meat-caused colon cancer.
The mineral calcium seems to suppress cancer caused by both red meat and processed meat. You must consume it at the same time as the meat. Calcium helps precipitate heme within the large intestine so that it does not promote tumor growth by converting to nitrosamines. However, not all forms of calcium are equal. Calcium carbonate suppresses cancer, while calcium phosphate does not.
This website has previously cited health benefits from coffee, alcohol and berries. However, it’s wise to drink in moderation. Too much alcohol may itself cause cancer, or may weaken the body’s ability to fight it.
Meat Cancer Prevention: False Angels
Many other foods have been studied in hopes of finding still more, and more effective, approaches to meat cancer prevention. The following hoped-for saviors are still unproven:
– Antioxidants and olive oil, taken either separately or together, have given inconsistent anti-cancer results in various studies.
– Eating fish or poultry, as noted above, has shown a weak cancer-preventive effect in some studies but not in others.
– Ascorbates (vitamin C) are added during meat processing to reduce the formation of nitrosamines. Therefore, researchers have looked to see whether vitamin C could also block nitrosamine production in the digestive tract. Unfortunately, the chemistry of ascorbic acid is very complex. Moreover, in the presence of fat, vitamin C may actually increase nitrosamine formation. I conclude that we can’t yet be sure whether vitamin C fights cancer or encourages it, when consumed along with meat.
Meat Cancer Prevention: You Must Eat the Good Stuff at the Same Meal!
In the case of fiber and calcium, the cancer-fighting benefit comes from suppressing chemical reactions during digestion. Those reactions would otherwise convert healthy food into cancerous chemicals.
For the most effective meat cancer prevention, it’s important to eat your fruits and vegetables during the same meal. We know that it takes a couple of hours to empty the stomach after eating. Therefore, eating the produce with the meat ensures that the guardian angels will be well mixed with the evil spirits, as both undergo digestion.
When you eat healthy foods to fight Alzheimers, heart disease and other maladies, it doesn’t matter when you eat them. Such foods, if they are effective, act only after they are digested and enter the bloodstream. So long as they are absorbed properly into the blood, your body doesn’t care when you consume them.
However, cancer of the digestive system is different: since the bad chemical reactions happen within your body during digestion, you need the good stuff to be present at the same time. A fruit salad at lunch followed by a gigantic steak at dinner will do you no good at all. Instead, you need to put both foods into your body during the same meal.
Meat Cancer Prevention: Exorcising the Evil Spirits
A careful reader will have noted that although meat, especially processed meat, is a strong cause of cancer, the guardian angels to counteract it are relatively weak and ineffective. However, there are steps that anyone can take to attenuate the evil spirits. Consequently our bodies, with the help of the “angel foods,” can gain the benefits of a meat diet while fending off cancer.
Here are some important ways to exorcise those bad actors.
Buy Uncured Meat
You should be suspicious of the word “natural” on a packaged food because there is no legal definition of what “natural” means. However, the concept of “natural” food, meaning food that has undergone minimal processing, is definitely sound.
One way you can ward off digestive cancer is to replace the processed meats in your diet with meats without additional nitrate or nitrite. Try to buy “uncured” meat. Read the label and make sure that it has no added nitrate or nitrite.
Uncured bacon is readily available at grocery stores. If you are diligent, you can also find uncured hot dogs, lunch meat and sausages. Many markets carry the Applegate Farms brand. Trader Joe’s also carries uncured meats under its own label, including full-sized hams. Uncured meats are also for sale online.
“Uncured” Is an Official USDA Label
Note that the label “uncured” on a meat for sale in the United States is a USDA designation meaning that it has not been preserved using added nitrates and nitrites. It does not mean that the meat is raw. If the meat has been preserved by other means, such as with salt and spices, it is safe to eat “as is” unless the package instructions specify that it requires cooking.
Uncured meats are just as tasty and a lot healthier for you. However, they generally have a shorter shelf life. Usually you should eat or freeze them within a week after opening the package.
Nola and I buy uncured bacon and freeze the slices in plastic freezer bags, using parchment paper to separate individual slices. We can easily remove however many slices we need for a recipe. Frozen slices cook just as quickly as non-frozen bacon.
Another tasty yet natural form of processed meat is prosciutto. However, be sure to read the label: you want the ingredients to be pork and salt – nothing more. Traditional prosciutto is preserved by salt and does not require nitrates or nitrites for proper shelf life.
A 2019 Update
Note added August 2019: The October 2019 issue of Consumer Reports includes a special report “Danger at the Deli.” CR discusses the fact that “uncured” meats do not have nitrates and nitrites added to them. However, uncured meats do include some nitrates and nitrites contained in celery and other natural additives.
So, are uncured meats safer? CR sniffs that the net nitrate and nitrite levels “were almost the same for cured and uncured meats.” In fact, that statement does not accurately summarize their data. CR’s data shows that “uncured” means have 40% lower nitrates and 25% lower nitrites compared with “cured” meats.
Therefore, CR’s data shows that “uncured” meats contain the same risky chemicals as “cured” meats, but the amounts of those chemicals are smaller. Smaller, but not zero!
We can agree with CR’s bottom line, which is that the safest approach is to eat only small portions of “deli meat” of either kind.
This blog has previously discussed ways to barbecue meat more safely by the use of marinades and smart cooking. A useful research article by Alaejos and Afonso compiles a number of recommendations to reduce carcinogens in cooked meat. I present them here in slightly edited form:
- Choose lean cuts. Apply lower temperatures and shorter cooking times.
- Grill or pan fry only at low temperature (less than 180 Celsius = 350 Fahrenheit).
- Turn food frequently during cooking.
- Avoid direct contact of meat and fish with a naked gas flame or charcoal.
- Do not let meat drippings dry out before making gravy.
- Avoid browning of foods or, at least, remove the crust and charred parts of fried or grilled meat, poultry, and fish.
- Cook meat and fish in aluminum foil to reduce charring.
- Remove the skin from barbecued chicken.
- Rather than grilling, use other cooking techniques: boil or poach fish; stew beef; or microwave either.
- Before grilling, precook meat in an oven or microwave to reduce time on the grill.
- Use marinades that contain little or, preferably, no sugar. If you want a sugared barbecue sauce, add it only after cooking.
- Cook meat and fish together with foods containing phenolic antioxidants such as tomatoes, carrots and other vegetables. Kebabs, anyone?
Choose Lower-Heme Meats
All meat contains blood, and blood contains heme. Heme is valuable since it’s a good source of iron, an essential nutrient. However, if you are not iron-deficient, then it’s a good idea to choose meats with less heme, since heme partly converts to carcinogens during digestion.
Note that if you are concerned about not getting enough iron, there are plenty of non-meat sources of iron:
– Vegetables, notably beans, peas and spinach, are good sources of iron. However, vegetable iron is two times less readily absorbed by the body. Therefore vegetarians are advised to consume twice as much iron from food as non-vegetarians.
– Fish, especially shellfish and sardines, are another non-meat source of iron. Sources often classify the iron in fish as “heme iron.” However, iron from fish is biologically quite different from iron in mammal meats. Fish rely on hemocyanin to transport oxygen to their tissues, which differs from hemoglobin by having copper atoms rather than iron atoms. I can find no literature associating the iron in seafood with an increased risk of cancer. In fact, there are a few studies that show consuming fish as protective against cancer.
Reducing Your Risk
Let’s assume that you are not ready to give up animal meat, but would still like to reduce your risk of disease.
Once you stop buying meats with nitrates added and cook your meat more safely, meat cancer prevention may be simply a matter of eating more low-heme meat and less high-heme meat.
The sources I consulted give differing numbers for the heme content of meat. They are usually within twenty percent of each other, although in a few cases I found values that are a factor of two apart. Absolute accuracy is not possible, because heme content varies. It depends on factors such as the cut of meat, the cooking method and the degree of doneness.
And Here’s the Data…
In any case, here are my estimated heme values for various common animal meats, in micrograms of heme per gram of meat:
This list offers some surprises. I was startled to see “dark meat” poultry (chicken thigh and duck meat) ranking above bacon. Moreover, pork and veal are amazingly low on the list. It may not be a joke to refer to pork and veal as the “other white meat.” They are lighter in color because they contain less heme. As a result, they are almost as noncarcinogenic as the blandest, whitest breast of chicken.
Although the most lurid news headlines have featured cancer from bacon, bacon ranks pretty low on this list. Provided, of course, that it is uncured bacon and that you don’t overcook it. Suppose that an average serving is two ounces (two slices) of bacon and four ounces of chicken. Then a serving of bacon contains about the same heme as a serving of chicken breast. Bacon cancer, get thee behind me!
In any case, here are my takeaways from this list:
– Liver and other organ meats should be only a rare treat.
– Try to eat more fish, pork and chicken (and veal, if your personal preferences allow it). And
– Eat fewer hamburgers and steaks.
Summary – Meat Cancer Prevention
Here are the key points from the discussion above. You can help prevent cancer from eating meat by taking some or all of the following steps:
– At the same meal that you eat meat, consume some “guardian angels”: fruit or vegetables, and calcium (from milk or supplements).
– If you buy processed meat (hot dogs, bacon, ham, sausage, lunchmeat), buy the type labeled “uncured.” And check the label to make sure that it contains no added nitrates or nitrites.
– Cook safely by using nonsugary marinades and cooking at lower temperatures. If you want to grill or barbecue, shorten the time on the fire by pre-cooking the meat in oven or microwave.
– Eat more fish, chicken, pork and veal. Eat fewer hamburgers and steaks.
As mentioned at the beginning of the previous blog on Bacon Cancer, cancer is exceedingly complicated. There is a great deal that we simply do not know about why it occurs and how to prevent it. However, it makes sense to use the limited knowledge that scientists have amassed. Choose and buy healthy food, and cook it safely.
If you keep meat cancer prevention in mind at the grocery store and in restaurants, you can make healthier choices while still enjoying the pleasure of good food.
– Developing a Heme Iron Database for Meats According to Meat Type, Cooking Method and Doneness Level.
– Dietary Sources of Iron.
– Iron Content of Duck.
– Iron, table of values per serving.
– Meat that Contains High Iron.
– Nutrition Comparison of Veal & Pork.
– Selected Food Sources of Iron.
– Top 10 Foods Highest in Iron.