Esther Trepal, RD, MS, CDN is our qualified dietician ready to answer the most pressing questions from our readers at the CFYL blog. This one is about the health concerns possibly related to eating red meat.
For decades in cancer research, scientists have studied the link between red meat consumption and cancer. Study results have been mixed, but some convincing explanations of why red meat may contribute to this disease are emerging.
So, you’re probably thinking: Here’s something else I need to cross off my grocery list. But take heart: If red meat is something you or your family just don’t want to, or can’t, part with, there are ways to minimize the risks associated with eating red meat. And it’s easier than you think.
What We Know
Early on in the battle against cancer, scientists noticed that some countries had much lower cancer rates than others. Large population studies compared the diets of people in these countries, and red meat was one food item that stood out as a possible factor. With hundreds of studies conducted over the past decades, there now is convincing evidence that links red meat to the incidence of colorectal cancer. To a lesser degree, red meat is also implicated in cancers of the esophagus, lung, pancreas and endometrium. You can add stomach cancer to this list for grilled or barbecued meats. One large, well-respected study, The Nurses Health Study, showed a link between red meat consumption and premenopausal breast cancer. There is also some evidence for red meat, processed meat and/or grilled meat as promoting aggressive forms of prostate cancer, as well as liver cancer and postmenopausal breast cancer.
Note that “red meat” includes not only beef, but also veal, pork and lamb. And it’s not just fresh meat. Processed meats, such as ham, hot dogs, bacon and all types of cold cuts, are included in this list. Processed meats add an additional risk factor – nitrites.
Red Meat Chemistry 101
There’s a lot of biochemistry involved in the link between red meat and cancer, but here’s a simple explanation. Red meat is a good source of both protein and heme iron, which gives it its red color. In the intestinal tract, the protein mixes with nitrates and nitrites found in processed meats, some vegetables and even water. During digestion, all this is transformed by heme iron, along with certain naturally occurring bacteria in the gut, to form N-nitroso compounds. These are carcinogenic. Note that meat with less heme iron, such as poultry and fish, does not produce the same effect, even though the protein level is comparable.
Red meat, as a source of fat (especially saturated fat), is another possible avenue to carcinogenesis. High intakes of saturated fat are associated with both postmenopausal breast cancer and liver cancer. In addition, high intakes of all types of fat may increase risk of both lung and breast cancer (postmenopausal) as well as colorectal cancer. Finally, eating high-fat foods can lead to overweight and obesity, which are also cancer promoting.
Tip the Balance in Your Favor
Not everyone is convinced that red meat does in fact promote cancer. However, there is a significant amount of research out there that suggests using caution when adding red meats to your diet, especially for cancer survivors and others at high risk for the disease.
For those who are not able to avoid red meat in their diets, or who don’t want to give it up altogether, here are some tips to tip the balance in your favor:
1. Choose lean cuts of meat. Or try red meat from animals that are grass-fed or even wild, such as bison. They will have less overall fat, no hormones or additives, and less of the more harmful saturated fat.
2. Keep portion sizes small, to 3 ounces or less of cooked meat. This is roughly the size of a pack of cards. Don’t eat red meat more than 6 days per week, bearing in mind this isn’t just steak we’re talking about, but pork, sausage, bacon, ham, veal, and lamb too.
3. How you cook meat makes a big difference. High temperatures create carcinogens called heterocyclic amines (HCAs). So, it is best to avoid well-done, crisp surfaces. Use less-heat-intensive cooking methods, such as stir fries, stewing, braising, baking or roasting. Reduce the saturated fat content of slow-cooked braised meats and stews by skimming the fat off the top of the pan before serving.
4. Grilling meat produces another carcinogen, polycyclic aromatic hydrocarbons (PAHs). As the fat from the meat hits the fire, it creates a toxic smoke that rises up and infuses the meat on the grill. Shorten grill times by either marinating the meat beforehand, or partially roasting it. Once it’s on the grill, flip it often. Always avoid charring meat.
5. When eating red meat, serve yourself a small portion and make up your plate with large sides of a variety of fruits and vegetables. When cooking it, up the quantity of fruits and vegetables in stir fries, soups and stews. These cancer-fighting foods can counteract some of the cancer-promoting features of red meat.
6. Support the overall environment within your body daily by eating large amount of fruits, vegetables, legumes and whole grains.