START A PETITION 25,136,189 members: the world's largest community for good

Estrogens in Cooked Meat

We’ve known since 1939 that there were “cancer-producing substances” in roasted meat. Scientists have since identified these compounds as heterocyclic amines, described by the National Cancer Institute as “chemicals formed when muscle meat, including beef, pork, fish, and poultry, is cooked using high-temperature methods, such as pan frying or grilling….”

As I describe in my 2-min. video Carcinogens in Roasted Chicken, studies on rodents have historically downplayed the risk, suggesting 99% of these chemicals can be removed by the liver. Humans, it turns out, are actually 50 times less able to detoxify these carcinogens, however, which may explain why studies done on Long Island and around the world have shown women eating more broiled, grilled, fried, barbequed, and smoked meats appear to have up to five times the risk of developing breast cancer (see also Muscle Tremors & Diet and Fast Food Tested for Carcinogens).

More than 85% of breast cancers are sporadic and attributable to long-term exposure to environmental carcinogens, such as those in the diet, through a multistep disease process progressing from non-cancerous to premalignant and malignant stages. Most cancer-causing agents are involved in either the initiation stage of cancer, triggering the initial DNA mutation (like radiation), or the promotion stage of cancer, promoting the growth of the tumor (certain hormones like IGF-1). But heterocyclic amines in cooked meat like PhIP are considered “three strikes” carcinogens because they are not only DNA-damaging mutagens and promote cancer growth, but also increase its metastatic potential by increasing tumor invasiveness.

Strike 1: By asking women undergoing breast reduction surgery about their meat cooking methods, researchers were able to directly correlate the number of DNA mutations found in breast tissue with the estimated dietary intake of these cooked meat carcinogens.

Strike 2: In my 4-min. video Estrogenic Cooked Meat Carcinogens I show that not only may these meat chemicals trigger the original cancer-causing mutation, they may also then promote the growth of the tumor. PhIP for example activates estrogen receptors on human breast cancer cells almost as powerfully as pure estrogen. Even at very low doses, the cooked meat chemical PhIP appears to drive the growth of breast cancer.

Strike 3: Click on the video pick above to see what affect these cooked meat carcinogens may have on the invasiveness and metastatic potential of human breast cancer. The growth hormone IGF-1 may also promote tumor progression and invasion (see IGF-1 as One-Stop Cancer Shop). IGF-1 is released by our liver in response to animal protein consumption regardless of how it’s cooked (why? See Higher Quality May Mean Higher Risk.) On the other hand, broccoli and Indian gooseberries may have both anti-proliferative and anti-invasive properties: Lung Cancer Metastases and Broccoli and Amla Versus Cancer Cell Invasion.

Most of the experiments on the cancer-causing effects of cooked meat chemicals were done on breast cells in a petri dish, though. How do we know these carcinogens make it not only into the breast after you eat cooked meat, but into the breast ducts where most breast cancers arise—so-called ductal carcinoma.  Researchers didn’t know for sure, until a study out of Canada measured the levels of PhIP in the breast milk formed in those ducts of nonsmoking women. The average concentration of the “three strikes carcinogen” they found in the breast milk of meat-eating women corresponded to significant cancer growth activation. One of the women was vegetarian, though, and none was detected in her breast milk.

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my videos for free by clicking here and watch my full 2012 year-in-review presentation Uprooting the Leading Causes of Death.

Adapted from Kathy Freston’s excellent post Anti-Breast Cancer: The ‘Three Strikes’ Carcinogen to Avoid

Image credit: jefferyloo / Flickr

Go Nuts for Breast Cancer Prevention
Prevent Breast Cancer by Any Greens Necessary
Pollutants in Californian Breast Tissue

Read more: Cancer, Diet & Nutrition, Eating for Health, General Health, Health, Videos, Women's Health, , ,

have you shared this story yet?

go ahead, give it a little love

Dr. Michael Greger

A founding member of the American College of Lifestyle Medicine, Michael Greger, M.D., is a physician, author, and internationally recognized speaker on nutrition, food safety, and public health issues. Currently Dr. Greger serves as the Director of Public Health and Animal Agriculture at The Humane Society of the United States. Hundreds of his nutrition videos are freely available at


+ add your own
7:02AM PST on Feb 25, 2013

good to know

2:05AM PST on Feb 25, 2013

Thank you :)

9:44PM PST on Feb 21, 2013

Ala M. says that we should: "Take out all the chemicals and hormones out of our meat diet and we will not develop any breast cancer. The Natives ate fresh grilled and barbequed meat and had no cancer."

What a novel concept! Nothing quite like common sense. Meat as it should be! Organic and safe. Same goes for veggies without the GMO and pesticides. Natural eating does wonders, along with exercise and proper portion sizes.

4:25PM PST on Feb 20, 2013

Thank you.

3:23PM PST on Feb 18, 2013

Very disturbing, but it's good to know.

9:41AM PST on Feb 18, 2013

So tragic...they murder animals for food, murder mice to test it, and now murder humans who consume it. Death begets death. Beget kindness instead.

7:54AM PST on Feb 18, 2013

All my older relatives lived into their 80's and fried or roasted all their meats, none had breast cancer. Back then we fried or roasted with the fat that came off the bacon we had for breakfast. I do not think our food supply is as safe today. I put a beef roast in the pan with a lid and 15 minutes later it is sitting in 1/4 inch of water that had been injected into the meat. When cooked it is half the size it was before putting it in the pan. All that water comes out of the meat and that never used to happen when I was a child.

5:19AM PST on Feb 18, 2013

I only eat meat rarely and what I do eat comes from local farms so I know what I'm getting and how the animals are raised. No factory-farm meat for me!

11:11AM PST on Feb 17, 2013


10:38AM PST on Feb 17, 2013

Thank you. I want to go vegan.

add your comment

Disclaimer: The views expressed above are solely those of the author and may not reflect those of
Care2, Inc., its employees or advertisers.

people are talking

Let's also remember that prunes are very sweet and, as such, highly caloric, as are most dried fruit…

They sure will give you a good 'run' for your money!

Thanks for sharing.

A person should only eat until they are still a bit hungry as it takes time for your stomach to tell…


Select names from your address book   |   Help

We hate spam. We do not sell or share the email addresses you provide.