When I was about 18, one of my parents' best friends, Marge*, contracted breast cancer. Marge and her family had moved away when I was 10, but they stayed in touch with us and we visited each other about once a year or so. Because no one so close to me had ever had cancer, and cancer kills people, it was a Very Big Deal. She underwent a mastectomy and when the biopsy of her lymph nodes turned out clean, she opted out of chemotherapy in favor of a lifestyle based treatment. My father thought it was stupid, and that she was taking crazy risks with her health considering that she had a family who depended on her, but when he was down visiting Marge and her family he learned that she had chosen a vegan diet over chemotherapy after reading The China Study by Dr. T. Colin Campbell. Keep in mind that Marge and her husband Boris are both PhD's in agricultural engineering - with a strong emphasis in science, particularly agricultural science.
For them to go vegan was also a Very. Big. Deal.
The China Study is a book compiling both global epidemiological studies linking diet with certain cancers (Breast, colorectal, and prostate especially) and mechanistic-type animal model studies comparing the effect on cancer that diets based on the milk protein casein have to diets based on plant-derived foods and proteins. Marge and Boris talked my father (who has a PhD in genetics) into reading it while he was there. He did indeed read the book, and came back home a vegetarian - not quite a vegan, but avoiding milk products nonetheless. My mother was devastated (and to this day refuses to forgo meat), but I was thrilled. Now I had some solidarity in my carnivorous household, as I had been vegetarian for two years at the time.
The book describes a compelling link between animal protein, particularly dairy protein, and many diseases. Cancer, diabetes, heart disease...they are all very strongly -and globally- correlated to meat-based diets. Keep in mind that correlation never equals causation, but these correlations backed up with the animal studies and the sheer volume of epidemiological data truly paints a stark picture. Countries that eat the largest amount of meat and drink the most milk have the highest rates of a slew of different cancers.
However, one can be a vegetarian and still eat a very unhealthy diet. After all, mac-n-cheese is vegetarian. So are potato chips and Oreo cookies. The clincher for me to actually really think about the food I eat, and check for nutritive value beyond "well there are no animals in the ingredient list" has been the toxicology course I'm taking this semester. My professor has put a large emphasis on carcinogenesis - all heavily drawn from the most recent research from top labs, including his own lab's research projects. Lots of foods are full of carcinogens, including many vegetables and grains and herbs, but cooked meats are particularly "bad." Cooked meats are hosts to a smorgasbord of carcinogenic compounds. These compounds are often taken care of by the body's defense system, however the occasional DNA mutations that arise from the onslaught of carcinogenic chemicals accumulate over time...and they may be mutating DNA in key locations that control cellular laws. These particular DNA mutations can lead to altered cellular activity, and ultimately cancer.
Honestly, I know that few people can give up meat cold-turkey (pardon the pun). In fact, it would be silly to expect that, because to most people meat is tasty. I just wonder if it truly would be so difficult for most people now to simply eat meat in moderation. Eat meat a few times a week instead of a few times a day. Or enjoy smaller portions of meat and larger portions of vegetables and fruits - not just grains and starches like corn and potatoes (fries are not vegetables, regardless of whether school cafeterias would like them to be). I know the dairy, beef, pork, egg, poultry, etc. industries are not happy with these ideas and stand to lose a lot of money if Americans reduce their meat consumption even by a third. But the quality of life to be gained is worth it, and I would urge everyone to at least give it a try. Broccoli is not your enemy - it is full of fiber (preventing cancers of the gut) as well as chemicals that actively help your body fight carcinogenic compounds. So not only would you ingest fewer major carcinogens, but you would consume a greater volume of anti-carcinogens. It's a one-two punch K.O.!
Speaking of one-two punches, I found a video on Youtube that has little to do with cancer, but could lower your blood pressure and release feel-good chemicals into your brain...especially if you like kittens:
I really appreciated your post on cancer and diet. I read a very good article on cancer and diet a few weeks ago. I would like to know what you think, in light of what you posted on cancer and diet. Here is the abstract:
ReplyDeleteHo, V. W., Leung, K., Hsu, A., et al., (2011). A Low Carbohydrate, High Protein Diet Slows Tumor Growth and Prevents Cancer Initiation. Cancer Research.
Abstract
Since cancer cells depend on glucose more than normal cells, we compared the effects of low carbohydrate (CHO) diets to a Western diet on the growth rate of tumors in mice. To avoid caloric restriction–induced effects, we designed the low CHO diets isocaloric with the Western diet by increasing protein rather than fat levels because of the reported tumor-promoting effects of high fat and the immune-stimulating effects of high protein. We found that both murine and human carcinomas grew slower in mice on diets containing low amylose CHO and high protein compared with a Western diet characterized by relatively high CHO and low protein. There was no weight difference between the tumor-bearing mice on the low CHO or Western diets.
Additionally, the low CHO-fed mice exhibited lower blood glucose, insulin, and lactate levels. Additive antitumor effects with the low CHO diets were observed with the mTOR inhibitor CCI-779 and especially with the COX-2 inhibitor Celebrex, a potent anti-inflammatory drug. Strikingly, in a genetically engineered mouse model of HER-2/neu–induced mammary cancer, tumor penetrance in mice on a Western diet was nearly 50% by the age of 1 year whereas no tumors were detected in mice on the low CHO diet. This difference was associated with weight gains in mice on the Western diet not observed in mice on the low CHO diet. Moreover, whereas only 1 mouse on the Western diet achieved a normal life span, due to cancer-associated deaths, more than 50% of the mice on the low CHO diet reached or exceeded the normal life span. Taken together, our findings offer a compelling preclinical illustration of the ability of a low CHO diet in not only restricting weight gain but also cancer development and progression. Cancer Res; 71(13); 4484–93. ©2011 AACR.
Great post,
Jerry