Although many women fear breast cancer, and rightly so, the greatest risk to health for both men and women comes not from cancers, but from cardiovascular disease. In the figure below, you can see that the leading cause of death in the U.S. is cardiovascular disease followed by cancer.1 In both men and women cardiovascular disease plus cancer cause a little over 60% of all deaths from all causes combined. The good news here is that the Paleo Diet contains numerous nutritional elements which can greatly reduce your risk of contracting both of these diseases.
There is no doubt that breast cancer is a serious illness which in many cases can be life threatening. In the two charts below, I have listed the top 10 causes of cancer deaths in the U.S. in 2007.5 Note that for both men and women, lung cancer is responsible for nearly twice as many fatalities as the next leading cancer deaths (breast cancer for women and prostate cancer for men). Almost all lung cancer is caused by smoking and consequently is entirely preventable by simply eliminating this nasty habit.
When we consider breast cancer from an evolutionary perspective,7 a most remarkable revelation surfaces – it was rare or non-existent in historically studied hunter gatherers and other less westernized peoples>11, 13, 22 Similar observations have been consistently noted for almost all of the other common modern cancers (lung, prostate, colorectal, pancreatic, leukemia and ovarian) listed in the charts above.2, 4, 11-13, 15, 17, 18, 20, 22, 23 Further, documented cancers from the fossil record in pre-agricultural people are extremely rare or nonexistent.3, 4, 10 Some of the most convincing evidence demonstrating that cancer is a disease of modern civilization comes from studies of the Inuit (Eskimo) people as they made the transition from their Stone Age way of life to the Space Age in less than two generations.
Here is a representative quote from an article on Eskimo health that appeared in The Canadian Medical Association Journal from May of 1936,23 “In the Western Arctic Dr. Urquhart has as yet not met with a single case of cancer in the seven years of his practice. Cancer must be extremely rare in the Eastern Arctic also.” Similar observations come from yet another frontier physician, Dr. Samuel Hutton, who treated non-westernized Inuit people in Labrador from 1902 to 1913;23 “Some diseases common in Europe have not come under my notice during a prolonged and careful survey of the health of the Eskimos. Of these diseases the most striking is cancer. I have not seen or heard of a case of malignant new growth in an Eskimo.” As the Inuit people became more and more westernized and began to replace their traditional foods with processed foods, their relative immunity to cancer diminished.8, 14 In a paper published in 1984, Drs. Hildes and Schaefer13 examined cancer rates in the Inuit from 1950 to 1980 and noted, “The most frequent tumours in the most recent period studied were lung, cervical and colorectal cancers. Breast cancer was absent before 1966 and was found in only 2 of 107 Canadian Inuit women stricken with cancer from 1967 to 1980, whereas the recent rates in the longer-acculturated Inuit of Alaska and Greenland have approached those prevailing in modern Western women.”
The virtual absence of breast cancer and other common western cancers is not entirely restricted to the Inuit. The world famous Nobel prize winning physician, Dr. Albert Schweitzer, commented,22 “On my arrival in Gabon, in 1913, I was astonished to encounter no case of cancer…I cannot, of course, say positively that there was no cancer at all, but, like other frontier doctors, I can only say that if any cases existed they must have been quite rare. This absence of cancer seemed to me due to the difference in nutrition of the natives as compared with the Europeans…In the course of the years, we have seen cases of cancer in growing numbers in our region. My observations incline me to attribute this to the fact that the natives were living more and more after the manner of the whites…” Dr. Schweitzer got it right. The virtual absence of breast, prostate, colorectal and other common western cancers in the hunter gatherers of Gabon had everything to do with their diet.
The Paleo Diet maintains multiple nutritional characteristics which will help to protect you against breast and other common western cancers. By now, you are well aware that the Paleo Diet is a low glycemic index, low glycemic load diet. A recent meta analysis involving 10 epidemiological studies and more than 575,000 subjects by Drs. Dong and Qin clearly showed that high glycemic index diets increased the risk for breast cancer.6 Similar results were observed in an even larger meta analysis by Dr. Barclay and colleagues from the University of Sydney.26
It is not only the Paleo Diet’s low glycemic index and load that will protect you from breast cancer, but also its rich omega 3 fatty acid content and low levels of vegetable oils. In tissue and animal models of mammary cancer, omega 6 fatty acids from vegetable oils stimulate cancer growth, whereas long chain omega 3 fatty acids from fish oil inhibit it.29 Further a large meta analysis by Dr. Saadatian-Elahi and co-workers showed a significant protective effect of omega 3 fatty acids on breast cancer risk.21 Further, omega 3 supplements in humans can increase the concentration of these healthful fats in breast tissue, similar to Eskimo women who were free of breast cancer until they became westernized.24
The Paleo Diet is a milk and dairy free diet, and meta analyses have demonstrated that milk drinking increases women’s lifetime risk for ovarian cancer.27 For men, milk drinking increases the lifetime risk for prostate cancer.28
Finally, the Paleo Diet is exceedingly rich in fresh fruits and veggies.30 These foods are Mother Nature’s best medicine, and meta analyses of population studies confirm that fresh fruits and vegetables protect women from breast and many other cancers.9, 16, 19, 25 Any way you look at it, the Paleo Diet is a good remedy to prevent cancer.
Loren Cordain, Ph.D., Professor Emeritus
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19. Riboli E, Norat T. Epidemiologic evidence of the protective effect of fruit and vegetables on cancer risk. Am J Clin Nutr. 2003 Sep;78(3 Suppl):559S-569S.
20. Riveros M. First observation of cancer among the Pampidos (Chulupi) Indians of the Paraguayan Chaco. Int Surg 1970;53:51-55.
21. Saadatian-Elahi M, Norat T, Goudable J, Riboli E. Biomarkers of dietary fatty acid intake and the risk of breast cancer: a meta-analysis. Int J Cancer. 2004 Sep 10;111(4):584-91
22. Stefansson V. Cancer: Disease of Civilization? Hill and Wang, NY, 1960.
23. Urquhart JA. The most northerly practice in Canada. Can Med Assoc J. 1935;33:193-196.
24. Yee LD, Lester JL, Cole RM, Richardson JR, Hsu JC, Li Y, Lehman A, Belury MA, Clinton SK. Omega-3 fatty acid supplements in women at high risk of breast cancer have dose-dependent effects on breast adipose tissue fatty acid composition. Am J Clin Nutr. 2010 May;91(5):1185-94.
25. Zhang CX, Ho SC, Chen YM, Fu JH, Cheng SZ, Lin FY. Greater vegetable and fruit intake is associated with a lower risk of breast cancer among Chinese women. Int J Cancer. 2009 Jul 1;125(1):181-8.
26. Barclay AW, Petocz P, McMillan-Price J, Flood VM, Prvan T, Mitchell P, Brand-Miller JC. Glycemic index, glycemic load, and chronic disease risk–a meta-analysis of observational studies. Am J Clin Nutr. 2008 Mar;87(3):627-37
27. Genkinger JM, Hunter DJ, Spiegelman D, et al. Dairy products and ovarian cancer: a pooled analysis of 12 cohort studies. Cancer Epidemiol Biomarkers Prev. 2006 Feb;15(2):364-72
28. Gao X, LaValley MP, Tucker KL. Prospective studies of dairy product and calcium intakes and prostate cancer risk: a meta-analysis. J Natl Cancer Inst. 2005 Dec 7;97(23):1768-77.
29. Dilprit Bagga D, Capone S, Wang H, Heber D, Lill M, Chap L, Glaspy JA. Dietary Modulation of Omega-3/Omega-6 Polyunsaturated Fatty Acid Ratios in Patients With Breast Cancer. J Natl Cancer Inst. 1997; 89(15):1123-1131.