Saturday, April 17, 2010

Fruits and vegetables are food for life

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Do Fruits and Vegetables Prevent Cancer?
Sunday, 11 April 2010

The Journal of the National Cancer Institute (JNCI) has published a paper that denies a major role to fruit and vegetable consumption in the prevention of cancer. Since this study contradicts many other studies, as well as a long-term US government recommendation ("5 per day"), it has gotten a lot of press. At this writing, there have been 520 news articles, almost all of them negative. "Simply eating your five a day will not protect you against cancer," is how the Independent (U.K.) phrased it.

However, there are several questions that need to be addressed about this study. Here are some initial thoughts. I hope to present some further thoughts after my visit with Prof. Colin Campbell this summer.

First, according to this European Prospective Investigation Into Cancer and Nutrition (EPIC) study, if the subjects had increased their fruit and vegetable intake by just 150 grams per day, they would have reduced their risk of getting cancer by 2.6 percent (men) and 2.3 percent (women). Now, 150 grams is the weight of one apple. In the United States in 2009 there were 766,130 cases of cancer in men and 713,220 cases in women, for a total of 1,479,350. Thus, by the study's own figures, one small apple or a handful of grapes could prevent 19,919 US cases of cancer in men plus 16,404 cases in women, for a total of 36,323 people. That's about the capacity of Fenway Park in Boston, where the Red Sox hold forth. So instead of minimizing the results (as virtually every media outlet chose to do) the authors of these articles could have put a positive spin on the EPIC findings. After all, is it a small thing to keep more than 36,000 Americans from getting cancer at such a minimal cost?

Looked at in another way, the patients in the study were divided up into five groups or "quintiles."

Quintile 1 consumed 0 to 226 grams per day (i.e. less than eight ounces maximum)
Quintile 2 consumed between 227-338 grams per day.
Quintile 3 consumed between 339-462 grams per day.
Quintile 4 consumed between 463-646 grams per day.
Quintile 5 consumed more than 647 grams per day (i.e., a minimum of 23 ounces)

The difference in the Hazard Ratio (i.e., the risk) of cancer between Quintile 1 and Quintile 5 was 11 percent. Thus, if everyone in the US adopted a diet in which they ate over a pound (23 ounces) of fruits and vegetables per day, the cancer incidence would drop from its present-day 1,479,350 for a savings of many thousands of cases of cancer.

The European Prospective Investigation Into Cancer and Nutrition (EPIC) encourages us to think internationally. The World Health Organization (WHO) has estimated that there are at least 12 million new cancers diagnosed worldwide (Science Digest 2008). According to the EPIC study, conversion to a moderately high fruit-and-vegetable diet could ideally save hundreds of thousands of people from getting cancer each year. This astonishing fact was hardly conveyed by the negative press reports on the EPIC study.

To be concluded, with references, next week

--Ralph W. Moss, Ph.D.

To simplify complications is the FIRST essential of success. (Click here) 

Do Fruits and Vegetables Prevent Cancer? - Part II

Sunday, 18 April 2010

Advocates of stricter forms of a vegetarian diet point out that changes of a few ounces are not likely to make much of a difference in cancer occurrence. One needs to make drastic changes, they say, in order to combat as intractable a disease as cancer.

Dr. Pam Popper, director of the Wellness Forum of Columbus, Ohio, suggests that these changes should consist of (a) the elimination of dairy products, (b) the reduction or elimination of all other animal foods (the upper limit being 10 percent of calories), (c) reduction of fat and elimination of oils, and (d) consumption of a diet composed of high-fiber, nutrient-dense, whole plant foods. She points to studies that indicate that such a diet can not only prevent cancer but can actually stop the progression of various disease states (Popper 2010).

Popper cites Cornell Professor Colin Campbell's fascinating book, The China Study, to show that animal protein can be a powerful cancer promoter. She also claims that dietary fats, including monounsaturated and polyunsaturated fats, are a significant factor in cancer risk. Indeed, in 1991, Kenneth K. Carroll concluded: "Total dietary fat correlates with cancer incidence and mortality at least as well as does any particular type of fat" (Carroll 1991). The consumption of dairy products has been linked to several forms of cancer, particularly tumors of the prostate (Chan 2001), although there is hardly unanimity on this idea, even in vegetarian circles.

My friend Ann Fonfa ( makes a good point that the topmost consumers of fruits and vegetables in the study (Quintile 5) consumed as little as 647 grams per day (i.e., a minimum of 23 ounces). This is not very much! Right now I have a single sweet potato in my refrigerator that weights 586 grams, itself almost the uppermost limit of daily consumption in the EPIC study. There was no attempt made to isolate those people who were really getting a high proportion of their daily calories from fresh fruits and vegetables (and no consideration was given to the question of organic food, either).

None of these factors were considered in the EPIC study just released. What would have been the effect if strict vegans (no eggs, dairy, fish or meat) had been considered as a separate category. That might have provided very positive results, which probably would have proven more meaningful than the data that emerged from the EPIC study.

--Ralph W. Moss, Ph.D.

To simplify complications is the FIRST essential of success. (Click here) 

Boffetta P, et al. Fruit and vegetable intake and overall cancer risk in the European Prospective Investigation Into Cancer and Nutrition (EPIC). J Natl Cancer Inst. 2010;102:1-9 Advanced access published April 6, 2010.

Campbell, Colin. The China Study. Dallas: Benbella Books, 2006.

Chan JM and Giovannucci EL. Dairy products, calcium and vitamin D and risk of prostate cancer. Epidemiol Revs. 2001;23:87-92

Carroll KK. Dietary fats and cancer. Am J Clin Nutr. 1991;53:1064S-7S.

Cancer Projected To Become Leading Cause Of Death Worldwide In 2010. Science Daily, December 8, 2008. Accessed:

Popper, Pam. Personal communication. April 7, 2010.
 To simplify complications is the FIRST essential of success. (Click here) 

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