Dr. Oz Cancer Scare

CBS News reports that Dr. Mehmet Oz M.D., host of the Dr. Oz show and proponent of low-fat, high-fiber, vegetarian diets, has discovered that he has colon polyps.  As part of his show, he had Dr. Jonathan LaPook perform a colonoscopy on himself.  Dr. LaPook "didn't expect to find anything":

"He just might be the last person on earth people would expect to get a colon polyp," he wrote for CBSNews.com. "He's physically fit (he left me in the dust the last time we ran together), he eats a healthy diet, he doesn't smoke, and he has no family history of colorectal cancer or colon polyps."
But LaPook found something he hoped not to see, "a small adenomatous polyp that had the potential to turn into cancer over time."
"Statistically, most small polyps like his don't become cancer," wrote Lapook. "But almost all colon cancers begin as benign polyps that gradually become malignant over about 10-15 years."

Of course, the assumption here is that a low-fat, high cereal fiber diet that contains little or no red meat protects against colon cancer.  

LaPook says colon cancer is scary - this year it will likely strike 143,000 Americans and kill over 51,000 - but there is good news in all of this.
"Patients who smoke, eat diets high in red and processed meats, drink too much alcohol, don't exercise, and are obese are at increased risk of colorectal cancer," he wrote. "So Mehmet's healthy lifestyle may actually have protected him from having a bigger polyp - or even colorectal cancer by now."

As you can see, Dr. LaPook is so convinced that Dr. Oz's diet is "healthy" that he has to fit this anomoly into that world view.  Rather than wonder whether a low-fat high fiber diet is what caused this problem for Oz, he concludes that Oz would have been worse off if he had not been eating all those hearthealthywholegrains.

But if he did a little research, he would find out that colon cancer did not occur among Eskimos eating essentially no fiber and no whole grains.  He would learn that no research has provided any good evidence that red meat promotes colon cancer.  For example, in Red meat and colorectal cancer: A critical summary of prospective epidemiological studies, Alexander and Cushing report:

"Colinearity between red meat intake and other dietary factors (e.g. Western lifestyle, high intake of refined sugars and alcohol, low intake of fruits, vegetables and fibre) and behavioural factors (e.g. low physical activity, high smoking prevalence, high body mass index) limit the ability to analytically isolate the independent effects of red meat consumption. Because of these factors, the currently available epidemiologic evidence is not sufficient to support an independent positive association between red meat consumption and colorectal cancer."

Moreover, as I discussed in Fiber Fallacies, experimental studies suggest that a high fiber diet may promote polyp formation:

Many people think eating a high fiber diet will prevent colon cancer; but we not only have no proof or even weak evidence that ingestion of fiber prevents colon cancer, on the contrary we have experimental evidence indicating that diets high in fermentable fibers actually increase colonic cell proliferation of the type that leads to cancer.

Lupton et al reported that a diet high in fermentable fiber increased cecum size and large intestine length, and reduced pH and stimulated cell proliferation, in rat colons. [J. Nutr. 118: 840-845, 1988.]

Jacobs and Lupton found that when they fed rats a high fiber diet based on either oat bran, pectin, or guar, the yield of proximal colonic adenocarcinomas increased by 4.5 to 5 times over the fiber free level. [Cancer Research 46, 1727-1734, April 1986]

Mandir, Englyst, and Goodlad found that when they fed mice fiber in the form of bran or apple pomace, both fibers significantly increased cell proliferation, number of polyps, and tumor burden born by the mice. Both fibers increased polyp diameter, bran by 243% and apple fiber by 150%. [British Journal of Nutrition (2008), 100, 711–721]

According to the CBS News article, Dr. Oz told People Magazine:

"This was a shakeup for me...It's frustrating. Why did this happen to me? It forces you to question the assumptions you make about life."

Dr. Oz, since you are in the mood to question assumptions, I invite you to question the assumed safety and efficacy of the high fiber, low fat diet you endorse.