cancer from meat?

[Guest guest]

I'm copying into this message an announcement I received about a speaker on

cancer caused by meat. Any comments, gang? Obviously the speech is more

relevant to the Portland group, but I seek all of your thinking on this.

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*Meat, Meat-Cooking Carcinogen, and Cancer*

Rashmi Sinha

*of the National Cancer Institute*

*Sigma Xi Distinguished National Lecturer*

*Thursday January 26, 2006, 7:15pm*

* Center 327/8/9, Portland State University*

Free admission; the public is welcome

Free parking in Parking 2 after 7 pm

Co-sponsor: PSU Department of Anthropology

Diets containing substantial amounts of red or preserved meats may increase

the

risk of various cancers. This association may be due to a combination of

factors,

such as content of fat, protein, and iron, and/or meat preparation (e.g.

cooking or preserving methods).

Laboratory results have shown that meats cooked at high temperatures contain

heterocyclic amines (HCAs) and

polycyclic aromatic hydrocarbons (PAHs), which are mutagenic and

carcinogenic in animals. To investigate the

role of these compounds we have created separate databases for mutagenic

activity, HCAs, and PAHs, which we

have used in conjunction with a validated meat-cooking food frequency

questionnaire (FFQ). The role of meat

type, cooking methods, doneness levels, and meat-cooking mutagens has been

examined in both case-control

studies and prospective cohort studies. The results from these studies are

mixed for different sub-types of meat,

cooking methods, and doneness levels, as well as for estimated intakes of

mutagenic activity, HCA, and PAHs.

An additional role of red meat in colon cancer could be through the

contribution to *N*-nitroso compound (NOC) exposure.

Humans can be exposed to NOCs by exogenous routes (from processed meats in

particular) and by endogenous routes.

Endogenous exposure to NOCs has been shown to be dose-dependently related to

the amount of red meat in the diet.

Recent work suggests that heme iron in red meat may explain the high levels

of endogenous NOC, levels equivalent to

those found in cigarette smoke.

In summary, even though the results from case-control studies lend support

to an association between meat- cooking

mutagens and cancer, other larger prospective studies are not consistent.

Other components of red meat, such as heme

iron, fat, nitrite/nitrosamine need to be explored further. This

presentation will examine the current epidemiologic

knowledge in relation to meat-related mutagens and will evaluate the types

of studies that may be required in the

future to clarify the association of meat and human cancers.

Rashmi Sinha is an investigator in the Nutrition Epidemiology Branch,

Division of Cancer Epidemiology and

Genetics, at the National Cancer Institute. Research interests include the

role of meat, heterocyclic aromatic amines,

and polycyclic aromatic hydrocarbons in cancer etiology, as well as the

interaction of genetic susceptibility and

nutrition in cancer. Other interests include vitamins A, C and E and cancer,

DDT and breast cancer, and

development of biomarkers of diet. Sinha's honors include the National

Institute of Health Award of Merit and the

Technology Transfer Award. Sinha is associate editor of the journal *Cancer

Epidemiology, Biomarkers and*

*Prevention*, is a reviewer for numerous journals, and has served on a

variety of professional committees and boards.

*Chapter Website*

The Columbia-Willamette Chapter's website is

<www.sigmaxi.org/chapters/web/CWC/index.htm>. It posts announcements of

upcoming Sigma Xi lectures,

Chapter events such as the Student Research Symposium, and information about

the Chapter.