Blueberries good for you.. of course we knew that

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Eating blueberries slashes colon cancer risk by 57 percent, animal

study finds

by Mike

A compound found in blueberries shows promise of preventing colon

cancer, according to a new study. Scientists at Rutgers University and

the U.S. Department of Agriculture conducted a joint study on animals,

and found that the compound -- called pterostilbene -- lessened

pre-cancerous lesions and inhibited genes involved in inflammation.

Researchers presented the study at the American Chemical Society's

annual meeting in March.

" This study underscores the need to include more berries in the diet,

especially blueberries, " said study leader Bandaru Reddy, Ph.D., a

professor in the chemical biology department at Rutgers. Although the

blueberry compound won't cure colon cancer, it represents a strategy

for preventing the disease naturally, said Reddy, who specializes in

studying the relationship between nutrition and colon cancer.

The researchers studied 18 rats in which colon cancer had been induced

in a manner similar to human colon cancer development. All of the

animals were placed on a balanced diet, with half of the animals'

diets supplemented with pterostilbene. After eight weeks, the rats fed

pterostilbene had 57 percent fewer pre-cancerous colon lesions

compared to the control group. The researchers also noted that

pterostilbene inhibited certain genes involved in inflammation,

considered a colon cancer risk factor.

Colon cancer is the second leading cause of cancer death in the U.S.

It has been linked to a high intake of saturated fats and calories

common in Western diets. Pterostilbene may be able to reverse this

process, possibly by lowering lipids, Reddy said.

Reddy cited a recent study by co-author Agnes Rimando of the

Department of Agriculture. Rimando demonstrated that blueberries,

particularly their skins, can lower cholesterol when fed to animals.

Some thirty different species of blueberries are native to North

America. The berries are rich in anthocyanins, widely recognized for

their antioxidant qualities. Blueberries are also a good source of

ellagic acid, which blocks metabolic pathways that can lead to cancer.

Pterostilbene, an Active Constituent of Blueberries, Suppresses

Aberrant Crypt Foci Formation in the Azoxymethane-Induced Colon

Carcinogenesis Model in Rats

Nanjoo Suh1, Shiby 1, Xingpei Hao1, Barbara Simi1, Hang Xiao1,

Agnes M. Rimando2 and Bandaru S. Reddy1

Authors' Affiliations: 1 Department of Chemical Biology, Ernest

School of Pharmacy, Rutgers, The State University of New Jersey,

Piscataway, New Jersey and 2 U.S. Department of Agriculture,

Agricultural Research Service, Natural Products Utilization Research

Unit, University, Mississippi

Requests for reprints: Nanjoo Suh, Department of Chemical Biology,

Ernest School of Pharmacy, Rutgers, The State University of New

Jersey, 164 Frelinghuysen Road, Piscataway, NJ 08854. Phone:

732-445-3400, ext. 226; Fax: 732-445-0687; E-mail:

nsuh@... or Agnes M. Rimando, United States Department of

Agriculture, Agricultural Research Service, Natural Products

Utilization Research Unit, PO Box 8048, University, MS 38677. Phone:

662-915-1037; Fax: 662-915-1035; E-mail: arimando@....

Purpose: Epidemiologic studies have linked the consumption of fruits

and vegetables to reduced risk of several types of cancer. Laboratory

animal model studies have provided evidence that stilbenes, phenolic

compounds present in grapes and blueberries, play a role in inhibiting

the risk of certain cancers. Pterostilbene, a naturally occurring

stilbene from blueberries, was tested for its preventive activity

against colon carcinogenesis.

Experimental Design: Experiments were designed to study the inhibitory

effect of pterostilbene against the formation of azoxymethane-induced

colonic aberrant crypt foci (ACF) preneoplastic lesions in male F344

rats. Beginning at 7 weeks of age, rats were treated with azoxymethane

(15 mg/kg body weight s.c., once weekly for 2 weeks). One day after

the second azoxymethane treatment, rats were fed experimental diets

containing 0 or 40 ppm of pterostilbene. At 8 weeks after the second

azoxymethane treatment, all rats were sacrificed, and colons were

evaluated for ACF formation and for inhibition of inducible nitric

oxide synthase (iNOS) and proliferating cell nuclear antigen. Effects

on mucin MUC2 were also determined.

Results: Administration of pterostilbene for 8 weeks significantly

suppressed azoxymethane-induced formation of ACF (57% inhibition, P <

0.001) and multiple clusters of aberrant crypts (29% inhibition, P <

0.01). Importantly, dietary pterostilbene also suppressed

azoxymethane-induced colonic cell proliferation and iNOS expression.

Inhibition of iNOS expression by pterostilbene was confirmed in

cultured human colon cancer cells.

Conclusions: The results of the present study suggest that

pterostilbene, a compound present in blueberries, is of great interest

for the prevention of colon cancer.