Blueberries may help prevent colon cancer and lower cholesterol
27 Marzo 2007
Along with scientists Nanjoo Suh, also of Rutgers, and Agnes Rimando of ARS, Reddy and his associates conducted a small pilot study to determine the effect of pterostilbene on colon cancer. The
study included 18 rats that were given a compound (azoxymethane) to induce colon cancer in a manner similar to human colon cancer development. Nine of the animals were then placed on a balanced
daily diet, while the other nine were given the same diet supplemented with pterostilbene (at a level of 40 parts per million).
At the end of an eight-week study period, the rats that were fed pterostilbene showed 57 percent fewer pre-cancerous lesions in their colon in comparison to the control group. Pterostilbene
also reduced colonic cell proliferation and inhibited certain genes involved in inflammation, both of which are considered colon cancer risk factors, the researchers say.
Meanwhile, blueberry skins may be the key to controlling cholesterol.
ARS chemist Agnes Rimando and collaborators found that feeding hamsters a diet extremely high in cholesterol, but supplemented with freeze-dried skins of rabbiteye blueberries, produced plasma
total cholesterol levels 37 percent lower than those of hamsters fed a control diet.
Levels of LDL–or “bad”–cholesterol were 19 percent lower in the blueberry-supplemented hamsters. Moreover, hamsters eating blueberry-enhanced food fared even better than hamsters augmented
with the lipid-lowering drug ciprofibrate. Those hamsters exhibited a 17 percent decline in cholesterol, and 15 percent decline in LDL.
Antioxidants may be responsible yet again for the results. Resveratrol and pterostilbene, oft cited for their antioxidant properties, are constituents of blueberry skins and can activate a
protein involved in the breakdown and import of fats.