Diabetes: eat your blueberries

A maturing Polaris blueberry

Drinking blueberry smoothies helped obese adults who were pre-diabetic improve insulin sensitivity, researchers report.

Sixty-seven percent of people who drank a blueberry smoothie twice a day for six weeks experienced a 10% or greater improvement in their insulin sensitivity, compared with 41% of people in the placebo smoothie group.

The findings suggest that compounds found in blueberries, which have also been found to improve heart health, may help people with prediabetes by making the body more responsive to insulin. What the biochemical chain reaction or cellular pathways might be remain unclear. Compounds in blueberries, called anthocyanins, have antioxidant properties, which may contribute to health benefits such as improved insulin sensitivity.

Wikipedia has more on the good stuff in blueberries.

Especially in wild species, blueberries contain anthocyanins, other antioxidant pigments and various phytochemicals possibly having a role in reducing risks of some diseases, including inflammation and certain cancers. 

Researchers have shown that blueberry anthocyanins, proanthocyanidins, resveratrol, flavonols, and tannins inhibit mechanisms of cancer cell development and inflammation in vitro. Similar to red grape, some blueberry species contain in their skins significant levels of resveratrol, a phytochemical.

Although most studies below were conducted using the highbush cultivar of blueberries (V. corymbosum), content of polyphenol antioxidants and anthocyanins in lowbush (wild) blueberries (V. angustifolium) exceeds values found in highbush species.

At a 2007 symposium on berry health benefits were reports showing consumption of blueberries (and similar berry fruits including cranberries) may alleviate the cognitive decline occurring in Alzheimer's disease and other conditions of aging.

A chemical isolated from blueberry leaves can block replication of the hepatitis C virus and might help to delay disease spread in infected individuals.

Feeding blueberries to animals lowers brain damage in experimental stroke. Research at Rutgers has also shown that blueberries may help prevent urinary tract infections.

Other animal studies found that blueberry consumption lowered cholesterol and total blood lipid levels, possibly affecting symptoms of heart disease.[34] Additional research showed that blueberry consumption in rats altered glycosaminoglycans which are vascular cell components affecting control of blood pressure.

A study soon to be published in the Journal of Agricultural and Food Chemistry found that supplementation with wild blueberry juice enhanced memory and learning in older adults, while reducing blood sugar and symptoms of depression.

All that in a little berry.