The only downside of berries is the cost: My local supermarket was selling blueberries for $4.99 a pint the other day.

Ouch!

But while the price might sting, it's worth a little pain in the wallet to get your hands on some -- because ounce for ounce, berries are unmatched by anything else in the produce aisle.

I'm sure you already know about the famous antioxidants in berries, which can help protect you from the free radicals that are always trying to undermine your body.

And now, a new review of the research shows how berries can actually supercharge your brain and improve the way your neurons communicate. That adds up to better motor control and cognition and lower levels of dangerous inflammation -- all from a handful of delicious blueberries, blackberries, strawberries, or cranberries.

Grapes and blueberries in particular have been proven in studies to help improve the brain function in seniors, especially those already suffering from some impairment, according to the review published in the Journal of Agricultural and Food Chemistry.

Of course, none of this is all that new or surprising (it's a review of existing research, after all). An earlier study, for example, found that the polyphenolics in berries help the cells that clean up and recycle the toxic proteins that accumulate in the brain with age.

If that's not a good enough reason to boost your berry intake, consider this: Another new study shows that blueberries -- along with apples -- can slash your risk of diabetes.

Researchers say people who eat two or more servings of blueberries a week -- as well as those who eat five apples a week -- have a 23 percent lower risk of type 2 diabetes.

This was based on a food frequency questionnaire, and we know they're not exactly the most reliable form of research... so let's not get too excited.

But plenty of other more reliable studies back the benefits of berries. And that's especially true of blueberries, which are so rich in nutrients they're a superfood in a class of their own.

For all that, $4.99 a pint is a bargain -- because these little beauties are worth their weight in gold.