02/12/2015 11:55 am ET Updated Apr 14, 2015

Chocolate: A Treat for Valentine's Day, or the Cure for Aging Brains?

It doesn't take much to persuade me to eat chocolate. Chocolate is my favorite treat, and to me, all worthwhile desserts are nothing more than chocolate delivery systems.

So I welcome chocolate in starring roles in eat-for-your-health studies.

Last fall, a neat study published in Nature Neuroscience showed that healthy 50- to 69-year-olds who drank a mixture rich in cocoa's flavonols for three months improved their cognitive function. The 37 people in the study also underwent functional MRI imaging after ingesting the cocoa drink that found greater activity in the area of the brain called the dentate gyrus, an area associated with memory.

In a new study in the American Journal of Clinical Nutrition researchers gave 90 elderly people who don't have cognitive impairment one of three cocoa drinks: high, medium or low in flavonol. Cognitive function was tested at the beginning and after eight weeks of daily drinks. The groups that drank the intermediate- and high-flavonol drinks showed improved cognitive performance and improvement in some mental tasks. On top of that, blood pressure and insulin resistance also improved in the high cocoa flavonol group.

These same researchers conducted a similar study with older people that already suffered mild cognitive impairment. In that study too, those of the 90 people that were randomly assigned to drink the intermediate and high-cocoa flavonol drinks showed improved verbal fluency and higher speed of mental processing than those on the low-flavonol drink.

Chocolate for your brain?

These studies provide further evidence that food can affect your health and well-being, even your intellect.

But does it prove that eating chocolate strengthens your brain?

Getting the amount of flavonols that were useful in the study group from chocolate would involve eating so much chocolate that whatever protection you'd gain from these beneficial molecules, you'd lose from the harms associated with sugar and calorie overload. The people in the high-cocoa group consumed the equivalent of what's in 6 ounces of dark chocolate (~900 calories), and forget about milk chocolate -- it has much less flavonols -- you'd need 3 pounds (thousands of calories) a day.

Reasonable consumption of chocolate would place you in the low-flavonol arm of the experiment, at best.

If you're wondering why the sudden scientific interest in chocolate, note that the studies cited above were partially funded by Mars (the chocolate maker). That's not to say that the results are anything but accurate and independent of the funding source.

But maybe when you study a plant food and fund that research, you'll find many positive effects and headlines will announce it as a new cure. It's very likely that investing in research on any traditional plant food would have led to equally encouraging results. After all, there are flavonols similar to the one in cocoa in tea, onions, kale, grapes and apples. That's why we should eat our plants. And if you want to help protect your brain from aging the best piece of advice remains the same: exercise regularly!

Dr. Ayala