Purple Power
by Terry Bates
When I drink a glass of Concord grape juice, I really don't think about the concentration of anthocyanins or the antioxidant capacity in my glass of purple liquid. I just like the taste.
However, when I meet new people and promote New York grape juice (as I know you all do), I tell them that Concord juice tastes good and is good for you. Most of the time, my new acquaintance simply smiles and nods and avoids a detailed discussion with an overzealous viticulturalist. Other times, I am challenged about my healthful comments promoting Concord juice.
I am asked: Why is grape juice healthy? I thought free radicals were a political party in Washington D.C. What does the color purple in grapes have to do with preventing a heart attack? You may have been asked similar questions, so I decided to dust off my plant physiology and biochemistry textbooks to compose some answers.
The Bad Guys: Free Radicals
Although free radicals sound like they are something from out of a sci-fi movie, they are quite common in biological systems--including your own body. Free radicals are atoms or molecules that have at least one unpaired electron, which makes them very reactive with other molecules.
In some respects free radicals can be good in energy producing reactions and in killing harmful bacteria. In other respects free radicals can be bad because they react with and break down the good molecules in your body, such as DNA, proteins, enzymes, and lipids. The attack of free radicals is called oxidative stress and can cause cells to lose both structure and function.
So where do free radicals come from? Free radicals are products of normal cellular oxidative metabolism. As you may remember from high school biology and chemistry, oxygen plays a role in receiving or donating electrons in oxidation/reduction process.
In biological systems, molecules such as peroxyl radicals, hydroxyl radicals, and superoxide radicals contain oxygen with an extra electron that is highly reactive with other molecules. Your body naturally tries to repair the tissues damaged by free radicals, but if the free radicals go unchecked they may cause more permanent damage leading to health problems: heart disease, cancer, accelerated aging.