By Bob Condor

One of a summer day’s simple delights is a slice of water. OK, maybe two or three slices. Who knew that watermelon might one of the healthiest items at the picnic too?

If you are like most of us, you would consider watermelon healthy because it is a delicious way to hydrate, given that it is 92 percent water. But food scientists like Penelope Perkins-Veazie have discovered the juicy red fruit is loaded with antioxidants to fortify the body, especially carotenoids that can offset cell damage caused by chemicals and sun.

Oh, even more reasons to bite into watermelon on a July or August day. Watermelon is especially high in lycopene, which is more typically associated with cooked tomatoes. Lycopene first made the news as a protector against prostate cancer in men. It has since been rated as equally potent for preventing heart disease, high blood pressure and erectile dysfunction (see tomorrow's post about ED).

Seeing the potential for the picnic favorite melon, Perkins-Veazie has drilled down even more into the nutrient power of watermelons with recent studies. One project analyzed mini-watermelons available at markets for about the past two years. The fruit is about six inches in diameter and perfect for singles or couples.

Perkins-Veazie tested 15 different lines of mini-watermelons and discovered a good number of them have even more with lycopene than the larger melons we all remember from summers past.

But there is one catch to the lycopene bonanza. Don’t refrigerate the melon. Perkins-Veazie and fellow USDA researcher Julie Collins discovered that icing down a watermelon inhibits the antioxidants while keeping it a room/air temperature

optimized the power-nutrient content.

What's more, the food scientists discovered that room-temperature watermelons stored for two weeks after deemed ripe to pick by growers contained 40 percent more lycopene and 50 to 140 percent more betacarotene than just-picked melons.

The researchers documented that lycopene continues to be manufactured in the melon. When you hear vegetarians or raw food enthusiasts talk about “live foods,” this sort of lycopene and nutrient production is an example of what they mean.

One note: Mass-harvested melons from big growers are typically stored for two to three weeks at 55 degrees, which isn’t doesn’t quell the lycopene as much as the standard 37 to 41 degrees of a fridge but still is down from the optimum of 70 degrees or room temperature.

So, when possible, buy your watermelons from local or small growers, then keep them out for a while at home. Maybe look for mini-melons if you don’t have big crowd on hand. Only once you have cut melon should it go into the fridge.

Of course, who can’t make room for another slice or bowl of melon balls?

“Bob Condor is the Daily Health Blogger for Barton Publishing . He is also the Living Well columnist for the Seattle Post-Intelligencer . He covers natural health and quality of life issues and writes regularly for national magazines, including Life, Esquire, Parade, Self, and Outside. He is a former syndicated health columnist for the Chicago Tribune and author of six books, including “The Good Mood Diet” and “Your Prostate Cancer Survivors' Guide.” He lives in the Pacific Northwest with his wife and two 11-year-old kids.