Give Thanks: Cranberries, Best of Super Foods

Here's something to be thankful for. Amid the potentially deadly turkey dressing, gravy and pie on your Thanksgiving Day table, there will likely be one of the healthiest foods on the planet. In fact, if it were just discovered today, it would probably be ranked among the top medical discoveries of the year, if not the decade.

We're talking cranberries here, those unpretentious red berries that scientists have been saying for years are nearly miraculous in terms of what they can do for our health. And now they are coming up with a better understanding of just how cranberries accomplish their magic.

But first, here's the lowdown:

  • The cranberry is the No. 1 antioxidant, containing the highest concentration of phenols, a type of antioxidant that is thought to reduce the risk of chronic diseases such as cancer, stroke and heart disease (University of Scranton).
  • Cranberries contain a compound that helps prevent metastasis, the spread of cancer to other parts of the body (University of Massachusetts-Dartmouth). Cranberries may also improve chemotherapy for ovarian cancer (Rutgers University).
  • Cranberry juice, long recognized for its ability to lessen urinary tract infections, also works against a number of gastrointestinal viruses (St. Francis College).
  • The cranberry has several antioxidants (flavonoids) that fight off the bacterium that causes tooth decay (University of Rochester School of Medicine and Dentistry).
  • And there is considerable evidence that cranberries can reduce the damage from stroke (University of Massachusetts-Dartmouth); improve the health of the heart, at least in pigs (University of Wisconsin-Madison); and work like antibiotics on E. coli, a class of microorganisms responsible for human illnesses ranging from kidney infections to gastroenteritis (Worcester Polytechnic Institute).

    Phew. That's a lot, especially for a small berry that is almost lost in the avalanche of food that spills over the American dinner table each November. But how, one might ask, does it do all that?

    Scientists at the Worcester Polytechnic Institute in Worcester, Mass., have been hammering away at that for years, and they have come up with an explanation for how cranberries ward off urinary tract infections.

    Researchers have long suspected that the berries must do something to stop harmful bacteria from latching on to the lining of the urinary tract.

    Terri Camesano, associate professor of chemical engineering at WPI, heads a team of researchers who have found that cranberry juice causes chemical changes in the bacteria. Those changes work in several ways to create a barrier that keeps the bacteria from even getting close to the lining. For example, cranberry juice causes tiny tendrils on the surface of E. coli to become compressed, reducing the bacteria's ability to latch on to the lining.

    If the bacteria can't attach to the sides of the tract, it can't do its damage. The research suggests that the juice is extremely powerful, even in very diluted stages. Only a 5 percent solution is required to reduce the bacteria's ability to latch on to the urinary tract.

    Of course, most of this is not new. According to Darren Lynch of Beth Israel Medical Center in New York, cranberries have been used since at least the 17th century to treat blood disorders, stomach ailments, loss of appetite, scurvy and cancer. When the pilgrims first arrived in this country, they found that American Indians were using the berries to treat bladder and kidney ailments.

    The pilgrims called the fruit "craneberry" because the stem and flower looked a little like the head, neck and beak of a crane.

    So, with all this good stuff that cranberries do for us, is it possible to overdo it? Along with the pie and the turkey and the stuffing, can we overdose on cranberries?

    According to Lynch, the cranberry is a "safe, well-tolerated herbal supplement that does not have significant drug interactions."

    But that doesn't mean it isn't possible to get too much of a good thing. If you pig out on cranberry juice, scientists say, you may wind up with a stomachache and diarrhea. And its role in such things as fighting cancer is so poorly understood that much caution needs to be exercised.

    But cranberries are still better than an overdose of gravy. Maybe not as tasty, but healthier.

    Lee Dye is a former science writer for the Los Angeles Times. He now lives in Juneau, Alaska.