An antioxidant comparison of some of the most common fruits found that the little red berry — in its pure form — contained the highest quantity of disease-fighting phenols, a type of antioxidant that is thought to reduce the risk of chronic diseases such as cancer, stroke and heart disease.
The study is scheduled to appear in the November 19 issue of the Journal of Agricultural and Food Chemistry, a peer-reviewed journal of the American Chemical Society, the world’s largest scientific society. It was published in the Web edition of the journal on Oct. 3.
The study represents the most comprehensive investigation to date of the quantity and quality of antioxidants in fruits, says lead researcher Joe Vinson, Ph.D., a chemist with the University of Scranton in Scranton, Penn.
“Cranberries are one of the healthiest fruits. I think that people should eat more of them,” says Vinson. Although researchers have known for years that cranberries are high in antioxidants, detailed data on their phenol content in comparison to other fruits was unavailable until now, he says.
Vinson measured the total phenol content in each of 19 fruits commonly consumed in the American diet. Gram for gram, cranberries had the highest phenol content. On the basis of serving size, cranberries also ranked first, he says.
Vinson and his associates are now conducting animal studies to determine if the high antioxidant levels of cranberries protect against the development of atherosclerosis, or hardening of the arteries, a condition that can lead to heart attacks and strokes. The researchers eventually plan to conduct human studies to determine if supplements of the fruit would offer heart protection, he says.
The study underscores government health recommendations that people should eat more fruits and vegetables to help maintain a healthy diet and lifestyle, he added.
Although studies have shown that antioxidants from both sources appear to offer some degree of health protection, Vinson gives the edge to fruit. Using comparative data on antioxidants in food, he found that fruit contained twice as many antioxidant phenols as vegetables.
In particular, the phenol content of cranberries was five times that of broccoli, according to the researcher. But he cautions that you may not want to ignore broccoli. It and other cruciferous veggies contain sulforaphane, a chemical that has been shown in recent studies to be better at fighting certain kinds of cancer than other food chemicals.
The cranberry is one of North America’s three native fruits that are commercially harvested. Its history can be traced back to this country’s infancy, when it was used by the native Americans to relieve aches and pains. Today, recent studies have shown that cranberries can help prevent urinary tract infections and may reduce the risk of gum disease, stomach ulcers and cancer.
A low-calorie fruit that is rich in vitamin C, the cranberry is popularly consumed in this country as a processed beverage. As a gel or relish, it has become a regular part of the traditional Thanksgiving meal.
In general, processing, storage and heating reduces the antioxidant levels in cranberries: uncooked fruit is the best, says Vinson. On the basis of serving size, 100 percent pure cranberry juice, found in some health food stores, has the highest antioxidant content. Many people prefer not to drink it in this form due to its extremely sour taste, he says.
Fresh and dried cranberries have the next highest antioxidant content based on serving size, followed by cranberry sauce, says Vinson. Cranberry drinks or cocktails contain the least. Most contain only about 27 percent pure juice, he adds.
While the purer forms of the fruit may be better for you than the diluted juice, most people prefer the sweet taste and convenience of the fruit in its drink form, says Vinson. On holidays, the sauce is the most consumed form of the cranberry. The fruit is even available in a concentrated pill form, used primarily for targeting urinary tract infections, the researcher says.
Funding for the current research was provided by the University of Scranton, while ongoing studies are funded by the Cranberry Institute.
The online version of the research paper cited above was initially published Oct. 3 on the journal’s Web site. Journalists can arrange access to this site by sending an e-mail to newsroom@acs.org or calling the contact person for this release.
Joe A. Vinson, Ph.D., is a professor of chemistry at the University of Scranton in Scranton, Penn.
Journal
Journal of Agricultural and Food Chemistry